Jason Fung explains why intermittent fasting diets work

https://qz.com/1419105/a-diet-guru-explains-why-you-should-eat-dinner-at-2pm/

by lxm • 8 years ago

277 325 8 years ago

The way this article is written is very off-putting.

For instance, "We run around chasing our kids to eat cookies and drink juice, and then wonder why we have a childhood obesity crisis. Good job, everybody, good job."

I am not sure if I understand this: "The median daily intake duration (the amount of time people spent eating) was 14.75 hours per day. That is, if you started eating breakfast at 8am, you didn’t, on average, stop eating until 10:45pm."

I certainly spend may be 1 hour eating everyday including breakfast, lunch and dinner.

aaronblohowiak• 8 years ago

From first to last bite is 14.75 hours

kranner2• 8 years ago

The author means time between first and last food intakes of the day, not total time spent eating.

fermienrico2• 8 years ago

I see. So then this statement is not correct "The median daily intake duration (the amount of time people spent eating) was 14.75 hours per day.".

It should be "The time between first and last meal during waking hours".

"The amount of time people spend eating" statement is totally wrong.

megaman82• 8 years ago

"We run around chasing our kids to eat cookies and drink juice, and then wonder why we have a childhood obesity crisis. Good job, everybody, good job."

I literally have seen this happen, where parents chase their kids around cookies and Juice in hand, Literally.

pacaro• 8 years ago

As a parent, I have done this.

It’s hard when an active kid is constantly distracted. It has been a big exercise in discipline (for me) to say that food is eaten at the table at specific times and if she’s hungry, then she can eat more at the next meal. (Obviously baring force majeure etc.)

Oras• 8 years ago

This talk has a nice information about circadian habits if you're interested: https://www.youtube.com/watch?v=erBJuxVR7IE

thebeefytaco8• 8 years ago

Your body is in a 'fed' state long after eating.

gorpomon• 8 years ago

I have to agree on the writing style. I think it's pretty anecdotal that it's "...almost considered child abuse to deprive your child of a mid-morning snack or after-school snack."

I suspect the author has first hand exposure to helicopter parents at soccer games, but should realize that inserting such experiences might get in the way of their main point.

reasonattlm2• 8 years ago

Calorie restriction is probably the most important aspect of short term fasting of the sort achieved by eating only in some parts of the day.

Animal studies show that isocaloric intermittent fasting, altering eating schedules, to e.g. alternate day, while still ingesting the same amount of calories, do have benefits. Those benefits hit many of the same areas of metabolism as calorie restriction, but are still significantly different in their overall operation. They are also not as effective at extending life.

Time spent being hungry might be a good metric, but even that is overly simplistic. Grehlin has all sorts of regulatory connections throughout metabolism, but you can't point to any one thing. All of these dietary changes, less calories or more hunger, cause sweeping changes throughout metabolism that are not well understood as a whole. Cause and effect and which parts are important versus not is very much open for debate for any part of this system.

Further, fasting (or fasting mimicking) for longer periods is clearly a different beast from just rescheduling a few meals. In humans fasting for 72 hours or more results in very different outcomes for immune health than anything less than 72 hours. The longer fast kills up to a third of the immune system, which then repopulates when the individual starts eating again, and thus has very beneficial effects in people whose immune system is damaged or dysfunctional in some way (e.g. as the results of chemotherapy).

Similarly these longer fasts produce changes to insulin metabolism that last for months after the fasting is done, which is not the case for fasting in the rearranging a few meals sense.

roganartu• 8 years ago

This has been posted before, but a good digestible source for the information in this comment is this two-video podcast series: https://www.foundmyfitness.com/episodes/valter-longo

The studies you mention results of (like the 30% immune system culling in a 4-5 day fast) have only been published for mice so far afaik, but they're currently doing human studies.

Also worth noting that one of the points Valter Longo makes quite strongly in these podcasts is that refeeding after the fast is at least as important as the fast itself.

onewhonknocks• 8 years ago

I may have misunderstood, but the article stated the following:

‘The two arms of the study were eating between 8am and 8pm, and the eTRF strategy of eating between 8am and 2pm, but remember, both groups ate three meals per day of the same foods.’

So it's not like the time restricted people took in less calories. Both groups consumed the same total amount of calories.

Please correct me if I'm wrong.

reasonattlm2• 8 years ago

If that study was isocaloric, then good for them for adding some human data to the existing animal data.

I'll qualify my remark: most people who practice restricted eating hours in some way won't count calories or aggressively try to ensure they otherwise eat the same amount and type of food, and thus the mechanism for benefits will be largely that of calorie restriction.

megaman82• 8 years ago

i've been fasting 15-16 hours a day everyday for the last 6 years and it's certainly helped me keep my weight about 10 lbs lower than I would have with just dieting. Before that I always subscribed to 3-5 meals a day hypothesis. Once I switched over to fasting 16 hours, I noticed the effect immediately, by losing 10 lbs in 2 months and have kept it off ever since.

atomical3• 8 years ago

This was not merely an American phenomenon. More recently, China has followed in America’s footsteps with increased snacking. Large-scale surveys show that from 1991 to 2009, the percentage of children and adults who regularly snack has skyrocketed. Among children aged 13 to 18, those who snacked went from 8.7% to 46.3% — a more than fivefold increase. Adults showed the a similar rise from 8.7% to 35.6%.

Even so obesity rates are still low in Asian countries. I guess Asians are enjoying eating throughout the day while still outperforming Americans.

https://www.oecd.org/els/health-systems/Obesity-Update-2017....

aviv• 8 years ago

Fasting, in particular prolonged fasting (up to 40 days of water fasting or 8 days of dry fasting) is the best gift you can give to your body.

sixo• 8 years ago

Support that?

mtgx2• 8 years ago

Dr. Valter Longo says you need only 5 days of fasting.

https://www.ncbi.nlm.nih.gov/pubmed/28202779

Also, it seems to regenerate β cells for Type 1 diabetes humans, although I would imagine the "regular" fasting would do that, too since it's a more extreme version of the FMD:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5357144/

Some interviews with him on it (there are more on youtube):

https://www.youtube.com/watch?v=d6PyyatqJSE

https://www.youtube.com/watch?v=evGFWRXEzz8

https://www.youtube.com/watch?v=vdjGgrh5zSk

viach• 8 years ago

Saying this in public can cause someone to actually follow your advice without consulting a doctor and, well, u know, die.

peterwwillis• 8 years ago

Intermittent fasting seems like it'd wreck your body if you do moderate to intense exercise. So I just fasted, and now I want to do intense cardio.... but I might run out of glycogen or blood sugar. Or I may do a set of weight lifting, but not if I can't eat protein after. So if I do intermittent fasting, I have to come up with a complex schedule to follow in order to get any performance gains.

The whole point of a diet is to be healthy. You don't need intermittent fasting to be healthy. It seems to just introduce complication for a menial improvement in a few measures of health. I'm sure they work, if you can actually stick to them, but there's a lot simpler diets that will also work.

Exercise three times a week. Eat lots of plants. Keep your fat, protein, and simple carb levels within reasonable limits for your age, height and sex. That's not super complicated to follow, and it can fit into basically any schedule.

alokedesai• 8 years ago

Totally anecdotal but I lost 40 pounds in 4 months with IF and I still worked out 4-5 days a week in the mornings. I found it very very easy to follow and my body had very little trouble adapting

rawland2• 8 years ago

"in the mornings". That's exactly the point.

javagram• 8 years ago

So I just fasted, and now I want to do intense cardio.... but I might run out of glycogen or blood sugar

Isn’t that where ketosis comes in? Your body can break down fat and provide energy through ketones.

Some proponents of intermittent fasting would probably argue that simply not eating at certain times is the simplest diet of all since it doesn’t require continually evaluating at each meal what a “reasonable” level of intake is.

ngngngng7• 8 years ago

It takes between 2-10 days to reach ketosis and switch from using carbs for energy to using ketones. Burning ketones also brings less energy than burning carbs, which would not be ideal for cardio.

logfromblammo2• 8 years ago

Fasting followed by cardio is a thing. It's called "bonk training". Running out of glycogen is the whole point of it.

It supposedly helps your body make the switch from glucose and glycogen to body fat and ketones more smoothly. It might have been useful for triathletes and marathoners, if they weren't eating glycogen gel during their races now. You'd carbo-load, hit the wall at mile 20 or so, and just keep going at 80% your normal athletic capacity instead of 70%, because you trained for it. But now, you'd just be left in the dust by someone who has been sucking on a tube of glycogen gel and thus never hits the wall at all.

I suppose it would still be useful for weight loss, if exercising while bonked wasn't self-torture.

gameswithgo• 8 years ago

you can't go as fast

hinkley3• 8 years ago

If you aren’t diabetic, you need to do hours and hours of intense cardio to Bonk (run out of glycogen).

As long as you’re not doing whole day fasts, I don’t think the burden of effort is any higher than the protocol you’ve outlined.

When beginner discipline is the subject, simple rules tend to work better. Your confidence following simple rules allows you to then tolerate more complicated regimes.

Edit to add: Personally, I don’t agree with ADF but for strength training your muscles are rebuilding for days afterward. If you’re trying to gain muscle quickly you’ve probably already decided ADF isn’t for you. But to maintain or gain slowly? I’m not sure it’s going to slow you down that much.

atomical3• 8 years ago

The rules are psuedoscience peddled by health gurus.

i88y6• 8 years ago

I'm not familiar with the term bonk, but I thought the glycogen in each major muscle ran out after about 20m? I've read many times that during cardio the body starts burning fat only after the first 20m. Then it releases a chemical to begin burning calories from fatty tissue.

throwaway5250• 8 years ago

The human body is a stunningly complex evolved system. Intuitive reasoning at a trivial level doesn't really tell you much.

WillPostForFood• 8 years ago

Intuitive reasoning should be suggesting to the parent comment that it would be a huge evolutionary disadvantage if there was no energy available after a short fast.

iopuy• 8 years ago

Perhaps IF will allow you to complete your workout but with no where near optimal performance.

nipar• 8 years ago

There's a rather large movement of strength athletes using intermittent fasting as a tool without these issues.

