>Something changed over the last decade or more, and now no one wants to do any better than they currently are. They are despairing in content with themselves<

People still aspire to be attractive they just don't feel the same social pressure to chase it that they used to. Personally I don't see the problem for the USA, if people are happy being unhealthy then let them be unhealthy. If this was Europe I could see a public cost argument but US businesses are already starting to charge more to people who are inconveniently obese so I don't see why it's a real concern.