"Juice is definitely a part of this," said lead researcher Jean Welsh of the Centers for Disease Control and Prevention.
While fruit juice does have vitamins, nutritionists say it's inferior to fresh fruit.
She said preschoolers were better off snacking on fruit or drinking water.
Welsh's research, published in the February issue of Pediatrics, found that for 3- and 4-year-olds already on the heavy side, drinking something sweet once or twice a day doubled their risk of becoming seriously overweight a year later.
The Pediatrics study followed 10,904 Missouri children in a nutrition program for low-income families. Researchers looked at the effect of sweet drinks in three groups: normal and underweight children, those at risk of becoming overweight, and those who already were overweight.
The researchers compared the children's heights and weights, approximately one year apart. They also looked at parents' reports of what their children ate and drank during a four-week period at the beginning of the first year. Fruit drinks like Kool-Aid and Hi-C were included as sweet drinks, along with juice and soda.
The children in the study drank, on average, more fruit juice than soft drinks or sweetened fruit drinks.
The authors suggest that limiting sweet drinks may help solve the growing problem of childhood obesity. One in five American children is overweight, according to the National Institutes of Health.
Dr. Rebecca Unger, who evaluates overweight children in private practice and at Children's Memorial Hospital in Chicago, said the study backs up what she sees in the real world.
"We do see kids do well when we cut out juice," she said. "Sometimes that's all they need to do."
Journal Pediatrics & cdc.gov 2/7/05
Steve - Of course, this study comes as no surprise to us, or should it to you. What is very exciting is the indictment of fruit juice. For years, we have been tirelessly telling our clients that fruit juice is not an alternative to soda. For the reasons mentioned above, it can be just as detrimental for weight gain and blood sugar imbalance. There are so many fun drink alternatives. Kids love unsweetened fruit-flavored waters, sparkling or flat. If you need to sweeten them, add a bit of stevia extract (a safe, herbal, non-glycemic, non-caloric sweetener).