Kids' favorite fruit and the best way to serve it

American kids don't eat enough fruits and vegetables, but doctors say knowing what they'll like might be half the battle.

"You want to think about what kids like so then you can offer that to kids from an early age," Dr. Deena Blanchard of NYU Langone Medical Center told CBS News. "The other thing is that we know kids are more likely to try new foods if they try it with something they like."

The most popular choice: apples. A study published Monday in the journal Pediatrics found apples account for about 19 percent of all fruit eaten by children and teens between the ages of two and 19 years old. Fruit juice was next most popular, followed by bananas and melon. The study is based on data from more than 3,100 kids from the National Health and Nutrition Examination Survey between 2011 and 2012.

The study also found about a third of children's fruit consumption came in the form of 100-percent juice drinks. But doctors say juice alone doesn't have the same health benefits as eating whole fruits. Drinking juice has also been shown to contribute to weight gain.

"You are not getting the fiber that you are getting with eating a whole piece of fruit," Blanchard said. The American Academy of Pediatrics advises against giving juice to infants; for toddlers it recommends primarily drinking water or milk, and limiting fruit juice to no more than 4 to 6 ounces a day.

The advice makes sense to mom Danielle Kilarjian. She says apples are a favorite snack for her kids.

"It's really healthy it's a great snack option for them instead of all the processed stuff, " she told CBS News. "My daughter, Charlie, will get peanut butter on her apple, so it's added protein which is great."

The American Academy of Pediatrics says that offering fruit often, as a snack or part of meals, can make a big difference in encouraging kids' healthy diets. They advise adding fruit to cereal or a child's lunch box, or including vitamin C-rich fruits in meal preparation.

Parents eating more fruits themselves can also serve as a role model for kids.