The US’s obesity problem is more complicated than that. It’s not just that our portions are big. Americans have to work pretty long hours too. That means much of our lives we probably aren’t getting much exercise, and when we get home a lot of us don’t have a lot of energy to cook so we probably eat a lot more pre-packaged food. Stress also contributes a lot to weight gain.

And once you have gained a lot of weight, all of those problems, plus the fact that healthcare is so expensive, make it even more difficult to lose.