You are what you eat. I realize there are cases where various ailments cause one to be obese, but in my experience you literally are what you eat. Some of my best friends are overweight & it's not because they have an ailment. It's because they want another hot dog or cheeseburger an hour after their biggie fast food meal.
According to my company representative the main reason our insurance rates go up every year are due to complications from obesity. Not smoking. They expect 75% of Americans to be overweight by year's end.
The truth of the matter is that it's hard to find food that isn't crap. I was once overweight & when I decided to change my lifestyle I didn't know what the hell I was going to eat. For many Americans if you cut out fast/fried food you're lost.
Pound for pound, the amoeba is the most vicious animal on earth.