Glycogen stores aren't easily depleted by day to day life, a regular 8 hour window every day wouldn't affect your evening weight lifting routine. It could affect post-workout only by increasing the time for the glycogen stores to be refilled, but not to such an extent that it would affect your next session.

As for protein after workout, this is largely nonsense. The body is more than capable of regulating it's own protein synthesis over the course of days with both the protein you obtain from food and the stores of broken down proteins from your body. Amount of protein consumed (and type) is the relevant factor and timing plays no significant part unless you are a at a level where you are considered a pro athlete and you're probably attending competitions.

nakedrobot2• 8 years ago

This gentleman has been doing IF for 5 years and he appears to be doing intense exercise.

https://youtu.be/dW_99QcCTzE

rthomas62• 8 years ago

Nah, that's complete BS. Fasting doesn't impair you to the degree you're implying. It takes a good 24 hours to run out of liver glycogen, and even then it's not like you keel over, you just have maybe 85% of non-glycogen-depleted performance. Just have a meal at some point the day before your workout, and you'll be good to go. Blood sugar is also a non-issue when fasting. It is in fact more stable in a fasted state due to very steady insulin levels. Humans are not fragile creatures that need to eat every X hours to do physical tasks.

I do heavy weight lifting in the early morning and fast every day until 2 PM. You don't need to eat protein right after you lift weights, later in the day is perfectly fine. For you optimal gains, maybe, but for gains, no. But I'm not a world-class athlete, I'm a 31 year old with an office job. Intermittent fasting is very popular in the weight lifting world, and it works very well. In my experience, lifting in a fasted state impacts my performance 0%.

raffael-vogler• 8 years ago

This matches my personal experience. I found the gains acquired while IFing - exercise at around 8pm after work and fasting afterwards until noon the next day - to be very consistent and lean.

curun1r• 8 years ago

lifting in a fasted state impacts my performance 0%

Based on my own experiences, I'd actually expect performance to improve since the body isn't using resources for digestion. I'm not a weight lifter, but I know bicycling is significantly harder shortly after eating and my other current sport, freediving, is much, much easier after fasting (my static hold time is close to 2 minutes longer when I haven't eaten in the past ~12 hours).

One interesting observation I've had from freediving is that some of the signals we get from our bodies are far less urgent than we tend to experience them. The main one, in that sport, is the urge to breathe and it's actually not an indication that the body needs oxygen. It is, instead, an indication that CO2 is building up and you can expell it by breathing. Freedivers learn to experience that sensation and push past it.

I'd imagine hunger is very similar. People accustomed to eating whenever they're hungry will panic an experience "low blood sugar" when they don't immediately respond. But we know that humans can go weeks without eating before we die. Pushing past our accustomed non-resistence to hunger will likely be uncomfortable, at first, and then become normal with practice.

lukeschlather• 8 years ago

Intermittent fasting is probably fine as long as you only have an hour or less of exertion on that day. Do 2+ hours though and I think it's a pretty bad idea.

And in my experience even just doing an hour of exercise in a fasted state can dramatically impair my immune system as well as higher brain function.

gremlinsinc13• 8 years ago

Doesn't ketones... work roughly the same as glycogen? I'm doing keto + IF (modified, I have a noon'ish protein drink, and then a meat heavy dinner). Just wondering if you've heard that, I'm new to working out (started at 515 down to 485 in 5 weeks, lots of muscle gains too though so fat loss is probably a lot better than if I'd just dieted alone.)

Edit: I mean, I read an article once that said ketones could enhance performance in weight lifting.. my exercise is Cross Fit training at a Crossfit gym.

kojeovo• 8 years ago

Plan better. If you don't like to train fasted, then plan your fasting / workouts for an hour after you eat. That way you can also have a post workout meal.

i_cant_speel2• 8 years ago

I participate in IF and lift weights after work most days. I think it's mostly about timing. I'm usually done eating for the day around mid afternoon and feel fine working out after work. You don't need protein after you workout. You will be fine if you get enough protein throughout the day leading up to your workout.

throwaway827292• 8 years ago

Were you able to sleep without problems? The biggest problem for me was not being able to sleep or waking up in the middle of the night due to hunger.

rhinoceraptor2• 8 years ago

It's not really that hard to do intermittent fasting. You just eat dinner at 6-8 PM and then skip breakfast and eat lunch at noon.

And IMO the "risk" of bonking is hugely overblown, the worst case scenario is you're in a bike race and you have no energy. Most people are not racing bikes, so I don't see what the big deal is. You stop your workout and eat something. Most people's cardio workouts are not long and intense enough to bonk in the first place, even if they're fasted for 16 hours.

oe2• 8 years ago

I've bonked riding bikes multiple times even when not fasting. I don't see it as a risk, you just limp home @ 20km/h. Sure it sucks :)

smallnamespace• 8 years ago

Intermittent fasting seems like it'd wreck your body if you do moderate to intense exercise.

That just seems highly unlikely from an evolutionary perspective: food sources for most animal species tend to be inconsistent and require physical exertion to exploit (especially for predators).

If hungry + physical exertion = damage, you'd expect that to get weeded out of the gene pool. Human populations have certainly gone through regular famines and starvation during our history, while still needing to farm manually.

BadassFractal2• 8 years ago

You can lift and do cardio just fine even on full blown water fasting for a couple of weeks, or longer if you're already heavily overweight.

It's not the most pleasant feeling in the universe, and your performance won't be anything to write home about, but you will still be pretty functional. Humans have had to go without food for a while for most of their history, so it makes sense we would have adapted to live just fine through periods of scarcity.

RobertRoberts3• 8 years ago

I got stronger and was able to run longer and further when I ate one meal a day. I went from a slow 1 mile run to fast 2 mile run and ended up at 3 miles by the end of one month.

maxxxxx2• 8 years ago

"Intermittent fasting seems like it'd wreck your body if you do moderate to intense exercise. So I just fasted, and now I want to do intense cardio.... but I might run out of glycogen or blood sugar. Or I may do a set of weight lifting, but not if I can't eat protein after. So if I do intermittent fasting, I have to come up with a complex schedule to follow in order to get any performance gains. "

That's not true. You just have to get used to it. When I did boxing I often did two hours intense workout in the evening and didn't eat anything after or hours before. No problems.

toss1• 8 years ago

Nope, it doesn't wreck your body, not even close.

This is because of homeostasis. You normally have close to, iirc, 2000Kcal floating in your blood, intracellular fluid, & cells. If you get too much more, then the pancreas will produce insulin to stimulate your body to store the excess as fat.

But when you are temporarily under-fed as with Intermittent Fasting or Time Restricted diet, the insulin simply doesn't arrive to force it out of the bloodstream so it can maintain the levels; levels can also be restored by converting fat stores to maintain the appropriate blood sugar level.

So, you've always got something like that ~2000Kcal store ready to go, and you don't need to worry about 'bonking' on any normal workout with any normal IF or TR diet.

I personally did once manage to do something like you worry about, during off-season training one year in my career in international-level alpine ski racing. I did a 3-day fast, with a solid weight workout (including big muscle groups) on Day#1. No problem. Then, at the end of fasting Day#3, I felt really energetic, so broke the plan and did another really heavy leg weight workout, which went great. However, about an hour+ afterwards, I felt really wobbly/shaky from low blood sugar. This was fixed with a single big orange juice smoothie. It was really cool to feel it take effect -- within minutes. And, there was no break in the training routine after these events, just continued on as usual.

Admittedly it's a single test, but it shows that it can take a lot more than one workout on a TR or IF day to even get to an out-of-the-ordinary state, and it's easily fixed when you do. Not really anything to worry about.

[Edits - clarity, commas]

thebeefytaco8• 8 years ago

Intermittent fasting seems like it'd wreck your body if you do moderate to intense exercise. So I just fasted, and now I want to do intense cardio.... but I might run out of glycogen or blood sugar.

Have you actually tried working out in a fasted state? I find that I get better performance.

Glycogen isn't depleted as quickly as you think, and blood sugar levels are actually more stable in a state of ketosis when your body is manufacturing its own glucose.

You don't need intermittent fasting to be healthy.

Semantics, but I would say you do if 'intermittent fasting' just means periods of respite between meals so you're not constantly in a 'fed' state. It's only relatively recent in human history that we are even able to be constantly eating.

Keep your fat, protein, and simple carb levels within reasonable limits for your age, height and sex.

You say this, but experts have all sorts of contradictory recommendations for what are 'reasonable' macro limits.

mcculley• 8 years ago

I eat once a day. I run almost every day. I lift weights at least every other day. I have been doing this for years now.

Our ancestors didn't get three meals a day. Millions of our contemporaries get real physical work done without three meals a day or worrying about glycogen or blood sugar. I may be an extreme example, but people worry way too much about skipping meals, in my opinion. It seems like a rationalization for avoiding hunger.

rjbwork• 8 years ago

I do IF. I bike to work each day and work out in a gym irregularly. I have either 1 large meal or 2 small meals in a feeding window each day. I will eat right after cycling in the morning, or right after working out. I don't usually eat after cycling at night. I might have some protein or a small cup of milk at night though. Not technically IF, but also not riding that blood sugar wave all the time either.

WhompingWindows• 8 years ago

IF is actually a simplifier: skip breakfast. If you don't late-night snack, just skip breakfast and you're doing IF.

I've been skipping breakfast for at least 5 years. Assuming the average breakfast would've cost me 5 minutes per day, I've saved over 160 hours not doing breakfast over those years, never-mind the cost-savings and simplification of life that comes with consuming things less frequently.

I've been healthy and fit the entire time I've been skipping breakfast, maintaining a steady weight of 175 lbs at 6'1". I usually have had caffeine, though I occasionally wean myself off. Caffeine (black coffee, straight tea, no sugar) helps with the hunger/IF lifestyle, but it's by no means necessary.

rsync• 8 years ago

"So I just fasted, and now I want to do intense cardio.... but I might run out of glycogen or blood sugar."

