This issue is well framed
by the Economist, as usual:
For those (like this newspaper) who believe that the state should generally keep its nose out of people’s private affairs, obesity presents a quandary. “A millionaire may enjoy breakfasting off orange juice and Ryvita biscuits,” Orwell pointed out; “an unemployed man doesn’t…You want to eat something a little bit tasty.” If people get great pleasure from eating more than is good for them, should they not be allowed to indulge themselves? After all, individuals bear the bulk of the costs of obesity, quite literally. They suffer at work, too: their wages are often lower and, in America, some employers also make fat workers pay more for health insurance.
Yet in most countries the state covers some or most of the costs of health care, so fat people raise costs for everyone. In America, for instance, a recent paper estimated that obesity was responsible for a fifth of the total health-care bill, of which nearly half is paid by the federal government. And there are broader social costs. The Pentagon says that obesity is shrinking its pool of soldiers. Obesity lowers labour productivity. And state intervention is justified where it saves people from great harm at little cost to themselves. Only zealots see seat-belt laws as an affront to personal liberty. Anti-smoking policies, controversial at first, are generally viewed as a success.
And this is a good point about obesity being more than just a matter of personal responsibility:
Obesity is, at its heart, the result of many personal decisions. But the rise of obesity—across many countries and disproportionately among the poor—suggests that becoming fat cannot just be blamed on individual frailty. Millions of people, of all cultures, did not become lazy gluttons at the same time, en masse. Broader forces are at work. The government can try to influence them by discouraging overeating. But how?
And more here, on how, unlike climate change or cigarettes, there is no single big solution to obesity; rather that the state will need to pursue a number of smaller solutions in schools and communities:
Drugs and surgery can help in the most extreme cases. They do not, however, offer a solution to the wider problem. Economists, faced with behaviour they don’t like, tend to favour imposing “sin” taxes. But eating fatty and sugary foods is not a “sin”, even in the fiscal sense, for unlike cigarettes, fatty foods are not uniformly unhealthy. Moreover, since poor people spend a higher proportion of their income on food than rich people do, such a tax would be regressive. It would also be an administrative nightmare, as the fat content of each item of food would have to be measured. Denmark, which imposed a fat tax in 2011, abandoned it after a year.
In the absence of a single big solution to obesity, the state must try many small measures. Governments, some of which already intervene a lot in the first few months of people’s lives, should ensure that parents are warned of the dangers of overfeeding their babies. Schools should serve nutritious lunches, teach children how to eat healthily and give them time to run around. Urban planners should make streets and pavements friendlier to cyclists and pedestrians. Taxing sugary fizzy drinks—which unlike fatty foods have no nutritional value—and limiting the size of the containers in which they can be sold may work. Philadelphia and New York, for example, have implemented a range of such policies, and have seen child-obesity rates dip ever so slightly.
I would say that the article is worth reading throughout, but I suppose I've linked to most of it already.
For what it's worth, I don't think that big solutions to obesity are inherently flawed. The problem is that humans don't yet understand the areas of weight gain and weight loss well enough to design a policy that strikes at the heart of the obesity epidemic. We understand on a broad level that there are a number of factors that are correlated with weight gain (lack of exercise, fatty foods, overeating, etc...), and so we try to design policies to reduce these behaviors. But we don't fully understand, say, the biological process for how people lose weight.
I suspect that once we do understand this, there will be medications or surgeries that will do a better job of fighting obesity than any government policy. In the meantime, government will probably be reduced to tinkering around the edges, as it has been doing in recent years.
