In some cases, they have a BMR that aids them.
BMR won't affect this. My weight, excluding temporary deviations due to illness, has been between 120 and 130 pounds for the last forty years. I only have a detailed record for the last 11 years (4011 days, to be precise), during which I have weighed myself nearly every day. Linear regression on the data gives a gradient of about -0.1 grams per day, or -400 grams over the whole period. However, as the standard deviation of the weight is about 700 grams, this is indistinguishable from zero (as I knew already from eyeballing the graph). In terms of calories, using the usual (but, it seems, not very accurate) estimate of 3500 calories per pound of fat, this is less than 1 calorie per day.
0.1 grams and 1 calorie per day are at least two orders of magnitude smaller that the precision with which you could measure daily diet or exertion.
According to an online BMR estimator based on age, weight, and height, my BMR has declined by 70 calories per day over that time, i.e. 700 times the daily trend in body weight. Add to that the fact that in the first half of the period I was driving somewhat more and cycling somewhat less than in the second half, yet no corresponding change in weight is visible in the graph. (Average weights for the first and second half differ by 0.22 pounds. My scales only have a resolution of 0.2 pounds.)
So it is clear that the factors varying from day to day and year to year completely overwhelm the size of the long-term trend. Yet despite that, the long term trend is effectively zero.
The only type of mechanism that can produce phenomena like this is active regulation. But the regulation is not being performed by "me", i.e. by deliberately chosen actions in response to observing my weight. (It was just as steady before I began daily measurements.) By what, then? I don't think anyone knows the answer to that.
Now, what would happen if I were to eat less? My experience is pretty much the same as what Eliezer has described: I get light-headed with hunger, and great mental and physical efforts become beyond me. I am fortunate enough to have no reason to do so. But I recognise that it is nothing but good fortune, and I am not going to smugly tell anyone else that they just have to pay the price, when the price may be beyond their means, and the price to me is zero. Eliezer's job and vocation is thinking, and if he cannot do that while dropping 100 pounds, then he cannot drop 100 pounds.
...Now, what would happen if I were to eat less? My experience is pretty much the same as what Eliezer has described: I get light-headed with hunger, and great mental and physical efforts become beyond me. I am fortunate enough to have no reason to do so. But I recognise that it is nothing but good fortune, and I am not going to smugly tell anyone else that they just have to pay the price, when the price may be beyond their means, and the price to me is zero. Eliezer's job and vocation is thinking, and if he cannot do that while dropping 100 pounds, then he
The most recent post in December's Stupid Questions article is from the 11th.
I suppose as the article's been pushed further down the list of new articles, it's had less exposure, so here's another one for the rest of December.
Plus I have a few questions, so I'll get it kicked off.
It was said in the last one, and it's good advice, I think:
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.