I'm in the same boat. I don't stick to it extremely strictly, and the window moves around a bit but generally I follow 16/8 too and haven't noticed much of change in body fat (but I don't carry much anyway).

The reason I stuck with it was that, as someone who wasn't ever a breakfast person either, I don't have the stomach discomfort / bloating anymore which a carb-heavy breakfast would give me.

For me the nicest part about IF becoming trendy is that I don't feel that slight pang of guilt anymore which I used to feel when skipping breakfast.

Everyone is different but I was formerly obese and doing a 7 hour fasting window in the morning (7am-2pm) I dropped into a healthy BMI shockingly fast.

I ate meat, processed sugar, and dairy throughout. In the past I tried cutting those things out (except meat) and I struggled with weight loss.

The one other factor that probably played a role is that I cut out restaurants.

Skipping breakfast is so damn effective because in the morning blood-cortisol levels are quite high, making it easier for your body to store so energy, energy we provide by breakfast but generally don't even need at that time.

I believe the research shows that skipping dinner is much more effective — in fact, there is debate as to whether skipping breakfast is even beneficial (anecdotally I would say it is).

I wish I understood the mechanism better, though.

> The one other factor that probably played a role is that I cut out restaurants.

You would be shocked how many calories restaurant food has (usually >1k calories in a single dish -- no matter what kind of restaurant -- and probably more in the US). Personally, I would've assumed this is the more likely primary factor for your weight loss (combined with the fact you probably eat less food overall because you only have two meals when doing IF). You could try going to restaurants again for a few weeks and see if you start gaining weight again.

But, if it works for you -- it works for you.

To be clear, I have tried going to restaurants both before and after I lost a majority of my weight and I still lost weight but not as rapidly.

It appears as though cutting out restaurants made a difference but it’s also easy to underestimate the power of having a morning-based feeding window. People are more insulin sensitive in the morning and have reduced appetite (hence everyone saying “IF is easy, it’s so easy to skip breakfast”).

Definitely. Coming home after traveling to the US for more than few days means constant hunger and snack cravings for a week or so. The last few times I’ve been trying to limit the unnecessary sugars from sodas and other sugar rich food since you get so much more sugar than in Europe in the regular restaurant food.

I always tell my wife that the easiest way to get healthy is to become poor. No more restaurants and you're golden.

Jokes aside, I feel we all underestimate how much eating out and/or socially forces you to eat more than necessary. Personally when we're cooking, we rarely go overboard. When you eat out, it's so easy to eat more than what you need.

No offence taken :-)

I'm not a professional, and I didn't track anything except my body measurements and weight during this process so I don't know exactly where all the results came from. I wasn't chugging bottles of Coca-Cola, but I was having processed sugar in my multiple cups of coffee every day.

As for calorie counting, my research indicated that calorie counting is a myth (see The Obesity Code by Dr. Jason Fung). Certainly, I always struggled with a calorie-restricted diet, so I knew that if I always felt hungry, anything I did wouldn't work. I know it sounds odd but during the 16 hours I am fasting, I just don't feel that hungry. If I feel a little hungry I just drink some water and I feel fine.

I think the key was satisfying the ghrelin by eating as much as I liked during my 8-hour feeding window. I know it sounds crazy that you can eat as much as you like and still loose weight but it happened.

> my research indicated that calorie counting is a myth

Given that calorie counting (or rather, being in a caloric deficit) emphatically does work[1] (it's roughly just a matter of thermodynamics), I would (respectfully) argue that your research was insufficient.

It is true that the vast majority of people underestimate their calorie input, and there are some special cases (such as diabetics) where calorie counting doesn't give you the results you expect (insulin resistance increases the amount of energy required to "burn" a certain amount of fat because insulin is used in fat expenditure). A disturbing amount of weight-loss studies depend on subjects to self-report the amount of calories consumed -- which almost always invalidates the conclusion (people always underestimate their calorie consumption, doubly so when they've just started a diet!).

However, for the vast majority of people, the standard formulas for total daily energy expenditure[2] are more than accurate enough for accurate weight loss (especially for people who are >15% body fat -- once you get really lean there are other considerations when trying to reduce body fat). They definitely aren't perfect, but they're usually accurate to around ~5-10% (more than enough to get a good idea of how many calories you should be consuming, and how much of a deficit you need to be in in order to lose a certain amount of fat at a certain rate).

> Certainly, I always struggled with a calorie-restricted diet, so I knew that if I always felt hungry, anything I did wouldn't work.

