I think robotics will solve this issue.

Today, automated cooking makes food that is unhealthy. Industrially processed food equals bad food. I think this is a large part of the reason for obesity. There is so little healthy food that is cheap and requires no manual effort to cook.

With sufficiently advanced robotics, the equation changes. All food that humans can cook well today becomes available with no cooking-cost. The availability of tasty and healthy food, at low cost, with no effort involved in preparing it, should be a game changer in more ways than one - and obesity ought to go down.

(Side-note: that the cost of cooking today is not in money, but in effort and time, doesn't make it less deterring but rather more so.)