As far as being overweight goes, that is in its infancy as a socially undesirable behavior and is more a biological problem for many people than a strictly behavioral problem. Not everyone is naturally skinny.
There is a theory that over-eating is a naturally evolved predisposition in some populations. This is because genes for over-eating were life savers for populations at risk from unpredictable and frequent famines. Body fat was a store of nutrients. Even now fat people are more prized as spouses, labourers, and parents than thin ones in such societies.Among some populations the genes persist.It's therefore more difficult to eradicate over-eating than smoking or even alcoholism.