Mayor Bloomberg's proposed soft drink ban sets him up for a battle with corporate interests.Ernst Vikne/Flickr
My boyhood included occasional sugar-sweetened beverages (SSBs)--in 6½-ounce bottles. The current default is triple that size--a 20-ounce bottle--with many sizes larger yet. McDonald's has a 32-ounce serving and Burger King has 42 ounces. KFC has a 64-ounce Mega Jug, and the large soda at Regal Movie Theaters is 54 ounces. There are many more such beverages--entire new categories such as sports drinks, teas, vitamin waters, and energy drinks--sold at every turn and marketed heavily to both adults and children.
As everyone knows by now, Mayor Michael Bloomberg of New York, in concert with the NYC health department, is proposing to address this through a regulation that would limit the size of sugar-sweetened beverages sold in restaurants, movie theaters, and street carts to no more than 16 ounces. Is this good policy? The reaction has certainly been mixed, and even Brian Wansink, my colleague and friend, who did some of the portion-size studies the health department cited in announcing the ban, says he thinks it won't work . I do.
The big soda companies and restaurant industry have, of course, already begun to fight this with everything they have, as Marion Nestle has been tracking. They have reason to be concerned. Profit margins on these beverages are enormous--90 percent, as compared to, for example, 10 percent for produce. And profits increase as people buy bigger portions. The additional cost for the soda companies and restaurants to serve larger sizes may be mere cents for a larger cup and the extra liquid. Consumers are willing to pay much more than these few cents. The companies cash in. Consumers lose.
People are highly responsive to food triggers. Contrary to the belief that eating shuts off when enough nutrients have been consumed, human eating gets pushed around considerably by things like portion sizes. Most surprising is that consumers are largely unaware they are eating more.
Two phenomena drive this portion-size effect. One is that both adults and children eat more when they are served more--more foods and more liquids. Studies on increasing portions of liquids such as sugared beverages and soup and foods such as macaroni and cheese, sandwiches, pasta, and potato chips show increases in eating as large as 25-50 percent. Furthermore, consumers do not report feeling more full even though they have eaten more, and tend not make up for the excess by eating less at subsequent meals.
The second driver is something known as unit bias. People tend to consume food in units--typically whatever is in a bag, a bottle or a box. As bags, bottles, and boxes get larger, people consume more. Industry has systematically increased the sizes of these containers so they bear little relationship to what they were just a few decades ago.
This still leaves a key question. Why focus on sugar-sweetened beverages? Why not focus on portions of pizza, fast food, or snack foods? Public health officials around the country have made reduction of SSBs a top priority. The reasons are clear. These products are the single greatest source of added sugar in the American diet, they represent empty calories (they have no nutrition at all), they are marketed aggressively by industry, and, most notably, they act on the body differently than calories contained in solid foods. People do not feel as if they have had as many calories when they are delivered in beverages.
How will the companies react after the massive PR campaign they've already got under way? I expect lawsuits, and new industry-funded studies that will show, contrary to a large number of existing studies, that portion size does not have an effect on eating or weight.
Some argue against the NYC action by saying some people will rebel and buy more soda in protest, or will buy the same amount they always did, but in multiple servings that will penalize them with higher prices. Certainly, for some people this will happen. There are speed limits and some people speed, and there are high tobacco taxes and some people smoke anyway and pay more. But the death and disability that would ensue by removing such laws would be massive.
NYC has stood strong against industry lobbing, with pioneering efforts in the past such as banning trans fats from restaurant foods and requiring restaurants to provide calorie information to consumers. Other cities and states have followed. It is important therefore, that NYC get it right. The portion size initiative is another example of strong leadership.