How Bloomberg's Gigundo Soda Ban Will Backfire
In The Atlantic, Brian Wansink and David Just lay out how Bloomberg is not only a dietary fascist but a facile one:

On June 1 -- National Donut Day -- New York City's mayor proposed a restaurant ban for any soft drink over 16-ounces. The hope is that by banning big drinks people will drink less and weigh less. He and others cited our research as the science behind the policy. Indeed, a dozen of our studies show when you randomly give people large sizes of food like popcorn and French fries, they overeat. Another of our cited studies showed that people ate 73 percent more soup when eating from a soup bowl that secretly refilled itself.

There's a critical difference between the lab and Lexington Avenue that the mayor's office didn't account for: when Joe the Plumber and Bob the Banker buy soft drinks, they buy the size they want. They aren't randomly forced to take a 44-ouncer when they really wanted a 12-ouncer. Moreover, their Coke or Pepsi doesn't magically refill itself. If that happened, they'd overdrink. Instead, most restaurants give us a choice of a small or large drink -- just as nearly every fast food outlet gives us a choice of small, medium, or large fries, and every movie theatre gives us a choice of small, medium, or large popcorn. People who want a little buy a little, and people who want a lot figure a way to get it.

Yes, we have found that when people are given larger portions, they do drink or eat substantially more. But to claim that these results imply that the ban will be effective is to ignore our larger body of work. In our experiments, subjects were given larger or smaller portions of food in a dining or party setting, where they were unlikely to notice portion size. It is exactly because participants weren't paying attention that we got the results we did.

The mayor's approach, however, overtly denies people portions they are used to be able to get whenever they want them. In similar lab settings, this kind of approach has inspired various forms of rebellion among study participants. For example, openly serving someone lowfat or reduced-calorie meals tends to lead to increased fat or calorie consumption over the whole day. People reason that because they were forced to be good for one meal, they can splurge on snacks and desserts at later meals.

...150 years of research in food economics tells us that people get what they want. Someone who buys a 32-ounce soft drink wants a 32-ounce soft drink. He or she will go to a place that offers fountain refills, or buy two. If the people who want them don't have much money, they might cut back on fruits or vegetables or a bit of their family meal budget.

Who buys large soft drinks? It's not just the people who may have some disregard for their weight. It may also be the construction worker who buys a single drink and nurses it all day. It may be the family of three who decides to split a single drink to save money.