I used to think like this, but then I actually tried it and found that not only does a short (16-18 hour) fasted state not negatively impact my workouts but it improves my performance to exercise in a fasted state.

Heavy squat/deadlift day at the gym ... 2 hours of BJJ ... 10 mile run ... these are all examples of things I do in a fasted state. You have no bloodflow diverted to stomach (or other digestive processes) you are fast and light on your feet and your energy is very steady.

Would I embark on a triathlon or an ultra ? Of course not - but whatever fears I had about fasting throwing a monkeywrench into my training were unfounded.

southphillyman• 8 years ago

I have been doing IF for a month or two now. Hard to really quantify it's effects since I've been eating much better and going to the gym during that same time period. Either way I think it's useful if only as a way to make eating at a calorie deficit easier. My biggest gripe is that it's basically impossible to have a social nightlife on the weekends if you can't eat or drink after 8pm

throwaway827292• 8 years ago

Wondering if you could alternate day fasting on weekends. Social life on Saturday evening and restrict yourself to 500 calories on Sunday. I struggle with this as well. Just curious as to how people manage.

ccmonnett3• 8 years ago

If time-restricted eating is having that big of an impact on your life, adapt to it. Eat lunch later on the following days after going out, or - and stop me if this is crazy - don't be so strict about it if your friends want to meet up.

I am a time-restricted eater. I use Zero to track my eating windows and make sure I'm not trending in the wrong direction, and that gives me the peace of mind to let up every once in a while.

Just this morning I broke my fast early because I didn't eat enough last night and I was pretty zonked before my workout (beyond the point I thought would be productive). I ate a few dates, recorded it in Zero, and will live to fast another day.

embwbam2• 8 years ago

For athletes, how does one reconcile IF with the idea that one should eat protein at regular intervals? They seem to conflict.

https://www.climbing.com/skills/climbing-nutrition-how-much-...

sridca• 8 years ago

Biased studies by the supplements industry, most probably.

tejohnso• 8 years ago

Test the idea.

Try dialing back the protein for a while. You might be surprised at how little you need to build muscle and stay fit while at the same time loosing weight.

vlasev8• 8 years ago

I'm not able to look for articles on this right now, but I believe that it was shown that your overall daily intake of protein is more important than the time of ingestion.

embwbam2• 8 years ago

That’s the exact opposite result as the studies listed in the article I posted. Weird.

tzs3• 8 years ago

This needs a title change to the article's actual title:

"A diet guru explains why you should eat dinner at 2pm"

The submitted title:

"Jason Fung explains why intermittent fasting and ADF diets work"

is bad because the article doesn't appear to [1] use the term "ADF" anywhere. Google tells me that probably stands for "Alternate Day Fasting", which also doesn't appear to be anywhere in the article.

[1] I'm saying "appear to" because I've been burned before by browser search functions missing something because the site did something like have some markup interrupt a word or maybe have some invisible character in the middle of it.

ionforce2• 8 years ago

And who is Jason Fung? Does his name have any cachet?

fbnlsr• 8 years ago

Jason Fung is Canadian nephrologist. He's been working with obese and type 2 diabetes patients for years. He's been advocating fasting and time-restricted eating for years to fight obesity and diabetes. He's mostly known for this book "The Obesity Code" in which he details how modern eating habits are wrong and the main cause for the obesity epidemic.

I hope I summed it up well. You might want to look him up on Youtube, he has some really interesting talks.

astura3• 8 years ago

Google tells me he appears to be a doctor, who specializes in renal diseases (nephrologist), has written several books on fasting, advocates fasting for some patients, and runs something called the Intensive Dietary Management program.

prostoalex• 8 years ago

I had the ability to change the title shortly after submission, so just did.

I used the HN's bookmarklet, which I think picked up <title>.

sctb• 8 years ago

Indeed, thanks! We've gone with something closer to what you originally submitted.

wang_li2• 8 years ago

The <title> of the page is "Jason Fung explains why intermittent fasting and ADF diets work" The large type header at the top of the page is "A diet guru explains why you should eat dinner at 2pm".

ngngngng7• 8 years ago

I dislike articles like this as they continue to perpetuate the belief that there are secrets to weight loss. There are no secrets to weight loss. Eat fewer calories than you burn. It doesn't matter if that involves keto, or vegan, or one meal a day. Thyroid problems also don't change physics.

The problem is made worse because overweight people typically greatly underestimate how much they eat, while underweight people (me most of my life) typically greatly overestimate how much we eat. It's nearly impossible to accurately gauge calorie intake without strict calorie counting.

When talking nutrition with people, I'll often bring up the examine.com piece on "does metabolism vary between two people?"(1) And I am always amazed to find at least one person in any conversation that will flat out deny the information presented there. they are positive that if they ate one single slice of pizza a day and nothing else, they would still be fat.

1: https://examine.com/nutrition/does-metabolism-vary-between-t...

electrograv8• 8 years ago

There are no secrets to weight loss. Eat fewer calories than you burn. It doesn't matter if that involves keto, or vegan, or one meal a day. Thyroid problems also don't change physics.

That's like saying "There are no secrets to space flight: For every action, there is an equal and opposite reaction. It doesn't matter if that involves Hydrogen, Hydrazine, or just big tubs of water -- throw them one way, and you'll move the opposite. Your choice of fuel doesn't change physics."

Of course fundamental physics laws hold. But some fuels and systems of using those fuels are more effective than others.

When it comes to diet, different foods and eating patterns do have different effects on our endocrine system, and that does affect how viably we can sustain ourselves on less calories. Different foods will also have different proportions that are retained vs passed the same day.

Unless you also capture ALL your own human waste, and measure it in a 'bomb calorimeter', counting calories (intake only) is not nearly as useful as you seem to think. If you disagree, drink 2000 calories of olive oil every day and eat nothing else, then come back after a year and tell me that calories are all that matter :) Disclaimer: Don't actually do that, because you would starve to death.

projektir5• 8 years ago

People had stable weight without any special knowledge for most of human history. It's something we generally should know how to do automatically. It's very strange to compare it to spaceflight, as if we're only just now discovering how to do it. This just goes back to OP's point. There's a lot of energy being spent on making weight gain and loss be some mysterious, inscrutable thing. Now we're comparing it to space flight?

parthdesai• 8 years ago

If you break it down into carbs, fats and protein, calorie in calorie out model does wonders. OP is right, weight loss is hard work. Frankly, people want to believe that there is an alternate method because a lot of them are just lazy.

Also, it's easier to maintain weight than to loose/gain weight. So once you have lost that weight, it's much easier to be at that weight. Of course you lost a huge amount of weight in a short span, this won't be true.

bshoemaker• 8 years ago

This comment has very little to do with the comment above it, which makes the point that weight is dictated by net calories, with very few exceptions.

atomical3• 8 years ago

When it comes to diet, different foods and eating patterns do have different effects on our endocrine system, and that does affect how viably we can sustain ourselves on less calories. Different foods will also have different proportions that are retained vs passed the same day.

People who care about this aren't interested in the secrets of the endocrine system. They are interested in how they can remain trim while eating rich food like meat and dairy. These folks like fasting because they can eat one large meal and get more stimulation from the food.

auganov4• 8 years ago

No you wouldn't starve to death. If you didn't take a decent multivitamin you might develop life-threatening nutrient deficiencies, yes.

Also it's not as if we have a great understanding of how different foods influence our food consumption patterns.

I totally agree with ops point. Almost anytime the topic of nutrition comes up people are either unaware of the basic mechanics or have been convinced they're somehow fake [0].

[0] as in that there are huge differences in metabolic efficiency between foods or that people's BMRs usually differ greatly.

goostavos4• 8 years ago

I always see this response in these threads and get a little frustrated. I feel like it purposefully misses the forest for the trees a bit.

Sure, at a super granular level, different foods affect you differently, trigger different biological responses, etc.. etc.. but if you zoom out, the details just don't matter. If you're under calories, the weight will come off.

Nobody is suggesting to "drink olive oil." you can keep you normal diet, just eat less of it, and magic will happen.

darkerside• 8 years ago

The premise you've presented fascinates me. I wonder what would be the impacts of a 2000 calorie olive oil diet. Is it truly a starvation diet (due to inability of the body to process those calories)? I generally agree with the "calories in, calories out" principles of weight management, but I could see this being a useful counterexample.

natural219• 8 years ago

Ketosis reduces your appetite substantially.

ngngngng7• 8 years ago

Maybe? It definitely hasn't been shown to be any more effective than a fat free diet.

thrower123• 8 years ago

Totally. I'm not convinced that keto is any more efficient at burning fat, but eating my normal meat-starch-vegetable meals without the starches probably cuts 1000 calories per day out, so there's the calorie restriction. The magic comes in where I'm not ready to gnaw my arm off or murderously hangry on that amount of calories, versus trying to just eat less of the full blend.

dawhizkid• 8 years ago

There are plenty of ways to optimize fat burning/weight loss beyond eating fewer calories. When you eat matters. Working out in a fasted state will accelerate fat burner vs working out after eating a meal. Eating a similar number of calories in a keto diet vs a carb-heavy one while maintaining a calorie-deficit will also accelerate fat burning/weight loss.

elbear3• 8 years ago

Of course things are not so simple. Calories in/calories out partially applies to weight gain/weight loss, but it's not the complete story. Hormones also play a role.

That's why people start to gain weight as they grow old, even though they eat the same. It involves testosterone/estrogen and an enzyme called lipoprotein lipase.

ngngngng7• 8 years ago

It involves testosterone/estrogen and an enzyme called lipoprotein lipase.

This is just a variation of the thyroid problem reasoning. Hormone changes with age or thyroid issues might change your resting metabolic rate over time by 100-200 calories per day (a single candy bar of calories). But that doesn't curse you to be fat, which is what I am trying to disprove. You will then need to adjust your intake/exercise level accordingly to the new resting metabolic rate.

