In the past 30 years, obesity rates have tripled among preschool-aged children and quadrupled for elementary-aged children. A number of studies link a high body mass index (BMI) with frequent television watching and the most obvious — and widely believed — explanation is that television viewing is a sedentary activity. However, a 2009 study published by the American Journal of Public Health suggests that the connection between TV and child weight problems actually relates to the content of the programming.

In “Associations of Television Content Type and Obesity in Children,” researchers followed children from 1997 to 2002 to see the effect of different types of television on obesity rates. After controlling for other possible contributing factors — such as eating while watching TV, physical activity during other parts of the day, and race/ethnicity — the researchers concluded that “television advertising, rather than viewing per se, is associated with obesity.”

The study’s findings include:

• Viewing of commercial television was significantly associated with higher BMI across all ages and even after controlling for all other factors.
• Noncommercial television had no statistically significant association with obesity.
• From 1997 to 2002 the time spent watching noncommercial television decreased while commercial television increased.
• Food is the most commonly advertised product on children’s television. Children see an average of 4,000 television commercials for food each year, or about 30 hours’ worth.
• During Saturday morning cartoons, children see an average of one food ad every 5 minutes.
• 95% of foods commonly advertised on television are of poor nutritional value.

The researchers state that the increased obesity of children watching such programs “probably operates through the effect of advertising obesogenic foods,” and suggest further investigation of content of television advertisements.

Tags: children, obesity, technology, exercise