Did you change what kinds of food you ate when eating with caloric restrictions? Usually you want to eat very low-caloric-density foods like broccoli (your body's "fullness" reaction is determined by the volume of food you eat, not the nutritional content). A common mistake is that people will try to eat the same types of food (high-caloric-density), just less of it -- this is a recipe for disaster because it will lead to inevitable hunger tautologically (not to mention most high-caloric-density food has lots of sugar which triggers an insulin response -- causing more hunger after you've eaten it).

The primary reason why people lose weight when doing intermittent fasting is because they consume less calories as a result (you would have to actively stuff your face to get the same amount of calories in 8 hours). Have you tried counting calories now that you intermittently fast, and compared it to how many calories you ate beforehand? You might be surprised to find that's where the real change lies.

All of that being said, feel free to do whatever works for you. Personally, I found it easier to count calories and eat higher-density food. Then again, I usually skip breakfast so you could argue that I also intermittently fast.

> I know it sounds crazy that you can eat as much as you like and still loose weight but it happened.

I very strongly doubt this is true, purely due to thermodynamics. If you ate 10k calories every day (with intermittent fasting) you would gain weight (if you don't believe me, try it for a month and see what happens -- you should gain a few kilos a week depending on your existing weight). I would guess it's more likely that you simply felt that you ate more (but actually started eating less). Do you weigh your portions of food (most people are awful at estimating even how much mass of food they eat, let alone the caloric content)?

[1]: https://www.healthline.com/nutrition/does-calorie-counting-w... [This goes through common tropes in papers which are often misunderstood to say that calorie counting doesn't work.] [2]: https://tdeecalculator.net/

It sounds like you know a lot more about this stuff than me. It is my fault in so much as I should have used more precise language. What I meant by 'calorie counting is a myth' is that a calorie reduction diet is a myth. Sorry for the confusion. Also, I admit, I could be wrong. I'm going off of the research I have done.

That said, there is a lot of stuff happening in our body with regards to our food intake that I had no idea about. Insulin, ghrelin, leptin, and of course, testosterone for a man, is extremely important. Even limiting xenoestrogens as a man is extremely important.

Also, people seem to forget somehow that your body can excrete calories.

I agree with you about the problem of "people will try to eat the same types of food (high-caloric-density), just less of it". In the past, I tried a vegetarian, calorie-restricted diet, and I just felt hungry all the time. It wasn't a one for one diet to what I eat now, but it about the same.

In terms of why intermittent fasting works, I don't know for sure, but from what I have read, your body's metabolism doesn't crash because your feeding window controls the ghrelin in your system. With your metabolism maintained, and by only drinking water during the 16-hour fast period, your body is forced to consume your fat stores for energy.

Having said all that, you could be right... perhaps I just consumed fewer calories as the plant-based diet was just less calorie-dense. The volume of food may have made it feel like I was eating more when I wasn't. Honestly, I just don't know for sure.

Calorie counting works, when someone else is controlling your food supply.

When I control my food supply, my hunger will almost always override the cold math of the calories.

It's a bit like how abstinence can prevent pregnancies, so you don't need condoms or pills. It's of course true in a technical sense, but real world people aren't strong enough to remain abstinent.

This was my experience until I started using a fitbit to get an accurate daily burn count. It showed that I was setting my calorie count way too low, hence the hunger issue. If I eat the fitbit daily burn minus 500 calories I lose 1 lb a week with no hunger issues.

> When I control my food supply, my hunger will almost always override the cold math of the calories.

That's a case of your hunger causing you to eat more calories, not a case of your hunger causing you to gain more weight from the same calories. The math still works just fine if you count the calories that your plan says you shouldn't have eaten. It's the plan that isn't working for you, not the math.

You're stating the obvious.

One would hope, but there are plenty of people who double-down on the obviously-wrong interpretations of ambiguities such as in your comment. People are surprisingly willing to misattribute the causes of of their diet's success or failure.

Well, apparently I'm not "people" in that sense.

Unfortunately, every lifestyle change requires hard work. You can't learn to dance or play an instrument without putting in the hours. Same thing applies to losing weight and getting healthy.

Sure, there are "tricks" (such as eating lots more low-calorie-dense food such as broccoli or cucumbers to quell hunger pangs) but those are just tools that still require hard work to apply.

The keto diet takes the opposite approach. Very calorie dense fatty foods turn out to take a long time to "turn around" to where you get hungry again.

