Screen time behaviours and caffeine intake in US children: findings from the cross-sectional National Health and Nutrition Examination Survey (NHANES).

Background: Screen time (ST) behaviours, for example, television (TV) watching and computer use, among youth are associated with unhealthy eating, and these patterns track over time. A positive association between ST and TV watching with consumption of caffeinated foods and beverages has been described in national samples of children in a few European countries. The association of ST behaviours with caffeine intake has not been previously reported. We examined whether ST behaviours were associated with caffeine intake on a given day (% consumers and amount consumed) in a nationally representative sample of US children.

Methods: Data on 3421 children (ages 6-11 years) from the cross-sectional National Health and Nutrition Examination Survey 2007-2012 were used. Time spent on TV watching and computer use was determined using questionnaires. Dietary intake was assessed using a 24-hour recall by trained interviewers. Caffeine intake (mg) was estimated by using updated food and nutrient databases. Caffeine consumption was examined in relation to time spent (≥2 vs<2 hours/day) on ST behaviours.

Results: Children who watched TV ≥2 hours/day had significantly higher (~45% more) caffeine intake. Total ST or computer use was not associated with caffeine consumption in school-aged children.

Conclusion: TV watching was positively associated with caffeine intake in school-aged children, suggesting the need for continued monitoring of ST and caffeine intake behaviours in children and adolescents as well as examining the correlates of these behaviours to inform nutrition and health policies.