Yep, overeating (and, to some degree, not enough moving around) is the reason. True.
But “just personally do better” doesn’t work very well when applied as a medical intervention (they have tried, and checked, over and over, a hundred different ways), even with lots of follow-up and monitoring, and it also doesn’t appear to be how other countries manage to be skinnier than the US. Between those two things, it really doesn’t look like a viable way to solve the obesity crisis—it doesn’t work when we try it, and it doesn’t seem to be what’s working anywhere else.
But “just personally do better” doesn’t work very well when applied as a medical intervention (they have tried, and checked, over and over, a hundred different ways), even with lots of follow-up and monitoring, and it also doesn’t appear to be how other countries manage to be skinnier than the US. Between those two things, it really doesn’t look like a viable way to solve the obesity crisis—it doesn’t work when we try it, and it doesn’t seem to be what’s working anywhere else.