Researchers at the Harvard School of Public Health have found that limiting the amount of time overweight kids spend watching TV and playing video games can help them lose pounds.

The study involved 70 children ages 4-7 whose body mass index (BMI) was at the 75th percentile or higher. About half had their screen time limited by an electronic device hooked up to their TVs and computers. The kids who used the special blocker cut their screen time by 17.5 hours per week, compared to a decrease of only 5.2 hours per week in the control group. Less time in front of the TV also translated to a measurable decrease in BMI.

While the outcome may not surprise you, the reason for the weight loss might. Researchers found that there was no significant difference in the amount of physical activity between the groups. Instead, they saw that kids who had limits consumed, on average, 150 calories less per day. It's not that they were moving more -- it's that they were eating less.

Gadgets similar to those used in the study are already on the market and retail for under $100. Family Safe Media offers a number of TV time management tools for helping children manage their screen time. As the discussion sparked by Christina's recent posts demonstrated, parents' opinions vary widely about how much TV is ok, but this technology might be useful for parents who want to place limits.

(And here's hoping that my spouse doesn't think this is the perfect solution for my own stay-up-late-at-the-computer habit.)