That's according to new research published in the New England Journal of Medicine.
In people with a high genetic risk for obesity, getting a lot of sugar from sugar-sweetened drinks may amplify the genetic effects on obesity, says researcher Lu Qi, MD, PhD, an assistant professor of nutrition at the Harvard School of Public Health.
Qi's study and two others looked at the effects on weight gain of sugary drinks -- including sodas, fruit punches, lemonades, or other fruit drinks.
The new research should inspire people to give up sugary drinks or consider them an occasional treat, says David Appel, MD. Appel is the director of the Montefiore Medical Center School Health Program and associate professor of clinical pediatrics at Albert Einstein College of Medicine.
"These three studies give very clear evidence that drinking sweetened beverages even in modest amounts clearly results in increased weight and excess weight," he says.
In a statement, the American Beverage Association countered: "We know, and science supports, that obesity is not uniquely caused by any single food or beverage."
Sugary Drinks and Genes
Evidence is already strong, Qi says, that sugary drinks are linked with weight gain.
His team wanted to look at whether the effect of sugary drinks differs depending on individual genetic risk for obesity.
Qi's team looked at more than 33,000 people and calculated a genetic-risk-for-obesity score.
The genetic risk scores ranged from 0 to 64.
For every 10 points on the genetic risk score, those who had the fewest sugary drinks had a 35% higher risk of obesity, he found. This group had less than one sugary drink a month.
For every 10 points on the genetic risk score, those who had the most sugary drinks, one or more a day, had a 235% higher risk of obesity, he found.
"If you reduce your intake of sugary beverages, your genetic risk of obesity may be lessened," he says.
His research found a link between sugary drinks, genetic risk, and excess weight, not cause and effect.
Qi received funding from Amgen for the study.