This systematic review explored the literature considering the effects of caffeine on cognition, behaviour, mood and exercise performance in children and included randomised controlled trials and observational studies. The review found that at lower doses caffeine had no adverse effects upon children, but higher consumption was associated with increased risk of anxiety and symptoms related to withdrawal.
The review concluded that children and adolescents should limit daily caffeine consumption to 2.5 mg kg–1 body weight day–1 . Tea was proposed to be the most advisable source of caffeine for children due to lower caffeine content that coffee. Caffeinated soft drinks have a higher caffeine content and frequently contain added sugar. Tea may confer additional benefits through the delivery of bioactive compounds such as flavonoids.