NickM• 8 years ago

The calories in/out model is technically true, it's just not very useful. It's like saying "there's no secret to how a jet plane works, you just need to have enough lift to counter gravity, it's basic physics." Well, sure, but there are a lot of other variables to consider that will dictate how hard/expensive it is to build a working aircraft.

Playing with other variables besides calories, like the specific foods you pick and the timing of meals, can produce dramatic, measurable health changes and make a huge difference in how hungry you will feel at different times of day.

EDIT: I just saw the other reply someone wrote that used a rocket analogy instead of a jet plane analogy, funny how we both independently came up with such a similar response.

mikevm• 8 years ago

Playing with other variables besides calories, like the specific foods you pick and the timing of meals, can produce dramatic, measurable health changes and make a huge difference in how hungry you will feel at different times of day.

It is true that the kinds of foods you eat may help you with maintaining a caloric deficit -- for example, eating high-volume foods such as vegetables, or low-GI whole-grain carbs may help you feel "full" longer than low-volume foods with high caloric densities (candy, snacks, sodas). But the most important thing is still calories. See a recent meta-analysis on this: https://jissn.biomedcentral.com/articles/10.1186/s12970-017-...

Also, timing of meals is actually not that important for weight loss. It is somewhat important for sports performance (e.g., timing carb intake around sports activities). There was a meta-analysis a few years ago that gave more specific recommendations: https://jissn.biomedcentral.com/articles/10.1186/s12970-017-...

projektir5• 8 years ago

The calories in/out model is technically true, it's just not very useful.

It's plenty useful. The biggest barrier I've seen so far in people trying to lose weight is that they just plain don't believe it, and think it won't work. They think they need some complicated specially tailored diet where they need to pick out specific foods, eat foods they don't like, eat at special intervals, and so on.

Playing with other variables besides calories, like the specific foods you pick and the timing of meals, can produce dramatic, measurable health changes and make a huge difference in how hungry you will feel at different times of day.

That may be true, but various tricks you might choose to apply to your diet should come /after/ you know how many calories you're consuming. It's a question of where your attention is directed. The purpose is still to reduce calories, and preventing hunger in whatever way works for you or distracting yourself or maintaining a schedule are all just means to the same end: to reduce how much you're consuming.

The problem I see is that people seem to not agree on that /end/ and think they're trying to accomplish something else, but I'm not sure how that's supposed to be measurable or reliable.

bootsz• 8 years ago

Playing with other variables besides calories, like the specific foods you pick and the timing of meals, can produce dramatic, measurable health changes and make a huge difference in how hungry you will feel at different times of day.

Exactly. Try to stay under your daily calorie quota eating just processed carbs/sugar and you're gonna have a bad time. Will you still lose weight? Sure, if you can actually withstand feeling hungry constantly. Compare that to the same # of calories from veggies and fat and most people will tend to feel much more satisfied overall. I've been doing keto for 12 weeks along with intermittent fasting and this has been the case for me. I can easily get a sizable daily calorie deficit without really trying and rarely feel hungry.

e1ven• 8 years ago

I don't think many people believe there are "secrets" involved, but there are many factors which make sticking to a diet easier for people.

The linked page talks about this quite a bit - Trying to control for hunger, fullness, desire to eat, etc.

"This was a randomized crossover, isocaloric and eucaloric study. That is, all patients did both arms of the study eating the same foods and the same calories and then compared against themselves. ... Those who restricted late-night eating had less desire to eat, but also less capacity to eat. They couldn’t eat more at night even if they wanted to. That’s amazing, because now we are working with our body to lose weight instead of constantly fighting it. "

Respectfully, I'm not really sure I understand how your critique applies to this article?

calpaterson• 8 years ago

There are no secrets to weight loss. Eat fewer calories than you burn. It doesn't matter if that involves keto, or vegan, or one meal a day. Thyroid problems also don't change physics.

Unfortunately that is not true. Different foods are metabolised differently. It is not just "calories in, calories out".

msiyer17• 8 years ago

If I eat 5 burgers a day and reduce it to 2 a day, I will lose weight. However, no amount of burgers is good.

For more than a decade I had been fasting intermittently. I ate one very huge meal everyday. Typical Indian meal with fair bit of non-veg included. I was not in the best health possible.

A year ago, I got rid of non-veg from my diet. Things improved a bit, but I wanted better results. One month ago, I went fully raw - only raw fruits and no vegetables. I lost many pounds and everybody notices, my sinus troubles have vanished, I feel and look good overall.

I eat more than ever, but am losing weight.

projektir5• 8 years ago

If I eat 5 burgers a day and reduce it to 2 a day, I will lose weight. However, no amount of burgers is good.

What's so terrible about burgers? From what I can see they're much less harmful than just obesity in and of itself.

barbecue_sauce2• 8 years ago

This is known as the "Steve Jobs" diet plan

Udik2• 8 years ago

Only eat raw vegetables and you'll lose even more. Reason: they're mostly water anyway and less sugary that fruits, so less carbs. You can fill your belly with them and you'll get very little calories.

Another possibility: only eat naturally blue foods. Or only eat foods beginning by 'K' (a different one each day of the week).

agumonkey• 8 years ago

There are other benefits beside weight loss. Changing the way you eat seems to be linked to a lot of part of your system.

dionidium• 8 years ago

It's nearly impossible to accurately gauge calorie intake without strict calorie counting.

Yes, but you can get most of the way there just by counting for a while, so that you build a model in your head for how many calories different foods have. Unless you've counted before, the results can be surprising. Stopping at Starbucks for a snack and deciding between a cake pop [0] and the chocolate chip cookie [1]? The cookie has 380 more calories.

Thinking about grabbing a quick lunch and trying to decide between a burger from Shake Shack or a burrito at Chipotle? That burrito could easily have 1200+ calories [2]. The burger has 530. [3] (A bowl without rice at Chipotle, on the other hand, can have as few calories as the burger. So, again, knowing that difference can help you make better choices.)

These are just random examples from my own life, recently. Knowing these differences makes a difference (especially over the course of many meals).

[0] https://www.starbucks.com/menu/food/bakery/cat-cake-pop?food...

[1] https://www.starbucks.com/menu/food/bakery/chocolate-chip-co...

[2] https://www.chipotle.com/nutrition-calculator

[3] https://www.shakeshack.com/food-and-drink/

ericb• 8 years ago

There are no secrets to weight loss. Eat fewer calories than you burn. It doesn't matter if that involves keto, or vegan, or one meal a day. Thyroid problems also don't change physics.

You seem focused on the physics and materialist viewpoint, but it seems like you are taking that line of reasoning just far enough where we can be judgmental and snarky about "secrets."

What if we take your thinking a little farther and think about the brain chemistry and drives that affect behavior. We are just materialistic machines, right?

Ever seen a sick person who just doesn't want to eat? Or a skinny person with little interest in food? Ever try to hold your breath for 3 minutes? This should, in theory, for the average person be possible. But for some reason it is really really hard.

What if, these diets don't affect the physics of weight loss, they affect the hunger drive--the chemicals in the brain? Do we still get to ride our moral high-horse then?

Or what if there are drives and chemicals in the brain and even the metabolism itself fights back.

https://www.scientificamerican.com/article/6-years-after-the...

ngngngng7• 8 years ago

Excellent points

Or a skinny person with little interest in food?

And yes, that's me all the time.

What i'm saying is, everyone has a resting metabolic rate. That rate is relatively stable among the entire human population. If you eat more than your metabolic rate, you gain weight. Less, and you lose weight.

Most readers on hacker news are saying "duh ngngngng, but you're oversimplifying". Correct, I am. But the reason for that is I believe most Americans (maybe other countries too), do not believe the information I just presented. Most Americans think if they are fat that their resting metabolic rate must be 1500 calories different from most skinny people.

I think this creates a sense of hopelessness. "No matter what I eat, i'll be fat. But no matter what ngngngng eats, he stays skinny!" Even though the reality is my metabolism is average, and the referenced overweight person probably has a similar metabolism as me.

cptskippy• 8 years ago

That article doesn't disagree with what you're saying. My two takeaways were:

1) We snack more now than we did 50 years ago and those extra calories are probably why we're fat.

2) Reducing the window of time that you eat during the day reduces your desire to eat and your ability to consume.

I'm not sure how you took that as perpetuating a secret to weight loss.

werbel• 8 years ago

As others mentioned there’s an aspect of efficiency there but I think there’s something more important.

The whole discussion revolves around losing weight while diet and nutrition is not really about that. It’s about how to eat to stay healthy. Not being obese is just a part of that.

If you consider the bigger scope you’ll realize that despite the fact it came out from Neil deGrasse Tyson mouth, in this context it’s just a stupid thing to say.

tzs3• 8 years ago

The problem is made worse because overweight people typically greatly underestimate how much they eat, while underweight people (me most of my life) typically greatly overestimate how much we eat. It's nearly impossible to accurately gauge calorie intake without strict calorie counting.

This suggests that you might be able to take pairs of people, one who is overweight and one who is underweight, and help both of them by simply arranging for them to eat every meal together and do all their snacking together.

For each meal or snack, each buys or prepares what they normally would, but before they actually consume the food, they each exchange half of their food with the other.

There...an easy to follow diet, without strict calorie counting, that should move the overweight person to a lower weight and put some weight on the underweight person.

You could probably build a reality TV show around this. Half the contestants would be people wanting to lose weight, and half would be people trying to gain, with the lowest weight person in the first group being substantially heavier than the highest weight person in the second group.

Each week, there would be challenges and contests which determine priority for picking who your eating partner will be for the next week.

Pick the contestants from a wide range of culinary cultures and ethnic and religious backgrounds so that some potential pairings would be difficult for the participants, and so doing well in the challenges is important.

ngngngng7• 8 years ago

I've actually had this idea for years. When I was a teenager, I was constantly told by classmates or family members, "I wish I was like you and could eat anything I want and stay so skinny!"

I didn't understand the information in my original comment at the time, but it occurred to me it might make a fun documentary to have me live with someone morbidly obese for a month and eat everything they eat when they eat it and see if I gained weight.

jmull3• 8 years ago

Telling people to eat fewer calories than they burn is useless without telling them how.

