I have to ask, why? (I'm not in the US, I should add). Like, sure, is the average American overweight? Yes. Are 80% of the top 20% of earners? Seems pretty doubtful, plenty of the rich look to be in reasonable shape.
That statistic suggests that 80% of successful people have such poor impulse control that they end up seriously overweight or obese. And I say that as someone who likes a treat every couple of days, but exercises enough to maintain a fairly healthy weight.
Admittedly if there were a GLP1 for procrastination, I'd be on that stuff like a shot...