Experts say 100-percent fruit juice is full of vitamins and minerals, and a single serving is fine. However, large amounts of fruit juice, they say, can cause some unwanted effects.

A recent policy statement from the American Academy of Pediatrics focuses on the harmful effects of the overuse of juice for infants and children.

The statement notes the big difference between fruit drinks and 100-percent fruit juice. Fruit drinks look and taste like juice but actually contain more water and sugar than juice.

A Little Is Enough

One serving of 100-percent juice along with a serving of whole fruit can meet the dietary guideline for a child under age 7.

Still, even 100-percent juice contains high amounts of natural sugar and can cause problems if it starts to replace milk or other foods in a child's diet.

The study shows some of the ill effects of juice misuse in children, including diarrhea, gas, bloating, cavities, weight gain, certain nutritional deficiencies and even stunted growth.

"Ideally, milk and water should be served regularly, especially at meal times," said Gail Hanula, an Extension Service nutrition specialist with the University of Georgia College of Family and Consumer Sciences. "Drinking tea and soft drinks gives too few nutrients for the calories they contain."

'It'll Spoil Your Dinner'

Sometimes children will fill up on juice before a meal and then won't eat as much food or drink as much milk. This can lead to problems, because children need to eat a balanced diet from all five food groups, not just juice.

Hanula warns parents, however, to be careful when they cut back their child's juice intake. "It's so important in the hot summer," she said, "that children be well hydrated. Juice is a much better choice (nutritionally) than soft drinks."

The best drink for children, Hanula said, is water. "It quenches the thirst and is really the best fluid replacement," she said.

AAP Recommendations

While keeping kids well-hydrated this summer, you can also consider the AAP recommendations on fruit juice:

• Don't give juice to infants less than 6 months old.
• Don't give juice to infants in bottles or sippy cups that allow them to drink juice all day.
• Children 1 to 6 years old should have no more than 4 to 6 ounces, or one serving, of juice per day.
• Children 7 to 8 years old should have no more than 8 to 12 ounces, or two servings a day.
• Children should eat whole fruit to meet their recommended dietary fruit intake.
• Juice isn't appropriate to treat dehydration and thirst or to manage diarrhea.
• Children should never drink unpasteurized juice.
• Health professionals should discuss the use of juice and teach parents the differences between 100-percent fruit juice and fruit drinks.