If you don't know what that is, a bunch of four-year-olds are given a marshmallow, and the experimenter leaves the kid alone in a room. The kid's told they can eat the marshmallow now, or they can wait until the experimenter comes back, and then they can have another. Essentially, it's an experiment in self-control. Who doesn't have self-control. Yep, fats.
All the kids were studied as they grew up, and the ones with self-control, who didn't eat their marshmallow right away:
Had lower BMI
Scored higher on the SAT*
Had higher salaries*
Were less likely to abuse drugs*
Had better relationships with their teachers and peers*
Better job performance*
Were more successful in college*
Were less aggressive*
Forgive me for that incredibly long list, but it shows people who lack a little thing called self-control, ie fats, are unsuccessful in just about every aspect in life.