All we ever needed to learn, we learned in kindergarten, author Robert Fulghum reminded us a quarter-century ago.

Among imperatives for the nation's five-year-olds were playing fair, not hitting people and, when you do, saying you're sorry. Wash your hands before you eat and remember to clean up your own mess. Unfortunately, however, many kindergarteners today are learning a new habit, one not advised by Fulghum or generations of mothers dating back to the 19th-century introduction of bottled soda: the daily consumption of beverages loaded with sugar.

Researchers at the University of Virginia in Charlottesville find that many children born in 21st-century America consume at least one soda, sports drink, or sugar-sweetened fruit juice every day, depending on age. In a representative sampling of 9,600 children ages two, four, and five, nine to 13 percent of children downed at least one sugar-laden beverage per day.

Those kids were also more likely to be supervised by an overweight mother and to watch at least two hours of television per day by ages four and five. Until now, the link between sugary drinks and obesity had been proven only among teenagers and adults, with findings for young children in doubt.

"Even though sugar-sweetened beverages are relatively a small percentage of the calories that children take in, that additional amount of calories did contribute to more weight gain over time," study leader Mark DeBoer told reporters.

In a study published Monday in the journal Pediatrics, DeBoer and his colleagues weighed the children and their mothers on multiple survey visits, and then corrected for confounding factors, such as socioeconomic status. They found that five-year-olds who downed at least one sugary beverage per day were more than 43 percent more likely to be obese than those who consumed fewer of the drinks or not at all.

Approximately 15 percent of the kindergarteners in the study were obese, meaning a body mass index higher than the 95th percentile for their age and sex, as defined by the U.S. Centers for Disease Control and Prevention.

Naturally, the American Beverage Trade Association took issue with the findings, asserting that obesity among young children may be caused by multiple factors. "Overweight and obesity are caused by an imbalance between calories consumed from all foods and beverages and calories burned physical activity," the trade group told Reuters on Monday.

"Therefore, it is misleading to suggest that beverage consumption is uniquely responsible for weight gain among this group of children, especially at a time in their lives when they would normally gain weight and grow."

However, DeBoer and his colleagues say that children who drink sugary beverages may simply consume more calories than others, given that sugary beverages wouldn't satiate appetite as well as foods with protein and fat. But drinking a glass of milk with dinner "will contribute to satiety and not as big of an increase in total intake as something that is pure sugar," DeBoer said.

Other researchers said they were not surprised by the findings, and recommend that parents make sugary drinks a rare treat, rather than a forbidden fruit.

Source: DeBoer M. Sugary Drinks Linked To Obesity In Young Children. Pediatrics. 2013.