It's genetics. I think it's called the set point theory. You're genetically programmed to keep a certain body fat percentage. Anything below (or above) that set point and you're body will regulate your appetite with hormones. You can manipulate this set point with things like diet or exercise, but there is only so much you can do. If you're genetically programmed to keep a body fat percentage of 25% for example you're not gonna have a lot of fun staying below 15%.
I suspect something like that is going on. It is pretty clear to me that there is a strong genetic component. We know the hunger system is very complicated. It's the reason we still don't have a weight loss pill. If you decrease hunger along one channel, the other channels ramp up to compensate.
But there also may be other components that we can do something about. For example, perhaps the bacteria in my gut are causing half of my hunger, insisting that I eat bread (because they want it, not I). And if I starve them out on a zero carb diet, I can break free of the excess hunger.
I don't think it's just genetics, or genetics are rapidly changing in the last 100 years.
Personally I think it's some combination of gut biome, all than not messed up childhood eating habits (I've been taught to eat till stuffed, not so great in combination with my next point) , and way too calorie heavy (processed) food (it's not a challenge to find food where a quarter package is a healthy amount, way more challenging to find food where they food for a full package) not too mention it's made to keep you eating (so more is sold, sigh) . I'm always surprised people claiming not to have cravings whatever (even when the stuff is put in front of them), or be satiated by eating what for me is half a meal (even when I maintained a normal weight) .
Regardless eat less and try harder are hard to keep up, for me personally protein doesn't help to satiate me either. Part of it is that (for me) it's much easier to get into a habit to eat too much than to keep up the habit of eating just enough (I dare say 2+ years of keeping it low is a habit, but now for 3 wars annually 5kg was added: next try keto, hope it works as well as advertised)
You can think of your body as wanting to maintain homeostasis, which is one thing. That just means that if you binge once, you won't feel the need to continue binging at that level. It does not mean that anyone is genetically predetermined to be say 600 lbs.
To use that terminology though, your body could be said to have a "set point" that it aims for, but that "set point" can change. Nobody is destined to be fat, and if you lose weight, your "set point" will adjust.
> To use that terminology though, your body could be said to have a "set point" that it aims for, but that "set point" can change.
Which I acknowledged. You can decrease (or increase) your set point, but there is a limit to that. Thinking that everybody has the potential to be at BMI x simply does not match reality. The vast range of human physiology is stunning. Everybody is different. Some people need to carefully watch every bite they take and they still struggle with overweight, whereas others can eat "what they want" and they are underweight.
Totally neglecting any genetic component here is equally as false as neglecting the impact of factors like diet, exercise and environmental ones.
I see your point that there's no way that weight levels are entirely predetermined by genetics. To your point there are various cultures around the world who suffer more or less from obesity.
I don't understand this genetic determinism of weight to be the claim of Set Point Theory, which to my understanding is involved in energy homeostasis, which you acknowledged. Your body sets your metabolism, and it can tune it up or down. There are homeostatic processes in place such that your body "knows" whether it is underweight or overweight.
I'm not sure if there is a more specific objection you have to set point theory. It certainly has its limitations as to what it can explain, but it seems to be a useful concept or model.
You’re being downvoted, but as a genetically lean guy, I believe you’re right. I’ve never been particularly health conscious, but I’ve always been in “decent” shape - I eat the same things fat people eat, it just doesn’t stick to me for whatever cosmically unfair reason. Fat parents have fat kids - a fat five-year-old isn’t fat because he ate too much ice cream, it’s because he’s genetically predisposed to be.
There do exist some arguments for this, eg overweight parents with overweight kids, but obviously there isn’t some kind of ‘working class gene’ even though children are reasonably likely to have the same social class as their parents, and wealthier countries may have, on average, taller citizens even though height is strongly heritable. But one would certainly still expect genetic variation in eg thyroid function or whatever.
A few simple observations which don’t support the relevance of this genetic determinism argument:
- a few hundred years ago very few people were overweight. But maybe many people lived their lives incredibly hungry the whole time.
- wealthy countries where getting sufficient food is not the issue have variation in population-level statistics for obesity. Even if one claims that these countries are on-average different genetically in some ways (unlikely in the sense that genetic variation between large classes tends to be smaller than the variation within), one would expect America to mostly be a mix of old-world statistics whereas they come out exceptionally instead.
It seems to me that cultural expectations around food and weight will have a big difference and variation between countries, and that the kinds of food available and commonly consumed (eg sugary drinks, unhealthy fast food, etc) may be a big influence.
But none of this would mean that a particular individual is or is not overweight because of genetic factors rather than their environment.
Check out The Shangri-La Diet by Seth Roberts for a way to hack your set point with a daily tablespoon of flavorless cooking oil. I'm sure someone on the web has written up the details if you don't want to read the book.
