Originally posted by Eladar
Because always being hungry is miserable.
research has shown that excessive hunger is not the reason why most fat people are fat although there are definitely some relatively rare exceptions. This is why most studies that involved giving appetite suppressants to overweight people have generally shown such disappointing results with the appetite suppressants not working or at least having little effect for most of the overweight people given them.
However, research has shown there is a small minority fat people that are fat because of hormone abnormalities that make them excessively hungry. But, for the vast majority of fat people, they are fat because they lack the ability to resist eating lots and lots of delicious food, not because they are on average more hungry than skinny people but because they don't have the same self-control specifically when it comes to eating which means they eat even when their bodies are telling them they are NOT hungry! And thus they overeat.
There is a possible evolutionary reason for this which I think is probably true because it makes sense; in the caveman days, it would be best to binge and put on weight, even become fat, whenever there is a bonanza of food, so that you got more fat reserves to survive possible food shortages and even famine later. But, in the modern day, this survival tactic not only is generally no longer needed but it usually is counterproductive to survival -but evolution hasn't had sufficient time to catch up hence many people still binge.
I am skinny and yet I am not miserably hungry all the time -why do you think is that if simply satisfying my hunger would make me fat? Like most skinny people, when I am hungry, I eat. When I am not hungry, I don't. The only difference there between me and most fat people is that, generally, at soon as I have had my fill, I stop just right there, and then don't eat until I definitely am hungry again.