Sugar-sweetened soft drinks, obesity, and type 2 diabetes.

SUGAR-SWEETENED SOFT DRINKS CONTRIBUTE 7.1% OF total energy intake and represent the largest single food source of calories in the US diet. Coincidentally or not, the rise of obesity and type 2 diabetes in the United States parallels the increase in sugarsweetened soft drink consumption. Several studies have found an association between sugar-sweetened beverages and incidence of obesity in children. In one study, the odds ratio of becoming obese increased 1.6 times for each additional sugar-sweetened drink consumed every day. Increased diet soda consumption was negatively associated with childhood obesity. The article by Schulze and colleagues in this issue of JAMA represents another link in the chain of evidence. This study provides additional evidence that excess calories from sugarsweetened soft drinks are responsible for the increasing prevalence of obesity among adults and also implicates sugar-sweetened soft drinks as a cause of type 2 diabetes. One of the significant features of the study by Schulze et al is that its results are based on longitudinal data. Studies based on cross-sectional data may be biased because many overweight or obese persons will switch to drinking diet soda as a way of combating their increasing weight. Thus, cross-sectional studies may underestimate the link between sugar-sweetened beverages and overweight, since obese persons may switch to diet soft drinks to lose weight. Longitudinal data allow researchers to follow up with participants and account for any switch to diet drinks. Second, the study reports that women who increased their sugarsweetened soft drink consumption also increased their reported total calorie consumption, by 358 kcal/d on average, with most of the excess calories accounted for by the soft drinks. This finding holds for fruit punches and fruit juices as well as sugar-sweetened soft drinks. This result supports the finding that when individuals increase liquid carbohydrate consumption, they do not reduce their solid food consumption in response. An increase in liquid carbohydrates leads, perversely, to even greater caloric consumption. One 12-oz can of sugar-sweetened soda contains 150 kcal and 40 to 50 g of sugar. If these calories are added to a typical US diet with