When I was in grad school and working in a policy center, one of my friends went to the corner where an outdoor vendor sold some wonderful Indian chicken and rice. He cooked raw chicken out there in the open sun on the streets of New York, but our digestive systems were young enough to withstand it.

When my friend came back into the office to eat her chicken and rice at the desk, she told me that some stranger on line turned to her and said "you shouldn't be eating this." My friend was overweight, and frequently had random people come up to her on the street who felt that it was important to point out this fact to her. Like she didn't know.

There are two dark sides of the anti-obesity movement. The first dark side is shame. Now, shame in some cases can be a very effective method of reducing undesirable behavior. It has helped millions of people quit smoking or at least hide it from others. But there's something icky about it, too, especially when it's heaped at kids who don't have control over what is served for dinner and who have been cursed with slow metabolisms.

Marc Ambinder did an excellent job discussing his own battle with obesity and the humiliations that he faced as an over weight man in America. 

The other dark side of the anti-obesity movement is that many people are simply unable to control their weight. Diets and exercise don't work. Ambinder only conquered his weight through surgery, which reduced his stomach to the side of a walnut. How useful is it for Jamie Oliver to be yelling at schools about french fries, when for many people, the problem is deeper than french fries? Ezra Klein thinks that the forces that create obesity are so strong that "a mix of surgeries and pharmaceuticals eventually becomes our society's answer to obesity."

Klein also writes,

Obesity is much more structural than it is personal. That's why it's so
depressingly predictable. It afflicts certain communities, with certain
socioeconomic characteristics, and it has only really emerged across a
certain time period. Those communities contain a lot of different
individuals, but their environments and their time and money stresses
and their transportation and grocery options and their street safety
and exercise opportunities are broadly similar. How we live has changed
much more quickly than who we are, and no effort to turn back the tide
on obesity will succeed without an accurate understanding of what's
made us obese.

In other words, beating obesity means a complete overhaul of society from transportation to grocery options to healthcare. A jog on the treadmill isn't going to change anything.