Nearly two-thirds of kids have caffeine in their diet, the CDC says. A new report from the Centers for Disease Control and Prevention found that nearly two-thirds of American children aged 2-19 have caffeine in their diet. For kids aged 2-11, goodies like brownies, cookies and pastries — called “sweet bakery products” in the report — were the top source of caffeine. “It’s the chocolate that has the caffeine,” Gounder said. “Some of this also depends on timing, if they’re having the caffeine in the evening,” Gounder said.