Obesity

I was listening to people on the radio talking about the growth of obesity – one of the contributors was, I think, suggesting that most (or a lot of) overweight people were so because of genetics not because of overeating.  I know nothing about the subject but I am pretty certain that there was only one boy in my school of 600 or so who was called (albeit he should not have been called that) fatty – that was in the mid to late 50s.