Do Sports Drinks Promote Obesity?

With the mayor of New York City and a growing chorus from public health authorities all linking the consumption of soft drinks to obesity and related ills, the sale of sugar-sweetened sodas has been tapering off over the last several years. However, the sale of other sugar-sweetened drinks, including "sports drinks," continues to grow. A study presented at the annual scientific meeting of the Obesity Society this past September suggests that the public perception of sports drinks being a healthier option than sodas may be incorrect.Data on nearly 11,000 children (9-11 years old initially) of participants in the ongoing Nurses' Health Study II were tracked over time by Dr. Alison Field and her colleagues at Harvard's Medical School. After 2 years of follow-up, the kids gained almost 2 lbs on average for each can of soda they drank daily. However, this study also found that kids put on even more weight for each bottle of sports drink that they consumed daily. On average, each bottle of sports drink consumed daily resulted in a weight gain of 3.5 lbs over two years. That’s almost twice as much as the weight gained for each can of soda.  Over the life of this study, which began in 2004, consumption of sugar-sweetened sodas declined slightly among the participants, which mirrors the national trend, but the consumption of sports drinks, particularly among boys, increased significantly, which also matches the national trend. A typical sports drink is sold in a 20-ounce bottle and provides about 125 kcal of sugar. By contrast, sodas are most commonly sold in 12-ounce individual cans or bottles, and contain 120 kcal of sugar. Many schools, often pressured by parents, are now removing sodas from their vending machines and replacing them with presumably healthier sports drinks.So while most Americans are becoming increasingly aware that consuming sugar-sweetened sodas likely promotes weight gain, the shift toward sports drinks seems to be driven by a successful marketing strategy that is promoting salty sugar-water as part of a healthy lifestyle. As a result, many parents now buy sports drinks instead of sodas, thinking they are in fact a healthier option for their kids. However, while sports drinks may be somewhat lower in sugar than sodas (per ounce) they also typically come in larger containers. In addition to sugar, sports drinks also have far more salt/sodium than sodas, and increased dietary salt promotes increased thirst.Bottom Line: With both obesity and hypertension on the rise in children in the United States, it seems likely that the increasing consumption of sports drinks in kids is at least partially responsible. Both children and adults should be encouraged to consume water when thirsty rather than sports drinks.By James J. Kenney, PhD, FACN