Of all the absurd aspects of present panic over fat, the most absurd is the idea that it makes sense to spend scarce public health resources on trying to make people thinner. We have no idea how to make fat people thin. This overwhelmingly obvious empirical observation is routinely rejected by people who ought to know better.
Update: An interesting ideological aspect of this is the degree to which lefty folks who usually have no trouble understanding structural arguments turn into the offspring of Horatio Alger and Ayn Rand when it comes to fat. For instance, if you said to such people “We know how to end poverty. Just tell poor people to do X and Y, and as long as they do X and Y they won’t be poor,” and then it turned out that a social policy based on telling poor people to do X and Y resulted in failure 98% of the time, and in fact produced a net increase in the poverty rate, they would consider your opinion to be idiotic on its face.