A lot of people lose weight doing that without the hard work, aside from abstaining from all your favorite sugary foods. But there is plenty of delicious fat & protein food.

It was my understanding the point of the keto diet was to trigger ketosis -- in which your body starts using fat reserves more readily.

But yes, one of the driving factors of "hunger" (when people eat high-sugar foods) is the insulin spike and associated cravings. Cutting out all carbs gets rid of sugar, which results in no more insulin-spike-driven "hunger". But really, all you needed to do to do that was to reduce your sugar intake. It's also quite hard (though definitely not impossible) to load up on lots of calories without carbs. Most high-calorie food is also high in carbs, because refined carbohydrates are ridiculously calorie dense and it's hard to find something that's easy to eat lots of that matches it. You can't really eat a whole tub of butter, but you can eat a whole loaf of bread or plate of pasta.

> aside from abstaining from all your favorite sugary foods

That is the hard work I was referring to. While it might be a slog when you start out, exercise can be surprisingly addictive thanks to the rush of endorphins you get. But you don't need to exercise to lose weight, nor is exercise alone sufficient -- you can't out-exercise a bad diet.

I'm no keto expert, but I think you can do it in a lighter form that doesn't reach the ketosis trigger point, and still get a lot of benefits. If that should rightfully be called a "keto diet" is a linguistic question i don't worry much about.

Back when I switched to the paleo diet some 10 years ago, I was ready for a huge fight with my cravings as I gave up all the sugar and grains etc. But nothing of the kind happened. I just started eating other food that I liked just as much, and felt fine. Lost 25 pounds over 6-9 months.

Maybe it was unusually easy for me. And paleo does allow some carbs, though I definitely cut down a lot.

Agree 100% about your exercise point!

We have been brainwashed into thinking that "cravings" are psychological. Ketosis shows that carb cravings are physiological.

Energy in, energy out. You lost weight because your ate less than you burned, full stop. IF is just a way to curb hunger until later in the day, so you effectively take in less calories than you normally would.

Why do you believe the calorie in calorie out hypothesis is correct? Do people digest all food equally? If I eat 4,000 calories of olive oil, will I metabolize every last bit of it without waste? Obviously not. But what about different ratios of fats and carbs. After to failing to lose much weight on a low fat diet I had resounding success on a low carb diet, and I can say without a doubt I consumed far more calories on the low carb diet.

> If I eat 4,000 calories of olive oil, will I metabolize every last bit of it without waste? Obviously not.

And if you were 200 meters tall or 5000 years old, the TDEE equations also wouldn't apply to you correctly. Most calorie counting studies are done with intake of "normal" foods, not just pure olive oil. In those circumstances, for the most part, calorie counting works well enough for you to lose weight. Yes, the TDEE equations aren't perfect (and neither are nutritional information labels) but they're all within enough of an error margin for you to be able to comfortably lose a kilo every 2 weeks without breaking a sweat.

It is also true that you should tailor your diet not just for weight loss but also for general health (so cutting calories isn't enough, you should also change your eating habits) -- but weight loss is (for the most part, and the vast majority of people) just a matter of TDEE and counting calories.

> After to failing to lose much weight on a low fat diet I had resounding success on a low carb diet, and I can say without a doubt I consumed far more calories on the low carb diet.

Did you measure the changes in your fat weight? Low-carb diets can cause additional weight loss, which is not actually fat loss because some carbs are stored elsewhere in your body[1,2]. Now, that doesn't mean you didn't lose more weight. It just means that you didn't lose more fat. Whether or not that matters to you is a different question.

[1]: https://www.healthline.com/nutrition/does-calorie-counting-w... [subsection 3] [2]: https://www.ncbi.nlm.nih.gov/pubmed/1615908

I lost 43lbs so obviously it was nearly all fat that I lost. How many people losing drastic amounts of weight on a low carb diet, while consuming more calories than before, would it take to convince you that counting calories is seriously flawed?

Why is it obvious that 4000 calories of olive oil is not metabolized without waste? Please provide sources.

> Please provide sources.

This is sometimes even lazier than not providing sources.

There's always waste. If not I'd been a lot fatter than I am because at times I ate much more calories than I burned.

What is true is that a steady calorie deficit will cause weight loss in the long run, and can to some degree be calculated and predicted.

Calculating the effects of calorie surplus on the other hand is a bit harder.

BTW: https://www.google.no/search?&q=absorbtion+and+metabolism+of...

