In a study of 1,300 children by Michigan and Montreal universities, experts found that the more TV a toddler watches, the more likely they are to do badly at school and have poor health by age 10, the BBC reports. Ill effects on older kids rose with every hour of TV watched as a toddler, contributing to worse performance at school and more junk food consumed. Part of the Quebec Longitudinal Study of Child Development Main Exposure, the study asked parents how much TV their kids watched at 29 months and 53 months; on average; two-year-olds watched just under nine hours per week, while four-year-olds watched just under 15 hours. When revisited at age 10, teachers assessed the children’s academic performance, behaviour and health, and body mass index was measured. Higher level of TV viewing at age two was linked to lower level of engagement in the classroom and poor performance in math, as well as a decrease in physical activity and increase in the consumption of soft drinks and body mass index.