On September 13, 2012, the New York City Board of Health enacted Mayor Michael Bloomberg’s proposal to limit the size of cups selling soda in New York City. The soda cup size ban over 16 oz only for facilities subject to inspection: restaurants, movie theatres, and stadium concession stands. Not covered are convenience stands, including 7-Elelven’s (and its king-size Big Gulp drinks), vending machines and some newsstands. Also not affected are fruit juices, dairy-based drinks like milkshakes or alcoholic beverages and non-caloric beverages. Fast food restaurants with self-service drink fountains would not be allowed to stock cups larger than 16 ounces. http://www.nytimes.com/2012/09/14/nyregion/health-board-approves-bloombergs-soda-ban.html.
There is no ban on buying two under 16oz cups of soda, selling ‘two for the price of one’, or free re-fills.
While most anti-obesity advocates shudder at the thought of sugar sweetened beverages, there is doubt over whether a ban on the size of the cup in which they are delivered is going to have much impact. Here’s why.
At 273 kcal a day, a person would put on about 28 pounds a year. This is not happening, so the caloric intake is probably balanced to a large, if not full extent, by energy expenditure. The CARDIA study of 18-30 African-American and white men and women found that physical fitness changes were most strongly associated with weight changes over 7 years. Weight changes in this study range from 5.2kg in white women to 8.5 in African-American women.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1380845/pdf/amjph00503-0109.pdf
To look at the combination of genetic pre-disposition to obesity and in the intake of SSBs, Qibin Qi and colleagues at Harvard School of Public Health looked at 32 genetic loci (called “risk alleles”) known to be associated with BMI. They grouped the 32 loci into 3 groups and looked at prospective 4 year beverage intake data from two large studies. Participants who were obese at baseline were excluded. They found a rising BMI from greater intake of SSBs. For every 10 risk alleles, the increases for BMI was 1.0 for one serving a month, 1.2 for one to four servings per week, and 1.85 for one or more servings per day. In a sub-analysis, they excluded the FTO gene, known for its impact on body weight, and found similar results. They concluded that “persons with a greater genetic predisposition to obesity appeared to be more susceptible to the deleterious effects of sugar –sweetened beverages on BMI. PubMed: Sugar-Sweetened beverages and Genetic Risk of Obesity The implication of this article is that NYC may have overreached…applying a rule to all when only some are most affected.
Two intervention studies were published in the New England Journal of Medicine, along with the study above. One, by Cara Ebbeling and colleagues, divided 224 overweight and obese adolescents into 2 groups. The first group received home delivery of non-caloric beverages and were followed for another year. The second group acted as controls. Consumption of SSBs in the first group declined significantly but at the end of 2 years there was not difference in BMI between the two groups.PubMed: Randomized Trial of SSB and Adolescent Weight
The other intervention study, by de Ruyter and colleagues, had a larger sample size (641 normal weight children from 4 yrs 10 months to 11 yrs 11 months) and was a double blind model. Half received a sugar-free non-carbonated beverage and the other have a sugared non-carbonated drink. 26% dropped out of the study. If this were an obesity drug study, a great deal would be made of this. Evidently they dropped out because they no longer liked the taste of the beverage. The researchers assume they went back to consuming sugared beverages. They found that “masked” replacement of the SSB by a sugar-free beverage significantly reduced weight gain and fat accumulation in normal weight children. The difference was 1.01kg. However, the authors calculate that approximately 0.8kg of the differences in weight gain was due to fat mas and associated muscle and other tissues. PubMed: Trial of sugar-free or sugar-sweetened beverages
You can listen to David Allison discuss the SSB issue and these studies at http://themixuab.blogspot.com/2012/09/do-sugar-sweetened-drinks-drive-obesity.html.
These studies were published in the New England Journal of Medicine September 21, 2012 edition. Mayor Bloomberg could have looked at other recently published studies to see the difficulty of regulating consumption of SSBs.
