So, in other words, that means that, even if "calories in, calories out" might be trivially true, which I would still imagine it is because thermodynamics, it's not actually useful as weight loss advice?

Because the human body is not a passive system. It has all sorts of autonomic processes designed to control both calories in and calories out, and they have a tendency to subvert and/or counteract anything you're consciously doing to adjust your overall energy intake and expenditure.

I'm obviously no health scientist, but, just thinking out loud, that seems pretty believable? Partially because, of course, nothing's ever that simple. But also, speaking purely speculatively, I can't imagine my body responds to me consuming a 1,500 calorie holiday meal by immediately producing three more pounds of fat tissue, and then making it disappear the very next day. So, even from that, it seems implausible that the body's arsenal of ways to deal with simple day-to-day and hour-to-hour variation in energy consumption has to go way beyond simply growing and consuming new tissue. Which is what it would seem to imply if useful weight loss advice really could be as simple as "calories in, calories out."

Elsewhere I linked an article on the variability of the brain's calorie consumption, and one of the sources it cited was a table of calorie expenditure per hour across several activity types. Including things like reading a book or preparing a meal. It wasn't nearly detailed enough to know for sure, but, based on what I saw from a cursory glance, it seemed at least plausible that your body could completely counteract several hundred calories' worth of reduced food consumption by, say, simply making you unconsciously be a little bit less fidgety throughout the day.

I would still suggest that "calories in, calories out" is still solid weight loss advice. There are two major confounding issues that might make it appear incorrect. The first is that out is variable, and the second is that some parts of the system are noisy. The solution to both is to try to measure accurately and frequently. The best things one can do to achieve this are daily weigh-ins at approximately the same time and trying to account for the bulk of one's caloric and macronutrient intake.

Is it, though? To me, part of what qualifies advice as solid is that it has to help people who take it achieve the desired outcome. My understanding is that there's a staggering lack of evidence that that is the case. And not for lack of people looking for it.

Which leaves me thinking that this is an idea whose memetic fitness far exceeds its practical value.

The elephant in the room here is the article itself. The basic premise here is that internal bodily processes can increase your energy expenditure by as much as several thousand calories over the course of the day, even when you're being physically sedentary. And if it can autonomically increase the burn rate, surely it can also autonomically decrease it.

I've certainly noticed that I have a more difficult time thinking clearly on days when I'm not eating as much as usual. I wouldn't be surprised if a similar thing happens if I take a long bike ride without eating any extra food. Though this isn't something I've paid attention to in the past, so I suppose I don't really know. But still, if the body increases calorie expenditure during periods of higher brain activity, then it is certainly just as capable of reducing brain activity in response to a reduction in readily available energy.

I certainly can't speak for you, but it has worked quite well for me as I described it, for both gaining and losing weight as needed. I sympathize with people who do a poor job of measuring, either through inconsistency or incorrect calculation, but we don't blame the game of chess for people who play it poorly or suggest that they are evidence that it does not provide value to those who do, do we?

I can't speak for you, either. But I'm not talking about individuals' stories here. That's one of those, "the plural of anecdotes is not data," situations. When it comes down to empirical data, it seems to be a bit like the situation with acupuncture: it works just well enough to ensure that there's always someone who will show up and say, "It worked for me!" when the subject of its poor performance in clinical trials comes up, but not well enough to demonstrate practical efficacy under scientific scrutiny.

Perhaps that really is because basically nobody is assiduous enough about their calorie counting to make it work. But, even if we take that as true for the sake of argument, insofar as the point I'm making is, "This advice has a terrible track record of helping people lose weight," it doesn't work as a counter-argument. Quite the opposite. It works as a supporting argument, by showing one possible reason for why it has such a terrible track record.

I also don't think that it has legs as an idea for how best to reduce the obesity rate. If it were really that easy, then you would expect the population's average BMI to be much higher back when people didn't have the means to effectively calorie count, and it would steadily go down as the means to calorie count more accurately become more widely available. Instead we see that the opposite is true.

Absolutely. I was weighting before and after sleep every day, and results had fluctuations up to .5 kg, but after two weeks the trend was easily visible.

Just as a general comment: weight alone is a shit measurement for overall health. You really want to know your body fat percentage, at a minimum.

I'm curious if you have a simple, accurate way to measure body fat percentage at home. If you do, would you please share it with the rest of the world? It's probably worth quite a bit.

This study says that women feel hunger more strongly than men due to physical differences in the brain. True or not, the idea that some people just feel more hunger for the same amount of calorie deficit could explain a lot.

Also, "calories in, calories out" is the second thought-terminating cliche[1] I've encountered today!

[0] https://www.bnl.gov/newsroom/news.php?a=110876 [1] https://en.wikipedia.org/wiki/Thought-terminating_clich%C3%A...

One self-regulating thing really does exist. If you are already overweight, the body can self-regulate itself, by extracting fewer calories from processing from eaten food. You can take in food for 3000kcal, but the already overweight body can take in just 2700.

This has only one effect: when a person decides to lose weight, it'll make it harder for him, because eating slightly less than will have no effect at all, and the body is already used to eating a lot, so reduction in incoming food brings immediate discomfort.

But the opposite direction is rock solid: if you don't eat enough to compensate your passive calorie burn, you will not gain weight ever.

Anyway, this method helped me to go from 96 kg to 83 kg in 10 weeks, taking on average 1750..1900 kcal per day. For me it turned out pretty easy. First two weeks were the hardest, and I took in up to 2000 kcal, gradually bringing it lower.

> You body has its own idea of your weight set-point, and tries to keep your body mass in that range.

There's not much scientific evidence for "set point weight" or "starvation mode" or other similar concepts. People regain weight after dieting most likely because they go back to their old eating habits rather than making a lasting diet changes. But it's more convenient to blame their body stubbornness than their own lack of discipline.

Is there data to back up an individual 'set-point'? People think differently, so I can only speak to myself:

If I was heavier than desired, and I noticed my body was gaining weight while I am suppressing caloric intake, I would reduce intake even further. Call the bluff.

Of course, easier said than done. It's perhaps a masochistic mindset, forcing yourself to feel hunger, and obstinately refusing to give in. Since I was young, my conscious response to hunger seems different than many. I can easily ignore it for hours, if I am focused on something interesting. Hunger is an annoyance I typically ignore. The body screams "Wahh, I'm hungry! I'm going to make you feel bad until I eat!" and my internal voice says "Go right ahead. Suck it up, you're fine. I'm having too much fun to tend to you. Maybe you get something in a few hours."

If anything, I probably don't eat 'enough'. But I don't try to eat less. I eat whatever I want whenever I want. I am very happy with my weight. I eat a wide variety of nutritious food. But ultimately it's just annoying that we have to eat at all.

Basically what you allude to is the metabolic rate. Your body has a metabolic rate, and if for whatever reason this gets out of whack - eating unhealthy, gaining a lot of weight, it becomes very hard to come back to baseline. Hence the yo-you effect of most diets.