In an opinion piece in the Journal of the American Medical Association, Thomas Farley praises New York City policies and calls for ramped up regulation to fight obesity:
New York City supported a 1-cent-per-ounce excise tax on sugary drinks to lessen the industry's financial incentive to market large portion sizes and to encourage consumers to choose smaller portions and switch to low-calorie beverages. The city also supported a change in policy on the Supplemental Nutrition Assistance Program that would have prohibited the use of program benefits to purchase sugary drinks, arguing that government should not subsidize the purchase of a product known to be particularly unhealthful. In addition, the city's health department proposed a cap on the portion size of sugary drinks served at restaurants.
He doesn't justify the regulations by showing that they worked or by demonstrating that the benefits are greater than the costs. Rather, his key argument is that the government already regulates many areas of your life:
. . . tens of thousands of restaurant inspections are conducted each year, enforcing rules such as those mandating the temperature at which food can be stored, all to prevent foodborne infectious diseases. The federal government mandates safety features, such as seat belts, in automobiles. Governments at all levels prohibit the use of lead in paint.
The reason you should acquiesce to new government rules is apparently that you've already acquiesced to other government rules.
In the end, the argument amounts to little more than paternalism. People aren't presumed to know what is best for them so let the "experts" decide. It is telling that in the piece, Farley writes:
The sale of huge portions is driven by the food industry, not by consumer demand.
I don't recall the food industry ever forcing me to supersize my Big Mac.