-- Caffeine is a stimulant that is found naturally in some foods and is added to others.
It can trigger a fast heartbeat, headache, digestive problems, high blood pressure, moodiness and insomnia, the National Safety Council says.
Children may wind up feeling more of caffeine's effects than adults, since presumably kids don't consume as much and their bodies haven't built up as much of a tolerance as adults have.
Here is the agency's list of what caffeine doesn't do for kids:
Quench kids' thirst. In fact, caffeine is a diuretic and will cause consumers to urinate more without re-hydrating.
Provide nutrition that children need. And there's some evidence that caffeine affects how calcium is absorbed, which may lead to accelerated bone problems.
Provide real energy. Caffeine may make a user feel more awake, but it doesn't give a person real energy, the agency says. In fact, it may trigger insomnia and make a person feel more tired the next day. Kids should find energy in eating nutritious foods, the council says.