"In all three cohorts, the combined genetic effects on BMI and obesity risk among persons consuming one or more sugar-sweetened beverages per day were approximately twice as large as those among persons consuming less than one serving per month," the authors said. "Viewed differently, persons with a great genetic predisposition to obesity appeared to be more susceptible to the deleterious effects of sugar-sweetened beverages on BMI."

Based on the results, the study authors argue the need to test interventions aimed at reducing the intake of sugar-sweetened drinks in order to reduce risks of obesity and related diseases. A second study focused on the impacts of sugar-free or sugar-sweetened beverages on body weight in children makes similar recommendations. According to the study, also published on Sept. 21 in NEJM, decreased consumption of sugary drinks might reduce the high prevalence of overweight children.

The study followed 641 primarily normal-weight children between the ages of 4 and 11 over 18 months and found that masked replacement of sugar-containing beverages with noncaloric beverages reduced weight gain and fat accumulation. Not only did the z score for BMI increase by 0.15 SC units in the sugar group, compared to 0.02 SD units in the sugar-free group, but weight increased by 7.37 kg in the sugar group, compared to 6.35 kg in the sugar-free group. Skinfold-thickness measurements, waist-to-height ration and fat mass also had significant increases in the sugar group, the study authors noted.