I am 6'1" and 135 pounds, and no, I am neither Bulimic nor Anorexic. I simply eat many tiny meals throughout the day, which I have found helps people to develop a higher metabolism, in turn helping them to burn more calories throughout all activities.
Regular exercise is another way many Americans could stay not only "in shape" but also keep away from obesity.
Many people strive for a perfect appearance when they go on a diet or exercise program. They are too impatient with their results, because it takes a long time for someone's body to change from one type to another.
The emotional distress of not becoming what they sought out to be plunges many people into an emotional and physical depression, lack of physical activity, happiness, and healthy eating habits lead them back into obesity. I would know first hand.

The obesity problem is not just a food problem, but a social, mental, spiritual, and cultural issue.