NEW YORK - Trying to help children lose weight by cutting back on the time they spend in front of a TV or video game doesn't have much of an effect, according to a Canadian study.

Interventions designed to reduce overall screen time, including individual and family counseling, automatic monitoring of screen time and classroom curricula, have all been largely unsuccessful, wrote Catherine Birken of the Hospital for Sick Children Research Institute in Toronto. For the study, which appeared in the journal the Archives of Pediatrics & Adolescent Medicine, Birken and her colleagues reviewed 13 large studies involving more than 3,000 children.

The methods the studies tested were unable to help the children lose weight or watch less TV, she said.