Drinks containing caffeine can significantly affect children's behaviour, report scientists in the US, who studied the sleep patterns of teenagers consuming caffeine in food or drinks.
Researchers at Ohio State University in the US studied 191 teenagers between the age of 14 and 16 for two weeks. They related daily intake of caffeinated drinks and foods to age, sex, sleep characteristics and day of week.
In the 191 students studied, caffeine intake ranged between 0 and 800 mg daily. Mean use over two weeks ranged up to 379.4 mg and averaged 62.7 mg daily. Boys were found to consume more caffeine than girls.
They found that those with higher caffeine intake suffered disrupted sleep, increased wake time after sleep onset and increased daytime sleep.
"Regardless of whether caffeine use disturbed sleep or was consumed to counteract the daytime effect of interrupted sleep, caffeinated beverages had detectable pharmacologic effects. Limitation of the availability of caffeine to teenagers should therefore be considered," concluded the researchers.