Levy et al looked at school nutrition policies and price interventions directed at youth consumption of sugar sweetened beverages (SSBs). They found that school nutrition and price policies reduce SSB consumption and that reduced SSB consumption is associated with a reduction in energy intake that “can” influence Body Mass Index Their review of the literature found that the effects of nutrition policies on BMI were less conclusive, possibly due to the lack of adequate follow-up period or that reduced SSB consumption in school is compensated for by increased SSB consumption outside of schools. The authors’ concluded that, “The reduction in energy intake from even just one 8-oz serving of SSB appears enough to have important effects on the prevalence of overweight and obese youth if policies are started at early ages and maintained.” PubMed: Review of the literature on policies youth consumption of SSB
Of course, the key word here is “if.” Some of the calculations of the benefits of reducing or eliminating SSBs, are premised on the assumption that the calories contained in SSB will not be compensated for by other caloric intake. PubMed: Effect of school district policy change on consumption of sugar An analysis of SSB consumption in middle schools compared students in states which reduced access and purchase with those that did not. The main finding was that SSB consumption was not associated with state policy, i.e. in-school access is reduced but overall consumption is not changed. PubMed: Banning all sugar-sweetened beverages in middle schools A study by Wang et al, calculated what a penny-per-ounce tax on SSBs would mean for health care costs and diabetes. They calculated that 40% of the calories in SSB would be replaced by other caloric intake and 60% of SSB calories would not be replaced. This would translate to a mean reduction of 0.9 pound in mean at the population level, with a greater impact on younger adults, a 1.5% reduction in the number of adults with obesity. This decline would further translate into a reduction of new cases of diabetes by 2.6% and cost savings over ten years of $17.1 billion. PubMed: Penny-per-ounce tax on sugar-sweetened beverages. However, the 40%-60% split was only an estimate, it wasn’t based on experimental or real world results.
News reports indicate 24 states and 5 localities which proposed taxes on sugar sweetened beverages failed in their attempts over the past 2 years. Industry resistance to taxes and regulation has been strong and effective. ( Reuters: Special Report: How Washington went soft on childhood obesity http://www.reuters.com/article/2012/04/27/us-usa-foodlobby-idUSBRE83Q0ED20120427, accessed April 28, 2012)
Worldwide, some 20 countries have banned all sugar-sweetened beverages from schools and about 12 have banned 100% fruit juice as well, according to Barry Popkin and colleagues. PubMed: Global Nutrition Transiiton and the Pandemic of Obesity Hawkes and colleagues have found that 26 countries have made explicit statements on food marketing to children and 20 or so are developing explicit policies in the form of statutory guidelines or approved forms of self-regulation. PubMed: Regulationg the commercial promotion of food to children
Denmark last year became the first nation to tax sugar but has since rescinded its tax because it was hurting domestic businesses while Romania has introduced a lower value-added-tax on staple foods. New Zealand is researching taxing foods with little or no nutritional value at higher rates than more nutritious foods. Professor Sir Nicholas Wald, director of the Wolfson Institute of Preventive Medicine has proposed an all-embracing SASS (salt, sugar, alcohol and saturated fat) tax. PubMed: Is a tax on junk food moving closer?
One alternative approach is to tax all SSB sales, whether in school or out of school. Researchers have pointed out that, in 2007, 34 states taxed soda sold in grocery stores and 39 taxed soda sold in vending machines at mean rates of 3.4% and 4.0% respectively. The tax was never greater than 10% of the price. Several studies are cited which showed no effect on BMI from such taxes. PubMed: A review of the literature directed at the youth consumption of SSB Sturm et al point out the greater benefit of larger tax than a smaller tax to affect behavior. PubMed: Soda taxes, soft drink consumption, and children’s body mass index.
For an excellent discussion of food taxes, see these presentations from University College, Dublin.
The New York City experiment will be tested in court and then it will be tested in practice to see if it actually has an effect on reducing weight gain or causing weight loss. But there are other public policy options worth exploring. Mayor Bloomberg also proposed a waiver for the city from the Department of Agriculture to allow restrictions on the purchase of certain foods by families with SNAP benefits. SNAP is the Supplemental Nutrition Program for Women, Infants and Children. SNAP is a federal program designed to reduce hunger and food insecurity among low-income Americans. In a study using store scanner data, Tatiana Andreyeva and colleagues at the Rudd Center for Food Policy and Obesity looked at patterns in the New England states. They found on average that SNAP households purchased 689 oz of beverages per month, including 399 oz or 58% of SSBs. The researchers estimated that SNAP spends annually between $1.713 billion to $2.05 billion on SSBs. They note that no-calorie beverages and water were equally available and no more expensive. SNAP households appear to obtain more total energy from SSBs than the general, higher-income population. PubMed: Grocery Store Beverage Choices by Participants in Federal food
So there are other public policy options. But this debate over SSBs show the problem with over-simplifying obesity to one source, fashioning a simplistic response, only to see the “solutions” fail. This stuff is difficult and we need to appreciate how difficult it truly is.
