(CBS) Allowing your child lots of television time might not seem like such a big deal when they're toddlers. But the side effects of too much TV watching may not emerge until your child hits grade school, according to a report in the May issue of Archives of Pediatrics & Adolescent Medicine, one of the JAMA/Archives journals.
Children exposed to more television at 29 months of age appear to have more problems in school and poorer health behaviors when they reach the fourth grade.
Linda S. Pagani, Ph.D., of Université de Montréal, Canada, and colleagues studied 1,314 children of about 29 months of age whose parents reported their weekly hours of TV watching.
Each additional hour of television in early childhood responded to a 7 percent unit decrease in classroom engagement, 6 percent unit decrease in math achievement and 13 percent unit decrease in time spent doing weekend physical activity.
At the same time, for each additional hour of TV watching in early childhood, research showed 9 percent higher scores for consumption of soft drinks and 10 percent higher scores for consumption of snacks, as well as a 5 percent unit increase in BMI.
Television watching toddlers showed 10 percent increase in classmate victimization at the fourth grade.
"The long-term risks associated with higher levels of early exposure may chart developmental pathways toward unhealthy dispositions in adolescence," Pagani and her colleagues stated.