Children’s weekend screen habits affect BMI in adolescence

Children with heavy screen time during the weekends are more likely to have high body mass index (BMI) in adolescence, a recent study has shown.

Researchers conducted a prospective 3-year follow-up study on 5,084 children (mean age, 11±1 years; 53.3 percent female) who completed a web-based questionnaire detailing health- and lifestyle-related questions. Information about sedentary screen time outside of school hours were collected. BMI was measured at baseline and at follow-up, an average of 2.5±0.8 years later.

Most of the children (78 percent; n=3,964) were of normal weight at follow-up, while 12.3 percent were overweight, 7.6 percent were underweight and 2.1 percent were obese. Sedentary screen time increased over the same time frame.

Specifically, the proportion of heavy TV viewers jumped from 16 percent to 23 percent during school days and from 19 percent to 30 percent during weekends. At follow-up, almost half were heavy computer gamers and/or screen users during weekends, while 36 percent were such during weekdays.

These spikes in screen time had ramifications on BMI. Heavy TV viewing during weekends correlated with a significant increase in BMI z-scores 3 years later (p=0.011). The same was true for heavy computer use during weekends, though significance was achieved only in the model that did not control for BMI z-scores at baseline.

“Combining increased physically active hobbies, such as sport club activities and outdoor activities with family, and decreasing sedentary screen use among children especially on weekends may prove effective in preventing becoming overweight or obese,” the researchers said.