> Mere mention of a fact like obesity differences in population doesn't imply personal responsibility.

If there is no personal responsibility whatsoever in obesity, then this statement is true.

> US has a market, culture, and educational system that's as much to blame as individual choices.

If this statement is true, then there is still some personal responsibility in obesity.

Both statements can not be true at the same time. Also, culture and education doesn't absolve anyone from personal responsibility.