Adults have been studied; teens have been studied; other school-age children have been studied. And the evidence shows pretty conclusively that sugar-sweetened beverages are linked to increased risk of obesity.
But one group has not been studied so much: pre-school aged kids. In a major new study released today in the journal Pediatrics, researchers found that, yes, sugar-sweetened beverages also put such very young children at greater risk for obesity.
Specifically, researchers followed 9,600 children (in other words, a really big sample) from birth to age 5. It's this kind of "longitudinal" approach that gives this study a great deal of research power. "We were more interested in looking at children over a period of time," said lead author Mark DeBoer, in the department of pediatrics at the University of Virginia. He says they wanted to see whether those children who drank sugary drinks were more likely to gain an unhealthy amount of weight over those who didn't.
At ages 2, 4, and 5, parents of the children were interviewed in their home and asked about consumption of sugar-sweetened beverages -- defined as "soda pop (for example, Coke, Pepsi or Mountain Dew), sports drinks (for example, Gatorade) or fruit drinks that are not 100% fruit juice (for example, Kool-Aid, Sunny Delight, Hi-C, Fruitopia, or Fruitworks."
About one in ten of these 9,600 children drank one or more servings of sugar-sweetened beverages daily. Those children "were more likely to gain weight between 2 and 4 years of age than those who didn't," says DeBoer. "They were more likely to become obese over that time frame."
Not surprisingly, as time went on, the worse it got. By the time the kids hit age 5, "those who consistently drank sugar-sweetened beverages were the heaviest group," DeBoer said.
While the researchers adjusted for variables including socioeconomic status, race, television viewing habits and more, they still found a "clear linear relationship" between the amount of sugary drinks consumed and the "BMI z score," a special body mass index to assess weight in children.
In addition, children who regularly drink sugar-sweetened beverages consumer 17 to 20 percent more calories. "We also found it notable," the authors write, "that children drinking > SSB serving daily were more likely than infrequent/nondrinkers to watch >2 hours of television daily."
The authors advise parents to give children only calorie-free drinks and milk to drink to help avoid excess weight gain. In an accompanying editorial, researchers from UC San Francisco and UC Berkeley call for policy changes to cut down on sugar-sweetened beverages in young children.'
They note that more than 80 percent of U.S. school districts have policies prohibiting or limiting students' access to these drinks, there are few similar policies for pre-schools or childcare facilities. California, however, is a leader in this regard. In 2010, the California legislature passed AB 2084 which requires child care facilities to make water available during the day and prohibits serving drinks with added sugar.
These are some of the most "stringent regulations" for child care facilities right now, UCSF's Anisha Patel noted, putting the issue on the national agenda. "Hopefully it will spread across the country," she added.
Patel and co-author Lorrene Ritchie also make a case for adding limits on sugar-sweetened beverages in the U.S. dietary guidelines. "Provide concrete messages (i.e., limit your child's sugar drinks to no more than once a week) to help families" clearly understand the message, they say. They also believe the federal guidelines should "promote water as the first beverage of choice for thirst."