I ride a train every week at the same time as a lot of kids going to college (UK, so ~18 years old), in any given carriage you always see 2-3 students who would have been the fattest in the year when I was at college ~ 10 years ago.  The overall rise in obesity as a statistic doesn't capture that it's not a rise in beer drinking amongst men in their forties, but largely in the young.  If you're morbidly obese by age 20 what sort of life are you going to live?  Even outside the extremes, a good 50% are noticeably overweight, with double chins and flabby arms :-(