This very thread is evidence of ignorance regarding weight gain, biology (leptin, insulin, insulin resistance, hormones, etc.) and body types.
Someone has been watching too many Hollywood movies.
How can 63.1% of Americans, or 63.1% of any group, be "overweight"? Doesn't the average just need to be re-calculated -- or questioned as being unrealistic?
Not every overweight person is a glutton, eating bags of potato chips and tubs of ice cream. Some overweight persons might eat no more than you -- but their metabolisms aren't as kind to them as yours is to you.
Judge not, lest ye be judged.
Just for starters, there are different body shapes/types. Not every non-sixpack belly is a "muffin top" or pure cellulite. Some body types have a lot of muscle, so even when some fat is present they "wear it well".
Male opera singers often have a large belly, but it's not a jiggly bowl of jello.
And even that layer of fat that they wear well/poorly, might have got there any number of ways. They might have eaten too many carbs like bread. They might have been full/hungry exactly as much as you, and still gained weight. It happens to more people than you care to think about.
But I know, it makes one feel superior to consider everyone overweight to be a Pop Tart-gorging glutton.
Speaking of Pop Tarts, I know of some children (no, not mine thank God!) who stole a CASE of Pop Tarts -- 40 pop tarts among 7 children. On Good Friday no less! They are all skinny as a rail. So they, who DO seem to have a problem with gluttony, won't get judged, while some poor man/woman with a slow metabolism will get judged 12 times a day.
Life certainly isn't fair!