[dkersten]

Probably because they're hungry a lot. The more weight you put on, the more food you need to eat.

Also, I read that the more sugars you consume, the more you eat as it messes with your insulin and therefore your body does not signal that you are no longer hungry even though you've eaten enough. Can't remember where I read this, so if anyone has any citations or wants to correct me if I got it wrong, I'd appreciate that.