Then they didn't stick to it, simple as that. Eat less than you burn = lose weight. Unless they broke physics, in which case we should put them in a sterile room and study them
> we should put them in a sterile room and study them
We have.
https://news.ycombinator.com/item?id=49319339
> Body adapts significantly over time when subjected to weight loss.
> There are compensatory physiological adaptations that favor weight regain, such as changes in energy expenditure and appetite.
> Even with sustained effort, maintaining the initial weight loss may become progressively more difficult because of those changes.
> This shows up in research as results like mean weight loss of ~9% at year 1 and ~5% at year 8.
> we should put them in a sterile room and study them
We have.
https://news.ycombinator.com/item?id=49319339
> Body adapts significantly over time when subjected to weight loss.
> There are compensatory physiological adaptations that favor weight regain, such as changes in energy expenditure and appetite.
> Even with sustained effort, maintaining the initial weight loss may become progressively more difficult because of those changes.
> This shows up in research as results like mean weight loss of ~9% at year 1 and ~5% at year 8.