As you yourself acknowledge, it’s not that simple. You use calorie counting to stay on track — but that’s another secret to weight loss, isn’t it? You may not think of it that way because it works for you (which is great by the way), but that’s what it is.

But now we’re getting to the meat of the issue. Eating fewer calories than you burn results in weight loss, but how? We should be focusing on the methods that work for many people. If we know what they are, we can advise people attempting to lose weight to try them and hopefully most wont have to try too many before they find one that works for them.

As far as I can tell, the three methonds that work well for many people are: (1) strict calorie counting (usually app + food scale), (2) intermittent fasting — which is what this article is about — and (3) keto.

Of course, it’s fair to scoff at and criticize the methods that usually don’t work well especially when results are oversold especially in money-making schemes. But this guy is just promoting IF in a fair and reasonable way.

Also, there is a reasonable chance IF has health benefits beyond weight loss, which is potentially a reason to prefer it over calorie counting (although I found that when calorie counting I was effectively doing a mild IF anyway)

songshu• 8 years ago

It's like saying there are no secrets to computing and to just imagine a computer as a Turing machine, forget about stuff like pipelining and caches and whatever. On the other hand, I do believe the supposed "secrets" have actually been known for a long time. Here's my favorite article about it: http://www.grubstreet.com/2018/03/ultimate-conversation-on-h...

sooheon4• 8 years ago

Damn, this thread is full of actual good analogies today! Thanks for this one :)

theorique• 8 years ago

There are no secrets to weight loss. Eat fewer calories than you burn. It doesn't matter if that involves keto, or vegan, or one meal a day. Thyroid problems also don't change physics.

The point of the article is, the timing of feeding vs fasting leads to differences in fat storage.

The work of Dr Fung, among others, suggests that concentrating eating into a few (4-8) hour period per day causes better outcomes than feeding during the entire waking period.

Same thing with the balance of macronutrients. Tuning the ratio of fat:protein:carbohydrate can make a diet more filling and more sustainable on fewer calories. This enables that "calories in / calories out" rule to actually work and cause reduction in stored body fat.

ha8o8le• 8 years ago

There's way more to this story as people are pointing out.

I talk about a lot of this stuff with nutrition experts on my podcast http://peak-human.com and am getting the author of this article on soon.

vlasev8• 8 years ago

Unfortunately the human body is quite a bit more complicated than that and a single article on examine.com is woefully inadequate at capturing the complexities. While people's metabolism doesn't seem to vary too much from person to person, it does tend to vary a lot within the same individual based on lifestyle choices. Whether I choose to eat or not, or choose how much to eat, my metabolism can vary.

When you consider your glycogen reserves, carb vs fat metabolism, insulin, ghrelin and other hormones, you get a rather complex machine. And what's really frustrating is that you are technically correct, in a sense. Eat fewer calories than you burn and you will lose weight. But that simplification borders on the dangerous. What's missing is that your body is not some passive observer, but an active participant, trying its best to help you survive.

Your body is amazingly good at adjusting how much you burn. When you cut calories, say 500 a day, your body will tend to compensate by burning a little less by reducing its temperature, by reducing fidgeting, by reducing your mood even! You'd need to cut 500 calories ABOVE that difference. So you end up having to cut closer to 750-1000 calories per day to get the same effect. Whereas when you fast, your metabolism rather obnoxiously tends to rise.

It ends up being healthier (and much easier) to eat 3500 calories less in one go, rather than splitting the difference across 7 days.

Axsuul• 8 years ago

Calories in/calories out is a simple pipe dream that conveniently ignores the deleterious effects that hormones can have on your metabolism.

There are tons of people out there intaking less calories than their BMR and not losing weight because they have thyroid issues, are insulin resistant, etc.

jgrahamc• 8 years ago

Am I meant to know who Jason Fung is? Means nothing to me.

wishinghand2• 8 years ago

Just the same as some readers not knowing Alan Kay or Richard Stallman.

projektir5• 8 years ago

This doesn't sound like it was controlled for simply eating less calories.

oxymoran• 8 years ago

Because it wasn’t and that’s not the point. Everybody already knows a caloric deficit results in weight loss. The point, and the control, was that the same person, eating the exact same caloric intake exhibited different outcomes solely based on the time of day the ate.

projektir5• 8 years ago

Everybody already knows a caloric deficit results in weight loss.

I can assure you "everybody" doesn't already know that, in fact, this seems to be a _minority_ opinion.

The vast majority of people seem to think they need a diet (i.e., restriction on type of food) to lose weight. The only people I know who are actually on CICO are people I encouraged to try it.

toasterlovin3• 8 years ago

Caloric deficit does not result in weight loss. It results in a smaller energy input. That smaller input can be balanced two ways:

1. Utilizing stored calories (which will result in weight loss).

2. Expending less energy (which would not result in weight loss).

Realistically, reducing calories probably results in some combination of the two, with things tilting toward expending less energy as your body gets below a body fat percentage that it "wants" to be at.

freecodyx2• 8 years ago

as a muslim, i have to fast for a whole month (non stop) each year, it's hard, but i can clearly see the benefits during and after.

swebs• 8 years ago

What do you mean by non stop? Does that mean you consume 0 calories for the entire month?

wishinghand2• 8 years ago

Just during daylight hours.

ccmonnett3• 8 years ago

Non-stop as in on all days in Ramadan consecutively. It's quite trendy to do alternating fasting cycles like "5:2" (five days 'normal', 2 days fasting, typically separated). Ramadan is ~30 days of fasting during daylight hours in a row.

ThirdFoundation• 8 years ago

What benefits have you personally seen? Genuinely curious.

freecodyx2• 8 years ago

Personally, i don't have issues with overweight. but before last ramadan (June), i was having some digestive issues, i lost appetite, and i was feelings like i need to vomit, but just after ramadan, everything is back to normal, i recovered quickly, and everything is back to normal,

Also i was starting to get used to drinking beers (alcohol), but i had not to drink the whole month, and since then i don't drink (i don't miss it) for non muslims it might seems like it's crazy thing to do and you are harming yourself, but it's really easy for us and we miss it.

barbecue_sauce2• 8 years ago

THE Jason Fung?

gdsdfe• 8 years ago

It's fascinating that we're still using the term 'guru' in 2018

tzs3• 8 years ago

As always for this kind of article, some of the comments have turned to more general discussion of human diet and metabolism. There was an very interesting article relevant to that in Vox.com a little over a month ago [1]:

"What I learned about weight loss from spending a day inside a metabolic chamber"

[1] https://www.vox.com/2018/9/4/17486110/metabolism-diet-fast-w...

socalnate1• 8 years ago

Thanks for sharing; really enjoyed this.

mancerayder4• 8 years ago

Having gone back and forth on this (a 16-hour fast for a several week period more than one time), and having read a bunch on the topic, I've concluded thus far that, fundamentally, there's no one-size-fits-all for human bodies. In other words, human bodies are so complex that results for almost any food program vary a lot.

Aside from the individual factors, which include your gender and age and whatever uniqueness about your body that we don't know yet (like effects of gut flora on metabolism), there's the type of exercise you do.

If you do long distance running or cycling, at one extreme, it's obviously a no-go. If you do a short conditioning workout or strength workout right before breaking your fast (if you're lucky enough to have a schedule that allows that), that sounds okay.

There's some speculation that fasting 'resets' the gut flora, or that there's a benefit to 'giving the digestive system a rest', then there's some science around the impact on fasting on circadian rhythm reset benefits, some other science around fasting to 'reset the immune system.'

My personal experience was that I didn't get much benefit in terms of body fat cutting, I didn't notice a performance increase or decrease in the gym (where I do strength training and calisthenics primarily with a bit of cardio). I DID notice I was obsessing over food in the mornings and when 2pm came around, there was a feeling of accomplishment.

I'm not sure it was worth it for me. As for everyone else, the jury's still out. It's just that I'm not convinced it'll be back within my lifetime in this complex area of study.

msiyer17• 8 years ago

Why do all wild lions look the same? Are their bodies not complex like ours?

Fasting is followed by animals too. When they fall sick they fast. Deliberate fasting in humans is a necessity because humans eat unnatural food.

soared• 8 years ago

Animals also eat their own throw-up, that doesn't mean we should too.

toasterlovin3• 8 years ago

Lion diets haven't changed since lions became a distinct species. Human diets have changed drastically in the last 10k years. And there are well known examples of humans evolving adaptations to changing diets (lactase persistence in Northern Europeans being the most obvious). It would be crazy to think that other, less obvious adaptations to diet haven't occurred in basically every other region with a distinct diet.

groby_b4• 8 years ago

Oh dear, it's not entirely clear where to even start with this.

Let's begin with the fact that we're not lions. We're not even carnivores. And there's some research evidence that in omnivores, short-term fasting leads to increased acidification in the stomach, while it doesn't for carnivores - that's a rather substantial difference.

Then, we come to the magic of "unnatural" food. We'll leave out the fact that such a thing doesn't exist and assume you mean processed food. What exactly is the proposed mechanism here where fasting is beneficial? And why can't that same mechanism be achieved via less processed food? And which processing are we even talking about?

Also:

Why do all wild lions look the same?

Have you actually seen wild lions? They look roughly the same in the sense that "all white people look the same". I.e. not at all.

vlasev8• 8 years ago

What about water fasting for longer periods? Have you gone 24/48/72 hours without any food? I find that longer fasts tend to work better for me, since I end up eating more calories in the 8 hours window in a 16/8 IF regime. But if don't eat for close to 36 hours, even with the increased food intake, I would still come out ahead.

If you fast long enough, say 48 hours I think, your body enters a mode of "autophagy", which is highly beneficial. So there's that.

verall• 8 years ago

I fasted for around 40 hours once, and by the end I felt extremely low energy. I noticed I was avoiding standing, leaning on things if I did, and my normal foot-tapping or idle movements completely stopped.

Does anything like that happen to you? Do you know if it would feel better during autophagy?