Respectfully you are coming from a certain frame. There is always the possibility that other frames exist that may be a more accurate representation of reality. If you are open, check out The Obesity Code by Dr. Jason Fung.

Conservation of energy still applies.

Weight management has a strong mental component, but only because of the current abundance of calories.

PS: And yes we are included poop calories. That’s how olestra and artificial sweeteners work.

Energy in/out, at least in the sense most people and your grandparent refer to, can be wrong without violating conservation of energy. E.g. if you poop out food from which not all calories have been used.

See, I wouldn't define pooped out unused food as being "in". If you want, you can define it as "in", but then you need to also include the pooped out energy in the "out" column.

That’s really not how food calories are defined. https://en.m.wikipedia.org/wiki/Atwater_system

Now, a lot of simplification goes on and it’s true food labels are based on heathy digestion. But, that has little to do with the actual definition.

PS: I think this goes back to how the description of how Calorimeter’s are used. Yes, they give a value from burning food, but that’s not the only number being considered.

The solution to this issue is not to start claiming things in violation of thermodynamics. Instead you should call attention to the fact that nutrition labels do not always accurately count the number of bioavailable calories ("calories in"), and that unusual circumstances can drastically change an individual's ability to extract energy from their diet. Rejecting "calories in = calories out" is a distraction from the real challenges, and has the side effect of making you sound much less scientifically credible.

Edit: see this comment for an example of reasonable discussion that doesn't oversimplify to the point of contradicting basic science: https://news.ycombinator.com/item?id=20860678

The thermodynamics matter only as much as they are a tautology (which means: not at all), or as an upper bound.

Thermodynamics predict that you'd be better off drinking gasoline (12kcal/gr > fat's 9kcal/gr), and just as well eating wood chips (a carbohydrage) -- even though you get zero energy from either.

"But we're not using calorimeter data, we're using atwater factors"; Well, those actually DO vary from person to person, IIRC as much as 50%; and other things also matter (e.g., adding activated carbon to your food will result in less energy extracted in general; using Ally would result in less energy extracted from fat).

And that's just for the "calories in" part; metabolic rate can also vary as much as 80% along time and between people, depending on muscle volume, or other random, less understood factors - so without a proper measurement chamber you don't know the "calories out" either.

The food labels and general activity tables serve as a good general approximation that describes probably 80% of the public quite well. But invoking thermodynamics (except as an upper bound for calories in) is not justified by our current understanding of metabolism.

> But invoking thermodynamics (except as an upper bound for calories in) is not justified by our current understanding of metabolism.

The problem is when people claim that they can lose weight without running a calorie deficit. This is what's obviously wrong, and it is completely fair to invoke thermodynamics as a way to immediately and soundly refute such claims. When someone claims to have anecdotal evidence of losing weight while not running a calorie deficit, the error is not with the "calories in = calories out" equation but with their poor accounting of where the calories are going.

In my experience, people who promote their pet dieting theories (especially ones that promise dramatic weight loss without requiring exercise) using thermodynamically impossible claims are far more prevalent than people who mean lab calorimeter data when they talk about the calorie content of their food. Your comments about gasoline and wood chips are an insulting straw man, because nobody is ever referring to those numbers in a casual context. They're talking about the calorie numbers that can be found on nutrition labels, and those are meant to approximate metabolisable energy, not heat of combustion.

> The problem is when people claim that they can lose weight without running a calorie deficit.

Of course people can lose weight without running a calorie deficit. It's a commonplace experience nowadays, and absolutely trivial to demonstrate. You can test if for yourself if you are even slightly interested in checking the validity of your theories.

The death of the ridiculous thermodynamic model of human nutrition can't come soon enough.

I agree about the prevalence of pet theory, but my example wasn’t a strawman.

Your thermodynamic argument involves values that you take on faith (Atwater factors) which have been shown to have 50% variance, and values like BMR that also have 50% variance. As a result, invoking thermodynamic impossibility is not justified.

I agree with the gist of what you are saying - but not with the validity of the thermodynamic reasoning as proof.

> Your thermodynamic argument involves values that you take on faith (Atwater factors) which have been shown to have 50% variance, and values like BMR that also have 50% variance.

No, it really doesn't. Just look at the sibling comment that claims once again that it's possible to lose weight without a calorie deficit. That statement is wrong no matter how good or bad an approximation you have of what fraction of the heat of combustion is metabolisable.

