I'll bet family structure is related as well. You didn't use to need a two income household for one thing, so the wife would usually stay home and take care of the family. It's more common to need both parents to work now, and it creates a slippery slope in that respect. Now you create a generation that didn't learn the important skills their parents had, such as cooking from scratch. The women are undesirable mates as they cannot provide for their families, people start getting married and pairing up later. It has become socially unacceptable to get married at a young age. Our environment and culture created a world that is like cake to fatties, irresistible. Food is right there for the taking with zero effort so why put it in when you can just eat the cake? Stupid people go for the cake. Smart people change their circumstances and habits to moderate their cake intake with the less readily available but all around better options. Add the echo chamber that is the Internet to the mix and you shouldn't be surprised what happens.