If I ate myself silly I could never get my weight up to 560lbs. Maybe 250, maybe. It does take that kind of metabolism plus unlimited food supply to reach those huge weights. And never, in the evolutionary history of humans, has refusal of available food been any kind of evolutionary advantage. We have never had fat or sugar enough until modern times, and only in the past 50 has fat and sugar been cheap 'junk' food. So, when there is much cheap available sugary fat, those with a genetic predisposition to deposit fat readily ( those who would survive a famine- another common feature of most human experience for the past many millenia) will become huge. Unhealthy in this world, these are survivors from our bloody difficult past. I hate dealing with them, I've hurt myself trying, they smell and are so labor intensive. But the obesity is NOT a character flaw or a moral issue. Not to say fat folks are saints, but let's not get cause and effect confused. Trap yourself inside their bodies, and how good a person are you likely to be? If you were that much overweight, would you go on a diet, or would you just say- what the hell? And eat whatever you wanted because it really made no difference?