Cutting kids’ TV and computer time by half reduced the amount of food they ate and helped them lose weight, a new study found.

The finding offers hope to the problem of childhood obesity in the United States, where an estimated 16 percent of children ages 6 to 19 years old are overweight, a 45 percent increase in one decade, according to federal researchers.

For the study, a professor in the department of pediatrics and social and preventive medicine at the University at Buffalo,  and his colleagues studied 70 overweight children, aged 4 to 7, who watched TV or played computer games for at least 14 hours a week.

The researchers installed a monitoring device on each television and computer the child used; the device allowed for the reduction of the children’s weekly screen time by 10 percent a week until a 50 percent reduction had been reached. Each family member was given a unique code to activate the TV or computer. In addition, the kids received such incentives as money and stickers to spend less time with TVs or computers.

The other overweight children had no restriction on their use of TVs or computers.

Professor‘s team found that the children who had no restrictions on their computer or TV use reduced their TV watching or computer-games playing by 5.2 hours a week. But the kids with restricted use cut their TV and computer time by 17.5 hours a week.

And, the children with restricted TV and computer time lost more weight than the other children. However, the researchers found no difference between the two groups in terms of physical activity.

“Using technology to modify television viewing eliminates parental vigilance needed to enforce family rules and reduces the disciplinary action needed if a child exceeds his or her sedentary behavior limits,” the authors concluded. “Perhaps most important, the device puts the choice of when to watch television in the child’s control, as opposed to a rule such as ‘no television time until homework is completed.'”