Can it not? Stop eating so much fructose and eat more fiber so you don't absorb as much of what you do eat. Can that guarantee the same results for every single person? I would guess not. It is a good indicator of the first thing to try to be healthier and lose weight? Seems like pretty overwhelming evidence to me and in fact mirrors my own experience with intentionally losing and gaining weight.

Most of the time this type of dismissal is more due to someone not wanting to face the idea of giving up sugar, which I can understand.