Too much TV is not good for children. But how much is that?

Kindergartners and first-graders who watched as little as one hour of television a day were more likely to be overweight or obese compared to children who watched TV for less than 60 minutes each day, according to a study presented at the Pediatric Academic Societies (PAS) annual meeting in San Diego.

Efforts to fight the childhood obesity epidemic have focused on getting kids to be more active. Previous studies have shown that children who watch a lot of TV are at risk for being overweight. However, studies have not looked specifically at the link between TV watching and obesity among kindergartners.

For this study, researchers analyzed data from the Early Childhood Longitudinal Survey of 11,113 children who were in kindergarten during the 2011-2012 school year. As part of the study by the National Center for Education Statistics, lifestyle factors that could affect a child’s educational performance were collected from parents, including the number of hours of television children watched on weekdays and weekends, and how often they used computers. In addition, children’s weight and height were measured. A year later, almost 98 percent of the children initially enrolled had their height and weight re-measured, and parents again were asked about their child’s TV habits.

Results showed that U.S. kindergartners watched an average of 3.3 hours of TV a day. In both kindergarten and first grade, children viewing as little as one hour of TV daily were 50-60 percent more likely to be overweight and 58 percent to 73 percent more likely to be obese compared to those watching less than an hour. Computer use, however, was not associated with higher weight. Furthermore, children who watched one hour or more of TV daily were 39 percent more likely to become overweight and 86 percent more likely to become obese between kindergarten and first grade.

Lead author of the study, Dr. Mark D. DeBoer of the University of Virginia/Charlottesville, said in the AAP press release on the study: “Given overwhelming evidence connecting the amount of time TV viewing and unhealthy weight, pediatricians and parents should attempt to restrict childhood TV viewing.”

The American Academy of Pediatrics (AAP) recommends limiting children and teens to less than two hours of screen time each day. Dr. DeBoer, however, said even that might be too much. “Given the data presented in this study, the AAP may wish to lower its recommended TV viewing allowances,” he said.
ACSH’s Dr. Gil Ross had this perspective: “This is a large and as well-controlled as an epidemiological/observational study can be. However, the problem here is the author’s devotion to inferring a cause-and-effect relationship where none can be shown via this study. When he says things like ‘…overwhelming evidence connecting the amount of time TV viewing and unhealthy weight…’ he has clearly left the field of solid epidemiology and gone into the advocacy area.

Also, comparing young children to those peers who watch zero or ‘less than one hour’ of TV daily is comparing the bulk of kids to those who basically avoid watching, either on their own or, more likely, at the behest of their parents. Clearly, restricting their children’s TV viewing to less than an hour or none at all is a biomarker for other intense health-related dicta, so there’s no surprise that those kids would also be less susceptible to higher BMIs, having little to do directly with TV time. Nevertheless, the basic message remains valid: get off the couch and go outside and play to avoid becoming another obesity statistic.”