In response to a rapid increase in childrens' obesity rates over the past two decades, some politicians and interest groups have called for a ban on food advertising directed at children on the argument that such advertising has contributed to the children's obesity problem.

A new study by Federal Trade Commission staff reported yesterday, however, finds that over the past 28 years there has been a significant drop in the number of food product ads viewed by children. As the Washington Post reports:

Children see significantly fewer television ads promoting food products today than they did 28 years ago, according to a new study by the staff of the Federal Trade Commission.

Today, children watch about 13 food advertisements a day on television, down from more than 18 in 1977, the agency staff said. The staff study did not address how many other food ads kids see through other kinds of promotions, including online gaming, package promotions and in-school marketing.

Overall, the drop in food ads on shows watched predominantly by children aged 2-11 was on the magnitude of approximatley 30-50%, depending on the measurement of what proportion of the audience was children. There were very large drops in children's advertising for cereal and candy products and small increases in ads for restaurants, movies, video games, dvd's, and other kinds of food such as yogurt.

The large drop in food advertising may be explained in part by the fact that much more of the television ad time today is being given over to promotional ads for other programs, as well as an increase in advertisements for products such as dvd's and video games, which either didn't exist 28 years ago or did so on a much smaller scale than today.

Moroever, my earlier research finds, somewhat surprisingly, that there has been a substantial downward trend in commercial television viewing by children during this same period, from about 4 hours a day, to a little under 3 hours, which probably explains some of the decline in viewing of ads. As parents will quickly realize, however, this drop in television viewing has been offset by a larger rise in "screen time" such as computers, video games, and dvd's and videos, such that even though kids are watching less television (and seeing fewer paid ads) they are probably engaging in more sedentary activity. This also doesn't count the important introduction of commercial-free or largely commercial-free premium cable tv such as HBO Family or the Disney Channel. There is no good evidence on the prevalence of food ads on those media.

This is the most comprehensive reseach on the question of the relationship between the purported link between food advertising and the rise in children's obesity to date. It is consistent with what some of us predicted previously that further research would likely find.

The findings were reported at a joint FTC-HHS workshop on Marketing, Self-Regulation, and Childhood Obesity. The workshop concludes today. There are call-in numbers for those who are interested in listening in to the proceedings, but cannot make it to Washington.

FTC Chair Deborah Majoras also reiterated in her remarks opening the workshop that there remains no plan for the FTC to ban food advertising on children's television, a policy decision that is reinforced by the findings reported yesterday:

In opening the workshop, FTC Chairman Deborah Platt Majoras said it would be unwise and not viable for the agency to ban children's food advertising. However, she warned, it would also be "unwise for industry to maintain the status quo. Not only is downplaying the concerns of consumers bad business, but if industry fails to demonstrate a good-faith commitment to this issue and take positive steps, others may step in and act in its stead."