Analysis concludes sugary drinks contribute to weight gain

People who drink sugary soft drinks do not appear to compensate by reducing calories somewhere else in their diets, so they tend to pack on extra pounds, Yale University researchers report.

Their work, published in April’s American Journal of Public Health, is based on what’s called a meta-analysis of 88 soda studies. The bottom line: People who drink sugary sodas consume more calories in a typical day than those who don’t.

This adds to the growing body of evidence that these drinks are contributing to the nation’s obesity crisis. A separate review of 30 studies, released in August by the Harvard School of Public Health, also found that soft drinks and other sugary beverages contribute to weight gain.

Although these two research papers may seem to state the obvious, experts have been debating the topic for years. On one side are nutrition researchers who say soft drinks add weight because they are high in calories and don’t make people feel full and satisfied.

On the other side are other researchers and beverage industry representatives who say people can enjoy all kinds of drinks as part of a healthful diet. They say many things contribute to weight gain, including sedentary lifestyles.

This issue is particularly important as schools re-evaluate what they offer in their vending machines.

Other findings from the Yale study

Soda drinkers consume less milk and have slightly lower intakes of calcium.

Soda studies funded by the industry are more likely to downplay any concerns about soft drinks.

“There is compelling evidence that soft drinks have negative effects, and so actions such as stopping their sale in schools and scaling back marketing to children are justified,” says senior scientist Kelly Brownell, director of the Rudd Center for Food Policy and Obesity at Yale.

Brownell says a 20-ounce cola contains 15 teaspoons of sugar. He says schools need to be smart and not replace sodas with sports drinks, which are also high in calories. For instance, a 12-ounce can of ginger ale has about 140 calories; a 12-ounce bottle of lemon-lime Gatorade has 90 calories.

Richard Forshee, director of research for the Center for Food, Nutrition and Agriculture Policy at the University of Maryland, says there have been three other recent reviews that found weak evidence of a link between soft drinks and weight gain.

“The association that may exist is not large,” he says. “Calories do matter, and soft drinks have calories, so you need to drink them in moderation and as part of a balanced diet.”

Richard Adamson, a scientific consultant for the American Beverage Association, says another large international study, not mentioned in the Brownell review paper, showed no association between soda consumption in youth and weight gain. If you don’t expend the calories you consume, it can result in weight gain, no matter where those calories come from, he says. “It’s not what’s in the can – whether it’s juice, soft drinks or milk – it’s what’s on the couch.”

Barry Popkin of the University of North Carolina says this new study should help schools decide what to offer students. “What we need in school vending machines are water, skim milk and 1 percent-fat milk.”

He advises school districts to stop stocking vending machines and school stores with sodas, sports drinks and flavored, sweetened milks. “All of these provide excessive extra calories and feed our growing child and adolescent obesity problem,” he says.