Kids under the age of 1 should avoid fruit juice, older kids should drink it only sparingly and all children should focus, instead, on eating whole fruit, according to the American Academy of Pediatrics.
The pediatricians' group previously advised against giving fruit juice to infants under 6 months, but expanded that recommendation given evidence linking juice consumption to tooth decay and to gaining too much or too little weight.
For older kids who are at a healthy weight, 100 percent juice is fine in moderation, but should make up less than half of the recommended fruit servings per day, the AAP says.
"We want to reinforce that the most recent evidence supports that fruit juice should be a limited part of the diet of children," says Steven Abrams, a professor of pediatrics at Dell Medical School at the University of Texas at Austin, and an author of the guidelines, which were published Monday in Pediatrics.
Whole fruit is a much better way to get all the vitamins and nutrients of fruit, the guidelines say. Whole fruit contains fiber, which slows the absorption of sugar by the body, and it also makes you feel fuller than juice, which can prevent overeating.
According to data from the Centers for Disease Control and Prevention, between 2003 and 2010 kids ate an increasing amount of whole fruit and drank less juice. But 60 percent of kids were still not getting their recommended servings of fruit, which is 1 to 2 cups, depending on age, gender and level of activity.
"I think there's still a prevailing notion among some parents that juice is a reasonable substitute for fruit," says Mark DeBoer, an associate professor of pediatric endocrinology at the University of Virginia School of Medicine, who was not involved in the report.
Kids who do drink juice should cap their consumption at 4 ounces per day for toddlers, 4 to 6 ounces for kids 4 to 6 years old and 8 ounces for children from 7 to 18, the guidelines say. The best ways to meet a child's fluid needs are water and low-fat milk, says Abrams.
DeBoer says he would prefer that kids meet their fruit requirements entirely through whole fruit, especially those who are above a healthy weight. His research suggests an association between consistent juice consumption at age 2 and higher odds of becoming overweight by age 4.
Of course, correlation doesn't mean causation, and childhood obesity is unlikely to be caused – or prevented — by a single factor.
These new guidelines don't apply to fruit drinks, which contain less than 100 percent juice and have added sweeteners. Those fall into the category of sugar-sweetened beverages, along with soda, sports drinks and energy drinks, and frequent consumption is associated with poor health outcomes, according to the CDC. An exception is that sports drinks may be useful for child or teen athletes who are exercising heavily, the AAP said in a 2011 clinical report.
Smoothies, too, fall into the "treat" category, says Abrams.
The guidelines also strongly discourage unpasteurized juice products, which can carry pathogens such as E. coli.
There is some evidence that 100 percent orange juice is associated with better health outcomes in adults, but it's not known if there's a comparable benefit for kids and teens.
And what about kids who won't eat fruit? "It's fundamentally sweet," says Abrams. "There aren't too many kids who can't find a fruit they like." It may take many exposures, though – one 2003 study found that, at least with vegetables, daily tastes over two weeks improved kids' acceptance.
Katherine Hobson is a freelance health and science writer based in Brooklyn, N.Y. She's on Twitter: @katherinehobson.