Sedentary behavior, such as watching television and playing computer video games, has been the bane for years of parents of overweight children and physicians trying to help those children lose pounds. There has been little research on the effect of limiting those activities, however.


University at Buffalo researchers now have shown in a randomized trial that by using a device that automatically restricted video-viewing time, parents reduced their children's video time by an average of 17.5 hours a week and lowered their children's body-mass index (BMI) significantly by the end of the two-year study.


"Results showed that watching television and playing computer games can lead to obesity by reducing the amount of time that children are physically active or by increasing the amount of food they consume as they as engaged in these sedentary behaviors."


The study involved 70 boys and girls between the ages of four and seven whose BMI was at or above the 75th percentile for age and sex. Eighty percent of the children were above the 85th percentile, and nearly half were above the 95th percentile.


Each family member had a private individual code to activate the electronic devices. Devices in "intervention" homes had a set weekly time limit, which was reduced by 10% per week until viewing time was reduced by 50%. Children had to decide how to "spend" their allotted viewing hours.


Body mass index, caloric intake and physical activity were monitored every six months. Data were collected on socioeconomic status and characteristics of the neighborhood, including distance to parks, neighborhood activities and perceived neighborhood safety.


Changes in BMI between groups were statistically significant at six months and 12 months but became more modest over time, results showed. The intervention group showed a steady decline in BMI over the two years, while the control group showed an increase followed by a steady decline.


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