BadassFractal2• 8 years ago

I believe autophagy doesn't kick in for the first 5 days, so if you want to preserve all muscle mass, that's the window to stay under. Once you go after that, the changes aren't that dramatic either, so you'll recover whatever muscle loss you incur fairly quickly as long as you're fasting while still having fat reserves. Once you're out of those, fasting is a bad idea, in the sense that you will start dying.

https://www.amazon.com/Complete-Guide-Fasting-Intermittent-A... - another book by Jason Fung that covers water fasting more in depth.

bcheung• 8 years ago

I've done extended water fasting several times. 5-days, 7-days, 10-days, 17-days. It's MUCH easier for me to fast for 7-days than do 7 24-hour fasts. I feel much less hunger and fatigue when doing extended. All the negative experience is in the 1st day or 2 and gets really easy by day 3. So the result is much less net discomfort with extended fasting.

wdewind5• 8 years ago

So Jason Fung is actually misreading this study. The main issue around all of this is: If someone eats the exact same amount of calories but spreads it out throughout the day does this have any effect on metabolism or weight? So far IF proponents have had a really hard time showing isocaloric diets have any different outcomes regardless of meal timing. This study attempts to address this issue by serving the same amount of food, but it does not ensure that the same amount of food is consumed, and so we are right back to where we are with all IF studies that show results like this: IF contributed to the participants abilities to eat the right amount of food, but there is still not a single study showing isocaloric intake and any different outcomes.

Besides that the standard: this is done on 8 people over a very small period of time, so it's at best a pilot study anyway.

IF may be a great way for some people to comply to their dietary goals better, but there is still not a single study that shows it actually does anything besides that.

jmull3• 8 years ago

Which study are you referring to? He references different studies to make different points and I can’t tell which one you’re talking about.

voidlogic• 8 years ago

IF may be a great way for some people to comply to their dietary goals better, but there is still not a single study that shows it actually does anything besides that.

I think Keto is the same way. There isn't strong evidence of a clear metabolic advantage (I'm not saying there is not one), but its one of the few ways I have eat a caloric deficit and not hate my life.

I think if IF and Keto take people off a insulin roller-coaster and let them comply with their targets, that is still a huge win, in and of itself. We know their are other benefits too such as depletion of stored liver fat or better acute insulin responsiveness, but these may be gravy, the real win is in compliance IMHO.

foldr4• 8 years ago

If you do long distance running or cycling, at one extreme, it's obviously a no-go.

This isn't obvious to me. I don't run seriously, but I don't find that fasting has any adverse effect on my performance. If you are talking about running a marathon or something like that, then sure, but hardly anyone is doing exercise that intense multiple times a week, so you could still have fast days.

16 hours really isn't a very long time to go without food. Your body can cope with it fine, even if you're doing quite intense exercise.

scott_s• 8 years ago

I imagine that if you're training for an endurance-based competition, getting all of your required calories in one sitting once a day will either not happen reliably, or be really uncomfortable.

Tharkun2• 8 years ago

Exactly. Your body is very good at storing energy (fat). It's also pretty good at burning fat while running, especially at the slower pace that is typical of long distance running. You can eat a couple of thousand kcal in one sitting, but you can store a hell of a lot more around your waist. Getting enough water and electrolytes during a long distance run is much more important than having breakfast beforehand.

denebo• 8 years ago

It's "obvious" to those unfamiliar with fasting. Once you're used to fasting, what was previously obvious and intuitive gets thrown out the window.

shmat• 8 years ago

I cycle 4 days a week for 2 - 4 hours each ride. I have tried various kinds of fasting including 16:8 and 5:2 and they've all been a disaster. I have extensive split times for the same rides and after accounting for wind/temperature, when fasted, I slow down about 3% after 90 minutes. After 2 hours, I slow down 5%. After 3 hours, I slow down 15% and feel terrible. I also feel more tired for the rest of the day. Even if I don't fast on ride days and fast on the other 3 my ride times are slower and my recovery is harder. I've kept up the fasting for at least 3 months to see if my body will adjust, but it does not work for me. Now, I practice 16:8 in the winter when I'm riding less but not during the main season.

gamblor9564• 8 years ago

If you do long distance running or cycling, at one extreme, it's obviously a no-go.

Not obvious at all. My best marathon times followed training cycles where I didn't eat breakfast before long runs (i.e., 13+ miles).

loceng2• 8 years ago

As you point out there are cycles that will influence the experience of a fast - not limited to physical energy available at any time, possible discomfort due to coping mechanisms food/eating may part of, and so on. I am still managing significant chronic pain, and although sugar is bad for inflammation - which has its own problems - it is "comforting" and numbs the pain to some degree as well. I generally go through cycles of pure water fasting for 3 days to break the sugar cravings and to bring back mental clarity, at the cost of the remaining pain localizing and becoming sharper. Still waiting for refuge from pain, potentially some more healing next week, and then have to wait another ~3 months for another stem cell treatment.

parliament322• 8 years ago

If you do long distance running or cycling, at one extreme, it's obviously a no-go.

I always do my runs in the morning, right out of bed, fasted. Your body is very good at storing energy and using it later, I've had no issues (if anything, trying to eat before a run just causes problems for me).

poslathian• 8 years ago

Same - and I’ve recently upped my long runs to 12mi, which I do before eating anything. I’m sure there are limits where you need to fuel before or during an endurance activity, but I’m surprised and happy to not have found it yet.

steve_adams_862• 8 years ago

I found I stopped hitting walls and levelled out my pace a lot once I started running while fasted. I was doing IF for about two years while running 20-30km once per week or so, and I liked it quite a bit. Eventually I moved in with my girlfriend and her and her son found it too weird that I didn't eat with them - I'd just hang out while they ate the food I made. That's the big barrier with IF. Everyone wants you to eat, so I stopped doing IF consistently.

starpilot• 8 years ago

I bonked out hard after going on a run after eating only a banana since waking up. Now I always make sure I've had at least a few hundred calories

tokyodude• 8 years ago

my body does not work right out of bed. it takes me 30-45 minutes until I feel like I can make any exersion. if I force it I have zero energy. I don't eat first but I can't exercise right out of bed.

arif_sohaib• 8 years ago

Sounds like Ramadan. Especially the "obsessing over food" part. Some of us actually end up fatter after the month of 16 hour fasts.

msiyer17• 8 years ago

If you are "obsessing over food" during Ramadan you are doing it wrong.

user3359• 8 years ago

Having spent time with Muslim friends around Ramadan, I have no doubt that this is due to OVEREATING after sunset and before sunrise. I've seen people pack 3000 calories into 2 meals when they should be getting 1500-2000, especially with the reduced activity levels due to lower energy.

Fasting doesn't give you the ability to break rules of biology.

holri• 8 years ago

If you do long distance running or cycling, at one extreme, it's obviously a no-go

I did a one week Buchinger fasting and did several long distance runs (as I always do) after 2 days fasting. (after switching to cetogen burning) I noticed a small decrease in power, but in no way this was a no go. It was actually fun.

steve_adams_862• 8 years ago

Likewise, I found my energy was slightly lower but it was also very consistent. Like burning hardwood. You don't get explosive power, but you can go steady without hitting walls.

mtgx2• 8 years ago

Did you continue to eat high-carb meals after your fasting? I recently had to give up eating keto for a few weeks and then I noticed I got very hungry in the mornings. On keto I would normally eat around noon without much effort. If your body gets used to high insulin it will naturally make you crave food more often.

mancerayder4• 8 years ago

To all those who replied saying they fast and do long distance running, I guess I stand corrected. But I'd be concerned about muscle catabolism, as if the body is asked to retrieve energy due to demands placed on it, surely after a prolonged fast the muscle tissue is a strong candidate.

foldr4• 8 years ago

Well we're talking about intermittent fasting here. You'd gave to be pretty damn skinny for your body to have run out of fat to burn within 16 hours (max).

arcturus17• 8 years ago

I've concluded thus far that, fundamentally, there's no one-size-fits-all for human bodies

Exactly. I've had pretty bad experiences with a no-breakfast IF. After two or three weeks on the diet, I get insomnia, and I definitely feel more stress. On the latter, I've read that IF raises cortisol levels, so that might be it. That's actually pretty good when you're at low baseline stress levels (it puts you in a state of "positive anxiety"), but when you're stressed from work it can take you over the limit.

Ultimately I stopped it because I'm already at around ~12% BF - I couldn't even say why I was doing it anymore. Three healthy meals a day and regular exercise does it for me.

If this works for people without negative consequences, then all the more power to them. I really like how it goes against the "shove things into your mouth at every waking hour" philosophy, which has become a ridiculous dogma in modern society.

koube3• 8 years ago

I suspect there's no objective way to discuss a topic while it's in the hype cycle. Mindnfulness meditation seems to have dubious benefits, the uberman sleep cycle has all but disappeared, but during their hype cycles there was no way to sit down and discuss whether they actually do anything. There were too many people singing praises and making tons of claims, and there's really no way to dispute them. The science seems to never happen on these types of things as well, so just waiting doesn't seem to be the answer either.

loceng2• 8 years ago

The biggest problem is many of these practices are often done and discussed in relative isolation of other holistic practices.

jklinger410• 8 years ago

For all we've done in science, it seems like we still have a huge correlation != causation issue.

I just had someone tell me that the amount of auto accidents increase between 2 and 4pm in the US. This somehow showed that people make poor decisions during that time because of our sleep cycles? I was met with much resistance when I pointed out that there are fundamentally different people driving during 2 and 4pm than 8am or 5-6pm. The numbers don't lie, right? Just how you read them...

Anyway, I'd love to see the science that mindfulness and meditation have dubious benefits. I am such a believer in those practices, I have a hard time understanding the argument that they are not beneficial.

koube3• 8 years ago

https://www.scientificamerican.com/article/wheres-the-proof-...

