Children's intake of sugar-sweetened drinks -- soda pop, sports drinks, "juice drinks," iced teas, lemonades and punches -- has surged in recent decades, in lockstep with the rise in childhood obesity.
In the March issue of Pediatrics, researchers from Children's Hospital Boston report that a novel intervention to limit consumption of sugary drinks -- home deliveries of noncaloric beverages -- had a beneficial effect on weight loss.
Release of the study brought an immediate reaction from consumer advocates who have been working to reduce teens' soda intake.
The report "provides dramatic evidence that the empty calories in soda and noncarbonated soft drinks promote weight gain in overweight teenagers," said Michael F. Jacobson of the Center for Science in the Public Interest.
"If the soft drink industry had any respect for children's health, it would extend its recent pull-out from elementary schools and remove soda, 'sports' drinks, and other high-calorie beverages from middle and high schools," Jacobson said.
"School boards and legislatures that haven't ejected soda from all schools already should see this study as another compelling reason why they should do so. The small profit that schools earn from soda sales does not justify a practice that causes health problems in students," he said.
About the Study
The randomized, controlled trial, led by Cara Ebbeling, PhD, and David Ludwig, MD, PhD, in the hospital's Division of Endocrinology, enrolled 103 children aged 13 to 18 through a Boston area high school. The teens were offered a $100 mall gift certificate if they stuck with the six-month study, and all did.
Half the teens, picked at random, received weekly deliveries of noncaloric beverages of their own choosing -- bottled waters and artificially-sweetened drinks. They were instructed to avoid sugar-sweetened beverages and advised on how to choose noncaloric drinks outside the home. Monthly phone calls and refrigerator magnets ("Think Before You Drink") provided reminders.
The remaining teens, serving as a control group, were asked to continue their usual eating and drinking patterns.
At the end of six months, the group receiving beverage deliveries had an 82 percent reduction in consumption of sugary drinks, while intake in the control group remained unchanged. The heavier the teen was initially, the stronger the effect on body weight.
Among the heaviest one-third of teens, the beverage-delivery group had a marked decrease in body mass index (BMI), while the control group had a slight increase -- a group-to-group difference of almost 1 pound per month. Other factors affecting obesity -- physical activity levels and television viewing -- did not change in either group.
Ebbeling calculates that a single 12-oz sugar-sweetened beverage per day translates to about 1 pound of weight gain over 3 to 4 weeks.
"No Nutritional Value"
"Sugary beverages have no nutritional value and seem to make a huge contribution to weight gain," she says.
Comprehensive weight-loss programs often do not have a substantial effect on body weight, Ebbeling adds. "People often get overwhelmed by nutrition advice and give up," she says. "We opted to study one simple, potentially high-impact behavior, and made it easy for adolescents to replace sugary drinks with noncaloric beverages."
Although the intervention targeted only the home environment, previous research suggests that home is where adolescents get the majority of their food and beverages.
"It should be relatively simple to translate this intervention into a pragmatic public health approach," the authors comment. "For example, schools could make noncaloric beverages available to students by purchasing large quantities at low costs."
