Banning fast food advertisements in the US could reduce the number of overweight children by 18 percent, said the researchers from the National Bureau of Economic Research (NBER).
The study, published in this month in the Journal of Law and Economics, adds to an ongoing debate in the food industry about child-directed food and drink advertising and childhood obesity.
Although it relates to fast food, voluntary action is already being taken by companies including Nestle and Dannon, which have signed up to a self regulation scheme to ensure products marketed towards children meet nutritional standards.
NBER economists Shin-Yi Chou of Lehigh University, said: “We have known for some time that childhood obesity has gripped our culture, but little empirical research has been done that identifies television advertising as a possible cause.
“Hopefully, this line of research can lead to a serious discussion about the type of policies that can curb America's obesity epidemic.”
The paper measured the number of hours of fast food television advertising messages viewed by children on a weekly basis.
It found that a ban on fast food ads during children's programming would reduce the number of overweight children aged three-to-11 by 18 percent, and lower the number of overweight adolescents aged 12-18 by 14 percent. The effect is more pronounced for males than females.
However, the authors questioned whether such a high degree of government involvement, and the cost of such policies, was practical.
The researchers also suggested the elimination of the tax deductibility of food advertising costs, which would be equivalent to increasing the price of advertising by 54 percent.
It said this would reduce fast food advertising messages by 40 percent for children, and 33 percent for adolescents.
The study, based on the viewing habits of nearly 13,000 children using US Department of Labor data, claims to be the largest of its kind to directly tie childhood obesity to fast food advertising on American television.
A 2006 report issued by the Institute of Medicine indicated there is compelling evidence linking food advertising on television and increased childhood obesity.
Co-author, Michael Grossman of City University of New York Graduate Center, said: “Some members of the committee that wrote the report recommended congressional regulation of television food advertisements aimed at children, but the report also said that the final link that would definitively prove that children had become fatter by watching food commercials aimed at them cannot be made.
“Our study provides evidence of that link.”
The Centers for Disease Control estimate that, between 1970 and 1999, the percentage of overweight children aged 6-11 more than tripled to 13 percent. Adolescents aged 12-19 also saw a significant increase, reaching 14 percent.
The NBER study was funded by the National Institutes of Health.
Source: Journal of Law and Economics Volume 51 (November 2008)
doi: 10.1086/590132 “Fast-Food Restaurant Advertising on Television and Its Influence on Childhood Obesity”
Authors: Shin-Yi Chou, Lehigh University; Inas Rashad, Georgia State University; Michael Grossman, City University of New York