Becker rejects the idea largely because of imperfect knowledge and government susceptibility to special interests:
It is not clear that government bureaucrats generally understand why consumers make defective decisions, and even less likely that governments policies will help improve these decisions. As is well known, government officials, including regulators, legislators, and executives, are subject to powerful pressures from interest groups that often greatly affect public policies to the detriment of consumers.
I am not particularly interested in saving the obese from themselves. I am concerned about the negative externalities of obesity—the costs that the obese impose on others. Some of the others are the purchasers of health insurance and the taxpayers who pay for Medicaid and Medicare and social security disability benefits. Though the obese die on average earlier than the non-obese, which reduces their average health costs somewhat, the reduction is more than offset by the higher health costs that they incur (and by incurring impose, to a considerable extent, on others) because of the effect of obesity on chronic health conditions such as diabetes, heart disease, and joint problems, on mobility generally, and, because of these conditions, on ability to work (and hence on social security disability costs) and on employability (and hence on unemployment insurance costs). Obesity kills, but slowly, and en route to dying the obese run up heavy bills that, to a great extent, others pay.
Even more serious are the harmful effects of obesity, and of the food habits that contribute to it, on children. Obesity is sometimes a consequence of genetic factors but more often of gluttony, eating the wrong foods, eating between meals, drinking large quantities of sugared soft drinks (the straightest path to obesity), failing to exercise or even to move around, lack of self-discipline. These qualities “nourish” obesity and are in turn nourished by it, in a vicious cycle. Children who grow up in a household of obese parents (often there is just one parent, and she is obese) very often acquire the same bad habits.