[hnbad]

Does the study correct for the reason why the participants slept less than 6.5h/day? I'd suspect for many people the reason they don't get enough sleep is also the reason they find it difficult to maintain an optimal diet or exercise (and thus gain weight), i.e. stress.

[loeg]

For me it’s at least partially a choice. I’m not too stressed but find it easy to stay up late if I don’t make an effort to go to bed. (I had already observed that when I sleep more, it’s easier to lose weight.)