Mayor Michael Bloomberg of New York City recently proposed a novel experiment to combat the rising obesity crisis in the United States – banning the sale of sugar-sweetened beverages (SSBs) larger than 16 ounces. According to New York Public Health Commissioner Thomas Farley, the new ban is based on evidence that sugary drinks are the single largest dietary source of sugar in this country and that over-consumption of sugar leads to weight gain, diabetes and a multitude of other medical conditions. This week, NEJM presents three research studies that provide additional scientific evidence for the role of SSBs in promoting weight gain and obesity.
The first of these studies, entitled “Sugar-Sweetened Beverages and Genetic risk of Obesity” found an association between consumption of SSBs and genetic predisposition to adiposity. In short, those who drank more SSBs also tended to have more genes associated with weight gain and obesity. More research must be conducted to help us better understand whether particular genetic patterns make certain individuals more susceptible to the deleterious effects of SSBs. One could even imagine the possibility of one day providing targeted obesity interventions to individuals found to have an elevated genetic risk.
The two other studies were interventions aimed at reducing the consumption of SSBs in children. A Dutch group randomly assigned 641 children to receive one eight-ounce can daily of a noncaloric, artificially sweetened, noncarbonated beverage or a sugar-containing noncarbonated beverage. At the end of 18 months, the investigators found that children assigned to the sugar-containing drinks gained more weight and had significantly higher BMI than those assigned to the artificially-sweetened beverages. A limitation of this study is that these Dutch children were predominantly white and fewer than 20% of the children in the study were obese or overweight. In the United States greater than one-third of children and adolescents are currently obese or overweight.
The third study, led by investigators from the Harvard School of Public Health, looked at the effects of a multicomponent intervention to reduce consumption of SSBs in 9th and 10th grade students. The intervention involved home delivery of sugar-free beverages every week, monthly motivational phone calls, mailings of reminders not to drink SSBs, as well as personal visits with the families every 4 months. After the one year intervention there was significantly less weight gain in the intervention group when compared with the control group. However, this difference did not persist at follow up one year after discontinuation of the intervention.
What can we learn from these studies? Obviously, childhood obesity is a complex issue and sugar-sweetened beverages are only one piece of the larger picture. However, we now have more evidence to support the claim that decreased consumption of SSBs may actually reduce weight gain in children. Targeting these beverages may be an important component of a comprehensive public health strategy aimed at tackling the growing obesity epidemic both in our nation and worldwide.
According to NEJM deputy editor and pediatrician Julie Ingelfinger, “Weight control is difficult, and studies like these, which might be used to set policy, are especially important.” But government laws and regulations can only take us so far. Parents must do their part to set examples for their children when it comes to eating habits and physical activity. Ingelfinger also reminds us that physicians can also play an important role in obesity prevention. “Many children are followed by their pediatricians from birth, providing each practitioner with the potential to make a difference in life-long habits.”
Do you believe regulation of SSBs is the right path to trimming the childhood obesity epidemic? Our latest Clinical Decisions builds on data from the three Original Articles described above. A brief patient vignette is followed by recommendations for and against regulating sugar-sweetened beverages for 12-year-old Meredith. Choose an option, and comment on your choice on NEJM.org. Voting is open until October 24th.