A study out this month in the New England Journal of Medicine (NEJM) has found that replacing sugary drinks such as soda with water or sugar-free alternatives has a significant impact on calorie consumption and weight gain among adolescents. Researchers in Boston followed 225 high schoolers for two years. During the first year, half the participants, the intervention group, received free home deliveries of bottled water and diet soda, while the other half, the control group, received a $50 gift card to a local grocery store. The parents of the group receiving calorie-free beverage deliveries also participated in monthly motivational calls encouraging reduced consumption of sugary beverages. At the end of the first year, all interventions ended in order to determine long term effects of the intervention. Both groups reported their dietary intake and had their BMIs measured at three points: the beginning of the study, after year one, and after year two at the end of the study.
After the year one intervention phase, the intervention group gained an average of 3.5 pounds, while the controls gained an average of 7.7 pounds. Participants receiving calorie-free beverage deliveries had reduced their sugary beverage consumption to nearly 0, while the other group’s sugary beverage consumption remained the same as baseline. The intervention group’s sugary beverage consumption also remained lower than the control group a year after the intervention ended. The intervention group’s overall calorie intake was also reduced.
A second study also in NEJM found that the impact of replacing sugary drinks with soda was also significant among younger children. Researchers in Amsterdam followed 641 children between 4 and 11 over 18 months. Half of the children were given a sugary beverage to consume during their mid-morning break, while the other half received a sugar-free beverage. While over a quarter of the participants dropped out, the researchers were still able to find a significant difference in the amount of weight gained by those consuming the sugary beverage (16.2 lb) instead of the sugar free beverage (13.9 lb).
These findings come just a week after New York City became the first U.S. city to limit access to sodas, with a ban on all sodas over 16 oz. Though the results of the ban are yet to be determined, these findings suggest that limiting children’s consumption of sugary beverages may be an important tool for reducing childhood obesity.