The new paper cites a 2015 review published in American Psychologist reporting that only around 9 percent of research into mindfulness-based interventions has been tested in clinical trials that included a control group. The authors also point to multiple large placebo-controlled meta-analyses concluding that mindfulness practices have often produced unimpressive results. A 2014 review of 47 meditation trials, collectively including over 3,500 participants, found essentially no evidence for benefits related to enhancing attention, curtailing substance abuse, aiding sleep or controlling weight.
Van Dam acknowledges that some good evidence does support mindfulness. The 2014 analysis found meditation and mindfulness may provide modest benefits in anxiety, depression and pain. He also cites a 2013 review published in Clinical Psychology Review for mindfulness-based therapy that found similar results. “The intention and scope of this review is welcome—it is looking to introduce rigor and balance into this emerging new field,” says Willem Kuyken, a professor of psychiatry at the University of Oxford in England, who was not involved in research for the new report. “There are many areas where mindfulness-based programs seem to be acceptable and promising, but larger-scale randomized, rigorous trials are needed.”
As Van Dam and his co-authors wrote, “[there is] neither one universally accepted technical definition of ‘mindfulness’ nor any broad agreement about detailed aspects of the underlying concept to which it refers.”

overcast• 8 years ago

A 16 hours fast is so easily achievable that many probably do it without even knowing. If you stop eating by 8PM, and skip breakfast till lunch at noon. That's a 16 hour fast. I've done that basically my entire adult life without even consciously thinking about it. These days I push it out to anywhere from 18-20 hours, and limit my calorie intake from 2pm-8pm. I've been slim my whole life, 175lbs at 6'1. Never get sick, last time I've been to the doctors was easily 20 years ago as a child. Haven't had an antibiotic since grade school. Cardio exercise daily, hiking mountains, no loss of energy.

rawland2• 8 years ago

My question in this article is: What were the properties of the participants in this study?

According to the paper these "eight overweight men with prediabetes [...] had a mean BMI of 32.2 ± 4.4 kg/m2" (page 3).

The metabolism of these people is quite different compared to a healthy human. These were sick people. And they received a strictly controlled and monitored diet according to the paper.

Paper mentioned in article: https://www.ncbi.nlm.nih.gov/pubmed/29754952

RobertRoberts3• 8 years ago

I have been experimenting with weight loss for the past year. My goal it total weight "control" _not_ loss. Anyone can lose weight, I want to never ever worry or think about it again.

Today I am at a low of 181.2lbs. I haven't been this weight for probably over 12 years.

Last summer I did a month of running 6 days a week (increased distance as I went) + 1 meal a day (strict). And lost .5-.6lbs a day in 30 days. I went from 202 to 187. I gained some of it back by December. I was fluxuating between 192-195.

Then I changed my tactic, did strength exercising for one month, got up to 198, didn't lose weight at all.

Current experiment: I changed two things -

1. I said "it's ok/fine/good to be hungry". I now naturally eat one meal a day, I eat when I want, but I don't fool myself. Sometime I eat only a couple bites of something to ease my stomach.

2. No exercise during this time at all. No running, lifting, pushups, nothing.

I have gone from 198 to 181 from last January to Oct, 2018. (17lbs) Not eating is what makes you lose weight. Being hungry is your body telling you it's eating fat. I even went to a wedding, gained 3 lbs in 3 days, and shed them again 3 days later. (obviously not all of it stuck on me in the first place)

After awhile you get used to being hungry, your diet matches your need and intake. Be hungry, control your weight, it's liberating. I never have to worry again the rest of my life how to manage my weight.

newnewpdro• 8 years ago

TL;DR: there's no need to feel hungry, you can graze on plain intact vegetables all day long. Use calisthenic exercise to keep you honest through feedback.

My experience going from 225lbs to 165lbs and keeping it there for over a decade now +-5lbs suggests there's no need to feel hungry at all, as long as I'm eating the right foods.

I didn't use any exercise, just removed sugars and most refined carbohydrates and processed foods in general. Most the food I eat by volume is raw organic produce. I can eat plain heads of lettuce all day long and I will not gain weight. I eat canned wild sardines, salmon, and sometimes tuna for protein and omega-3s, with the occasional (~weekly) meat binge.

Once my weight stabilized at 165, physical activity became a lot more appealing so I started hiking, running, doing hand stands, pushups, generally being more active and this has given me a more masculine physique but doesn't seem to play much part in maintaining my weight.

Sometimes I experiment by ceasing most physical activity for a week or two, and mostly what happens is I become less sexy looking, the weight is more or less the same with the uniform mostly-produce diet. My mood does deteriorate though.

When I deviate from the diet, usually for social reasons, eating meat more often or letting more refined carbs and generally processed foods in, my weight immediately goes up.

Another thing I've learned to appreciate about physical activity is the feedback it provides. Calisthenics like hand stands, pushups, pullups, all give direct feedback on your power:weight ratio. It's a lot more impactful to only be able to do 80 pushups when last week you were doing 100 every day, than see your weight increased by 10lbs on a bathroom scale. This feedback, for me, plays a more significant role in maintaining my weight through diet via exercise than any direct calorie burning.

RobertRoberts3• 8 years ago

It seems we arrived at the same place with similar tactics. Not sure where I will stop thinking about going down, and stay at a particular weight yet.

I find eating produce that just gets rid of hunger to be more unsatisfying that just being hungry.

I really really enjoy my dinner when I am hungry most of the day. My food is incredibly appealing and I have no concerns about how much I eat or what it is (generally speaking). So I guess the comparison here is "be hungry + eating whatever you want at the end of the day" vs "graze on vegetables all day".

My experiment is coming to a close soon though, as I am with you on the exercise benefits. My body is starting to get aches that I used to get before I started exercising. I've run regularly for years, but it didn't shed any weight unless I was perfectly diligent, which isn't something I could maintain just for weight loss.

Hence, I found the source to weight loss/control without extra effort, don't eat much. If I gain weight, eat less until it's gone. Exercise then is purely for strength and health, (and happiness as you have also found out) but not weight loss.

Happy to hear you got this under control in your life.

gremlinsinc13• 8 years ago

I'm 485. I had gastric sleeve surgery in 2012 at 650 (after losing 40 through liquid diet).

5 weeks ago I was 515. I started a fitness challenge at a CrossFit gym, I workout 4 days a week, I eat Keto, and I (sometimes) eat just one meal a day. I find it really hard, like extremely hard when doing IF to get all my protein in for the day.

I kid you not, because of my stomach size, the keto effects (lower hunger), and only having an hour or two window for food when I stick to IF completely I can't get more than 50 protein, and 600 calories.

This week, I've modified it to fit my body, I've added body fortress protein which 1 scoop in almond milk = 8 carbs, and 60 protein (my daily minimum). I eat this around 11 or noon. Then I try to have my 1 meal at 5pm. Is it IF? Not completely, but I feel for me it works a lot better.

I can probably still get only 600-800 calories a day; example: 2 burgers + 1/4th cup cheese and a dab of mayo and I'm stuffed to capacity, it takes an entire hour to finish this much food, but at my weight that's no biggie, the biggest thing is getting protein so my weight lifting at CrossFit has good results.

I'm no expert on physiology, so if anyone has tips to maximize my progress (I'm about losing more (fat) and gaining more(muscle) as fast as humanly possible).

Physically I feel like a million dollars, depression is mostly gone and anxiety as well. I'm a little obsessed on my diet/exercise regime, not sure that's bad. I started taking Vyvanse for ADHD so that also curbs appetite/hunger and has helped me focus more on my code/work. Last year I had major depression with dark thoughts, this year I feel like a different person, I'm also seeing a therapist for that stuff as of a few months ago.

squish78• 8 years ago

I have no advice, but applause and encouragement. Keep going and congrats on your progress so far. Don't stop or get complacent - you can be a motivator for other people and your progress can be a positive force for more people than just yourself

gremlinsinc13• 8 years ago

Thanks, I appreciate it. I feel great, I love Cross Fit -- the community has been VERY supportive and the box I go to is VERY good at modifying workouts -- I can't get down on the floor yet, or do lunges for example, but I still get my ass handed to me.

vlasev8• 8 years ago

There is some good evidence (both studies and anecdotal) that there is some muscle memory in the sense that it's easier to regain muscle that was lost than to build it in the first place. So even if you lose some muscle during this whole thing, you should be fine. You want your body to be in as much in ketosis as possible; it has a huge reserve after all.

I'm sure you've seen or heard of this case study of the Scottish man who fasted 382 days [pdf]! Of course, he did it under medical supervision. But I think it's an important case of what CAN be accomplished.

[pdf]: https://pmj.bmj.com/content/postgradmedj/49/569/203.full.pdf

gremlinsinc13• 8 years ago

Thanks, that's good to know... I think w/ the added 60g of protein per day --esp on workout days, I should be okay hopefully. Might lose some, but not a lot of muscle...and I think the ketosis will definitely help tone me up as well along the way.

mantenpanther• 8 years ago

Congrats! For the long run you might consider throwing in a day with multiple meals and significantly higher calories every now and then, sticking to whole foods for the most part. This might be good for your micronutrient intake (which I'm pretty sure does not cover the RDAs on 600-800kcals) and your metabolism, which might get wrecked in the long run otherwise.

I can recommend cronometer.com for tracking food, this might be a pain in the beginning, but gives you good insight on what your nutrient intake is. Helped me to create a diet with roughly balanced meals.

gremlinsinc13• 8 years ago

I track everything on MyFitnessPal currently. I also take a multi-vitamin and Vitamin D3 daily. I did think about doing some carb loading, and I think I might try it when I hit any stalls. So far things are going good though.

passing_by_and• 8 years ago

Dr. Dominic D'agostino & Dr. Layne Norton did a podcast on Joe Rogan recently.

https://www.youtube.com/watch?v=u93oh9kC-rU

In the course of the podcast, they discuss many areas of research that would be interesting to your question of maximizing your weight loss while maintaining health.

They also discuss what the research in these areas indicates works and what doesn't seem to matter. A lot to unpack but certainly helpful.

gremlinsinc13• 8 years ago

Thanks, I'll check it out.

logfromblammo2• 8 years ago

I'm not a nutritionist or broscientist, but of what I do know, what you are doing now is correct, and probably qualifies as a muscle-sparing fast.

