Could a larger waistline be a result of too much TV as a child?

As a youngster, remember your mother warning you that watching too much television would give you square eyes? That might not be true, but a new study, published today in BioMed Central's open access journal International Journal of Behavioral Nutrition and Physical Activity, has found that the more hours young children spend watching TV, the worse their muscular fitness and the larger their waist size as they approach their teens, with possible consequences for adult health.

The American Academy of Pediatrics recommends that children under the age of two should not exceed more than two hours of TV viewing a day. However, evidence suggests that an increasing number of parents now use the television as an 'electronic babysitter'. As a consequence, a research group from the Université de Montréal, Canada, set out to determine whether there is a correlation between the number of hours spent watching TV in early childhood and subsequent physical fitness in the same school-age children.

The Canadian team used participants from the Québec Longitudinal Study of Child Development, and assessed parental reports of the number of hours the child spent watching TV per week at 29 and 53 months of age. Muscle strength and abdominal fat correlate with fitness, and, were therefore measured when children were in the second and fourth grade, using the standing long jump test and waist circumference.

The authors found that each hour per week of television watched at 29 months corresponded to a 0.361 cm decrease in the Standing Long Jump Test, indicating a decrease in muscle strength. An extra hour's increase in weekly TV exposure between 29 and 53 months of age predicted an extra 0.285 cm reduction in test performance. Also significant was that waist circumference at fourth grade increased by 0.047 cm for every hour of television watched between the ages of 29 and 53 months, corresponding to a 0.41 cm increase in waistline by age 10, or a 0.76 cm increase for those who watched more than 18 hours of TV a week.

Since physical fitness is directly related to future health and longevity, increased waist size and reduced muscular strength that carries into adulthood could predict negative health outcomes later in life. The team's lead investigator, Dr Caroline Fitzpatrick from New York University who conducted this research at the Université de Montréal and Saint-Justine's Hospital Research Centre, commented, "TV is a modifiable lifestyle factor, and people need to be aware that toddler viewing habits may contribute to subsequent physical health." She continued, "Further research will help to determine whether amount of TV exposure is linked to any additional child health indicators, as well as cardiovascular health".