If someone believes that they are losing weight while eating a diet whose nutrition labels indicate a much higher calorie count than their estimated calorie expenditures, then it's obviously wrong for them to claim that they are not running a calorie deficit. Instead, the reasonable and scientifically valid claim they could make would be that they are metabolising a much smaller portion of that diet than a normal person would, and thus they are running a calorie deficit because lots of calories pass through them unabsorbed.

Yes. Thermodynamic principles are tautological in the sense you just described and arguing against them isn’t helpful.

However, as the GP claimed the “gasoline is a strawman”, and “that’s not what people refer to when counting calories”; these two cannot live together with a thermodynamic argument in any useful sense, because it amounts to “well, if your food labels say a number higher than your exercise machine and BMR, the your numbers are wrong for reasons I cannot point to”, that’s about as helpful as a religious argument.

You can lose weight easily without caloric deficit in any sense - water weight (limited amount of course). There are several other ways in which the body loses fat - e.g. through the skin and scalp (negligible amount for most people, but not all people).

Invoking thermodynamics as an end-all be—all argument is dishonest even if it is a useful approximation.

It’s very useful when studying diets. There are meaningful differences between undigested calories, excreted calories in urine or Methane, and increased metabolism. For example increased metabolism resulted in extra body heat which needs to be removed.

Water weight is similarly important and still conserved in terms of energy. It might seem meaningless to you, but an athlete who wants to stay at absolute peak performance may want a more accurate picture of what’s going on.

It's the CICO crowd who are ignoring basic science when they claim the human body will perfectly digest food.

Across time a person's ability to extract calories from food changes because their gut flora changes.

> It's the CICO crowd who are ignoring basic science when they claim the human body will perfectly digest food.

That's not at all what anyone is claiming when they say you need to run a calorie deficit to lose weight.

>> Conservation of energy still applies.

Of course, but in this case we can only measure energy intake, and only semi-accurately (not everybody metabolizes every food 100% efficiently).

The body is known for up-regulating and down-regulating energy expenditure based on a wide variety of factors, especially blood sugar level. So what you eat matters as much as how much you eat.

'Calories in, calories out' has been pretty widely debunked - at best it's part of the story. More important is meal timing (i.e. fasting), resting insulin levels, the source of those calories, etc.

> 'Calories in, calories out' has been pretty widely debunked

Could you provide some sources? This is the first time I'm hearing of this.

Not OP, but the general logic behind "calories in = calories out" is obviously fine. However, just knowing this doesn't really tell you anything about the best way to go about decreasing "calories in" or increasing "calories out" in a way that will result in meaningful fat loss and improved health. For example, it is plausible that someone could reduce "calories in" by eating less and their body could make up the difference by reducing "calories out" via lower BMR instead of having "calories out" remain constant with the difference being made up by burning fat stores. Maybe some fat loss will occur initially at the expense of being more tired and hungry but this change eventually becomes unsustainable/unhealthy if they aren't eating the right foods.

On the flipside, you can increase calories out by exercising but you could end up starving and/or exhausted as your body tries to compensate for the increased activity, depending on what is going on in your body hormonally. Or you just have no energy to spare for exercise as it is right now, and have a very hard time getting in to an exercise routine. All this is to say that "calories in = calories out" is all fine, but these variables are not independent. Having some knowledge of how and when the human body burns fat and when it stores fat goes a long way in coming up with a strategy to lose weight. This is where these trends of low carb diets and (intermittent) fasting have originated from.

You nerd to get a new Dr. or nutritionist if that's what they told you. If you just got that from rando internet bro science you should talk to a Dr. or nutritionist or try to back your statement up with some clinical research.

No, it has not. It is very well supported by studies.

Different energy sources metabolize differently, so energy in, energy out is technically correct, but not very useful in real life. Additionally, as others have mentioned, there are other factors which affect how the energy in is handled or metabolized besides just the pure energy you consume.

This is misinformation that ignores the findings on gut biomes (and how they affect both our body and brain), how different foods affect insulin sensitivity, psychology, and other factors like effort and convenience. IF isn't "just" a way to curb hunger.

You didn't contradict the person you responded to, if you consider "calorie counting is a myth" to mean that calorie counting doesn't help you lose weight.

The frame can be correct, but inefficient as a mental model.

High-level languages may be "just" a way to run the right assembly code...but I still prefer them over assembler.

it's probably slightly coupled though, avoiding cravings put your mind into a different consumption mode. When you didn't eat for that long, you won't go for a chocolate bar, you'll aim at actual proteins.