Preschool children 2 years and older should spend no more than two hours a day watching television and using the computer. That's according to recommendations from the American Academy of Pediatrics (AAP). But research at the Childrens Nutrition Research Center (CNRC) in Houston, Texas, shows that many preschoolers exceed these recommendations, and the extra time spent in sedentary activity may be detrimental to their health.
The center is operated by the Agricultural Research Service (ARS) jointly with the Baylor College of Medicine in cooperation with Texas Children's Hospital. ARS is the U.S. Department of Agriculture's chief scientific research agency.
Led by pediatrician and behavioral scientist Jason A. Mendoza, the CNRC study used the National Health and Nutrition Examination Survey that surveyed a diverse group of more than 1,800 preschoolers, ages 2-5, concerning their media consumption or screen time, measured as TV/video viewing or computer use. Researchers compared children watching more than two hours of TV/videos to those watching two hours or less, and computer users to nonusers, relative to various selected health outcomes related to obesity.
Results showed that 30.8 percent of the preschoolers studied exceeded the AAP guidelines just by watching television, not including computer time. Most watched one to three hours of TV or video on the assessment day. Those children who surpassed the AAP recommendations on TV/video viewing were more likely to be overweight or at risk for being overweight.
Children's computer use also correlated to higher body fat but was not related to weight status, possibly because of the relatively small number of preschoolers who used computers during the research period.
Reasons for obesity observed among the children exceeding AAP recommendations include substituting TV/video watching for physical activity; watching television ads that encourage consumption of unhealthy, fatty foods; and snacking while watching TV/videos.
These findings were published in a 2007 issue of the International Journal of Behavioral Nutrition and Physical Activity. They showed that additional research is needed to determine how screen time affects young children's weight and body fat. Intervention studies to reduce screen time are recommended to find ways to prevent and treat overweight preschoolers.