Another issue is that we as a society are now a lot wealthier, in the past only the rich could afford it get fat, for example, everyday middle class workers only ever got a hit of sugar as a special treat on special occasions, some never got to taste it.
Today as our general average wealth in western countries is higher then ever, everyone can afford to get fat. It will only get worse as we prosper unless awareness is increased.
It's already starting, local councils issue magnet food balance charts to stick on fridges, it's a small step, but in the right direction.