Scott Atlas from the Hoover Institution has an editorial in the Philadelphia Inquirer arguing that health insurance should be more like car insurance, where people who he claims make poor behavior choices have to pay higher premiums. He specifically singles out fat people, comparing obesity to smoking to argue that obese people have shown poor personal responsibility and therefore should be required to pay more into a system that they will tax more with higher rates of heart disease and diabetes. Leaving aside the questionable morality of treating people's bodies and lives like they're objects such as cars, the argument has a major hole in it: There's no reason to think that the reason people end up fat is because they made the decision, as fully formed adults, to overeat and not exercise.
You'd think all the attention paid to childhood obesity would have put the topic on the radar of anyone who wants to write about health care policy, but Atlas doesn't really seem interested in the subject. The brutal reality is that the reason a lot of adults are fat is that they were fat as children. Research shows that obese children are at least twice as likely to be fat adults as non-obese children. Children aren't generally recognized in our culture as fully capable decision-makers. It's widely acknowledged that the responsibility for keeping children from getting obese lies not with the children, but with the parents. Charging adult fat people higher premiums to punish them for what we all accept is the parent's fault is simply unfair. Sure, many fat adults became fat as adults, but the portion that started out fat as children is significant enough that charging higher premiums would unfairly ding them.
Yes, I know the rejoinder to this: Fat people should just lose weight! But the scientific evidence basically makes that solution impossible. Most fat adults have been highly motivated for most of their lives to lose weight, and yet they can't do it. The overwhelming scientific research shows that obese adults who diet will lose a bunch of weight and then gain it all back, and usuallly more. Tara Parker Pope at the New York Times ran down the explanations of why this is: Your body basically fights to stay the highest weight you've ever been. If you lose weight, your body floods with hormones that make you hungry. Your metabolism is also set at the point it was at your heaviest, meaning a person who weighs 150 pounds who used to be fat has to eat significantly fewer calories to stay at 150 pounds than someone who has always weighed 150 pounds. For a fat person to become a thin person, they have to embrace a lifestyle of constant starvation. Feeding a feeling of starvation is one of the strongest urges people have; faulting someone for eating when they feel they're starving is akin to faulting someone for wetting themselves if they've been denied a bathroom for 12 hours.
A sane, rational approach to the health crisis stemming from poor nutrition and exercise would be to change the circumstances that make people fat. Americans aren't the fattest people on Earth because we are uniquely absent of will power, nor is there a reason to think that obesity is rising because American self-control is somehow mysteriously declining. It's an environmental issue; we live in a culture where the cheapest food has the most empty calories and exercise opportunities elude huge portions of society. If we changed those factors, it would go a long way to reducing the strain of diabetes and heart disease on our health system.