What Can Kids Drink?

As a general rule, Dr. Lippitt discourages just about everyone—and especially children—from drinking caffeine. "It's one more thing that disrupts sleep, which in turn makes you more susceptible to going down hard, which adds to your stress load," she says. "I limit caffeine wherever I can."

Sarah says caffeine stays in your system for seven hours on average. While she recognizes that teenagers like to convene at coffee houses, drinking caffeine in the afternoon isn't a healthy choice.

For quenching thirst, Sarah and Dr. Lippitt both believe water to be the best option, but they prefer milk to juice. "You want to keep a lid on the empty calories," Dr. Lippitt says, which, for kids under 8-years-old, means no more than 4 to 6 ounces of juice (100 percent fruit only) per day.