Comment by paulpauper

I ain't buying it. There is a replication crisis in the sciences, and it would not surprise me if this is wrong too, or at least that the results do not mean what they are purported to mean. I have read many personal accounts here and elsewhere of men who were able to eat a lot in their late teens, 20s, and early 30s, and then suddenly by their 30s gain a lot of weight despite not changing their lifestyle or diet much.

Inactivity alone does not explain it. Consider for example Bill Gate...according to his resume, in which he lists his precise height and weight, in his 20s he weighed just 125 pounds. It's evident he has put on a lot of weight, all in his mid-section, well before he turned 60. His job literally entailed sitting at a computer all day coding. If anything, given his philanthropy efforts and retirement, he is more active now than he was in his 20s when working full-time at Microsoft. Is he eating more? I doubt it.

For so many people, celebrities for example, a switch is flipped in which there is sudden weight gain after the age of 30 or so, like John Travolta, Stevie Wonder and others. Because celebrities are photographed, you can see the weight progression and the abrupt jump in weight. Even with money for personal chefs and trainers, not gaining weight is hard.

I can personally attest that if I ate the same quantity of food now as I did at 20 I would gain weight, and no I'm not 60. And I am just as active , maybe more so. So yeah not buying this study.