Hasten to add that I don't mean obese and unfit, as clearly that isn't a good idea.
Our natural evolutionary propensity is to eat lots when it's available in order to have enough stored fat for the lean times. Clearly that is a problem in a world where food is freely available and more of an entertainment than mere nutrition. And where we don't need to move much to get from one place to another or get warm.
So, that being the case isn't it likely that this is a problem that isn't going to go away when it means fighting your own instincts.
Should we just concentrate on the exercise side of the equation - ie do move more and find something you like to do, rather than don't eat this and that. And change our aesthetic sense to accept the endomorph as just as beautiful as the ectomorph.