You can eat more protein--likely in drinkable form due to your sleeve--to try to gain more muscle, or you could stay the course to lose the fat first. Since lean muscle mass increases your base metabolism, which increases your fat-burning rate, that's a complex equation that may require calculus to optimize, and your body can always just arbitrarily veto the mathematical results.

gremlinsinc13• 8 years ago

Thanks, I'll try the added protein shake + OMAD food-wise for a week or two and see how it works... I'm thinking it'll be better than just the OMAD with less protein/calories. If I need to, I could even adjust to 2 shakes/day and a meal in the evenings.. Maybe push my shakes to b/w 2/5pm and eat by 7, so I'm still doing a 6-8 hour feeding window.

lawn• 8 years ago

Because you've had that surgery and your stomach size maybe intermediate fasting isn't the best way for you in the end?

Instead a high fat low carb diet where you really minimize carb intake (and obviously avoid all things sugary). You can get the same keto effects if you follow this approach.

This way you can easily eat several times a day and get all protein and calories you need.

Of course you can mix and match IF with this as well.

I'm a little obsessed on my diet/exercise regime, not sure that's bad.

Be mindful. Obsessions always lie at the edge of turning bad.

Also if you've only done this 5 weeks it's easy to do too much too soon and if a time comes when you can't hold the same extreme tempo you risk a crash. This has happened to me many times. For example I've started a new training form and I train it a lot. But then I don't have the same drive like last week and a miss a single training. Then another one and suddenly I haven't trained for a month.

gremlinsinc13• 8 years ago

Thanks for the advice.. I think I'll keep trying this diet regime for a little bit, I like how I feel w/ it...

Definitely see your point w/ obsessions... I over analyze and think things. I also try to optimize everything as a developer that's just what I do lol..

I do have a fear that as winter comes I might slack off more on workouts, esp since my gym is 30 mins away (I live in podunkville,UT), so increment weather could affect my sojourn to the city to workout. I'm hoping I just let things go more, and it just becomes part of my life, at least till I hit my goals.

meiraleal• 8 years ago

Hey, have no references easy here, but you might not need that much proteins while losing weight. Fasted, your body breaks useless cells to get more protein when needed.

tgarv• 8 years ago

Just a heads up, most Body Fortress protein powders that I've seen are actually 60g per 2 scoops, not per scoop. Their marketing on the front is super misleading.

gremlinsinc13• 8 years ago

Fuck their marketing.. .I knew it was too good to be true.. double checked it earlier when I was putting it in myfitnesspal... I'll search around for a better deal.... I was using Dymatize which has more servings per bottle for 30g proteins... and a lot less carbs...

louprado2• 8 years ago

I am not an expert on psychology, but your goal "losing more (fat) and gaining more(muscle) as fast as humanly possible", might be detrimental to your success.

It probably took decades to get to your current body weight. Should it not then take at least 5 years to get back to your target weight ? True the caloric math shows you could probably get to 250lbs in a year with a 600-800 a day diet. But can any human actually stick with that diet for more than a month ? If not, you would be better eating 1600-1800 a day if you could stick with it for a year.

As an aside, at times I wonder if our obesity epidemic is in part related to an ever increasing target/acceptable weight. When I was a kid, if you could pinch an inch, you were overweight (I stop drinking calories if I pass the threshold). Even my childhood bathroom scale maxed out at 250 which implied that 250 must be extreme morbid obesity.

I know this is personal, but when you were young did you ever have such thresholds (weight, mobility, etc.) in mind ? Or did it just sneak up on you and by then you were in gaining weight at a surprising rate beyond your control ? No worries if you are too busy to respond. I wish you the best!

gremlinsinc13• 8 years ago

I don't think it took decades... I was 410 at 14... that's a decade/half maybe... but I was always obese...since birth practically. (80 @ 6, 300 @11, etc..)

ccmonnett3• 8 years ago

My experience with time-restricted eating has been that, regardless of the benefits of the fasting itself (which FWIW I do believe in), it has brought one significant change into my life: caring much more about the nutrition of each meal I eat.

Before I began fasting, I found myself saying things like, "Well, this isn't great for me, but it'll be filling for a few hours and then I'll eat something else." With IF that is not an option, and it forced me to more carefully consider whether I was providing my body with the proper fuel for the next X hours.

Similarly, coming out of the fast, I was much more likely to eat nutritionally-valuable foods because I knew that whatever I put in my body it would immediately consume for fuel and I wanted to give it something valuable.

That in itself has led me to rave about IF to anyone who is interested enough to listen. I recommend at least an experiment with it to experience that consideration of nutrition, because I think that will stay with you whether you stick with IF or not.

matachuan• 8 years ago

Never thought I'd see this on here...There is no need for all the complications like IF, etc. This game is only about your caloric deficient and surplus.

jcoffland3• 8 years ago

Many people don't like this but it all boils down to calories in calories out. All human bodies work pretty much the same way with some slight variances due to disease and genetics. Fasting works because it restricts your overall intake.

thebeefytaco8• 8 years ago

Many people don't like this but it all boils down to calories in calories out.

Not true. Calories are a very crude metric of metabolic energy.

Wood (and anything else that burns) has a bunch of calories, yet we cannot process it as energy.

jcoffland3• 8 years ago

Undigested wood would come out your butt, hopefully. So it's still calories in, calories out.

Tharkun2• 8 years ago

Many people don't get this, but calories aren't a very reliable measure of available energy. Measuring the caloric content of food is a pretty weird process, and is some kind of "one size fits all" measure of energy which we might be able to extract. The digestive system is not an engine, where you put in fuel, add oxygen, combust and use the energy. The digestive system is more like a mining operation which extracts coal from the bedrock that is your food, and which then throws it over the wall where billions of consumers burn the coal for energy.

That process isn't anywhere near 100% efficient. There is a huge amount of complexity in how food is digested and broken down into protein/sugars/fats. Some people can't even break down certain foods. Even more complexity in how those macronutrients are then dealt with.

Sure, in any system energy in == energy out. But without a way of reliably measuring how much available energy there really is in food for a specific body, there's really no way you can say "calories in, calories out".

jcoffland3• 8 years ago

It's a simple matter of measuring the calorie content of the food going in minus that of the waste going out. There are many things that contain calories that humans don't digest well but the things we tend to eat have pretty consistent calorie digestion to waste ratios, regardless of the eater. Beliefs to the contrary are mostly driven by the food fad industry.

jordache• 8 years ago

It was likely the successful efforts of snack-food companies advertising to dietitians, and doctors, clueless about nutrition at the best of times, who simply went along for the ride.

How did he make that determination? Oh I see "likely"

tw1010• 8 years ago

My main qualm with intermittent fasting is that it makes me hungry, which depletes my will-power budget for the day (which prevents me from being productive later in the day). Is there any diet that works better than IF (or just as well), given the constraint that it also needs to minimize use of your daily self-dicipline resevoire?

martin-adams• 8 years ago

I find that happens when I also have carbs during my eating window. By reducing carbs and increasing fat, I’ve noticed less hunger feelings and more mental clarity.

sys_64738• 8 years ago

I fast for 18 hours every day and only eat during a six hour window. I've done this for 5 months now and lost about 15 pounds.

louprado2• 8 years ago

Given that poor sleep quality exacerbates insulin resistance, it is possible that by not eating late into the day, the research subjects in the article's fasting study may have also lost weight because their sleep improved.[1]

Personally if I eat dinner after 5PM, I have trouble sleeping.

[1] https://www.ncbi.nlm.nih.gov/pubmed/21950773

mysterypie2• 8 years ago

The volume of ever-changing and contradictory advice about dieting is maddening. The only dieting advice I truly accept these days is the First Law of Thermodynamics. In context of dieting, you could state this as, eat less (calories) or exercise more (joules) or both, and you will lose weight. Absolutely guaranteed by a fundamental law of physics. Yes, it's very hard to follow this rule, but for me at least a simple rule that is guaranteed to work is much better that complex rules and theories that inevitably turn out to be nuanced, dependent on particular genetics or environment, or plain wrong.

ionforce2• 8 years ago

I think everyone knows that "works" on paper. But people are looking for solutions that fit their lifestyle, including human imperfections like the lack of willpower.

mysterypie2• 8 years ago

I think everyone knows that "works" on paper.

You'd think so, but people with science or math degrees have said, it doesn't work for me, even though I point out that we're talking about laws of physics, not about willpower. Never mind the average person. The average person will not agree that "eat less, exercise more, guarantees weight loss".

Regarding your other point, I know that everyone is looking for a shortcut, trick, or something that works for them. I'm saying that with the insane volume of unreliable studies and advice, it's simpler to ignore it all and try one rule that will work.

mark_l_watson• 8 years ago

I am participating right now in one of these studies (Stanford University).

Amazingly, you really don’t get hungry at night after a breaking in period. I eat between 9am and 6pm, so not quite the same time period as in the article.

mythrwy• 8 years ago

A good cleanout a few times a year is great, but skipping meals and walking around hungry on a regular basis doesn't work for me at all.

3 reasonable sized meals a day with maybe a light snack is just right. No heavy meals, not too much carbs (but not no carbs either). Plenty of vegetables and fruit and protein. Regularly, in small amounts through the day. Keeps me at the right weight, blood sugar not spiked, not off.

Being hungry I have trouble focusing. And mood gets off. I make worse decisions.

Not sure why this fad is so promoted lately, maybe it works for some people but not me and "our ancestors starved" isn't really a good reason to torture oneself for no discernible reason in my opinion.

octygen• 8 years ago

Am interesting read. IF is supported by much science and I even studied it in a Coursera course on brain hacking. Along with Mediterranean diet and Keto, it's great for the brain and body apparently.

That said, the best advice my Cirque-coach gave me: match food intake with exercise in a given day. So if do a killer workout today, intermittent fasting is not going to give me enough fuel. But if I sit around in meetings/writing 6AM-10PM, fasting for 16h and eating in 8h of that day could work as it'll simply be lessening how much you one eats.

Jason Fung explains why intermittent fasting diets work

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