America's Children, Supersized

Does Television Advertising Matter?

C

hildhood obesity around the world, and particularly in the United States, is an escalating problem that has received much attention of late. In less than thirty years, the prevalence of overweight children and adolescents in America has more than doubled. In the 1963–70 period, 4 percent of children ages 6–11 years and 5 percent of adolescents ages 12–19 were defined as being overweight. The percentage of children who are overweight more than tripled by 1999, reaching 13 percent. For adolescents, the incidence of overweight has nearly tripled in the same period, reaching 14 percent.

An overweight child or adolescent is defined as one having a BMI at or above the 95th percentile based on age- and gender-specific growth charts. Obesity puts children at risk for a range of health problems and can affect cardiovascular health, the endocrine system, and mental health. The probability of childhood obesity persisting into adulthood is estimated to increase from about 20% at 4 years of age to approximately 80% by adolescence.

Some estimates suggest that the increasing prevalence of overweight and obesity accounts for approximately 300,000 deaths every year, next only to the preventable mortality associated with cigarette smoking (McGinnis and Foege 1993; Allison et al. 1999). In a more recent study, Flegal et al. (2005) report a smaller but still substantial figure of approximately 112,000 excess deaths in the year 2000. Aggregate medical spending for the United States that is attributed to obesity accounted for 9.1 percent of total annual medical expenditures in 1998, as high as $78.5 billion (Finkelstein et al. 2003).

Finding the causes of this dramatic increase in obesity among children and adolescents is an important input in designing prevention policies. On the simplest level, weight gain is caused by more energy intake than energy expenditure over a long period of time. The problem of energy imbalance is not purely due to genetics, since our genes have not changed substantially during the past two decades. Researchers have tended to focus on environmental factors such as the availability of fast food to promote high energy intake as well as the appeal of television, video games, and computers to discourage energy expenditure.

Television viewing may contribute to childhood obesity both by reducing energy expenditure from displacement of physical activity and increasing energy intake from increased snacking during television viewing or as a result of exposure to food advertising.

How the commercial advertising of foods contributes to the epidemic of obesity among children and adolescents is still an ongoing debate. There is widespread speculation that the exposure to food advertising may contribute to unhealthy food choices and weight gain. Despite lacking evidence showing the direct linkage between television food advertising and childhood obesity, several industrialized countries such as Sweden, Norway, and Finland have banned commercial sponsorship of children’s programs. Sweden also does not permit any television advertising targeting children under the age of 12.

In the United States, most recently, companies such as Kraft Foods have decided to curb advertising aimed at children in an effort to encourage better eating habits. The Institute of Medicine 2006 report entitled Food Marketing to Children and Youth: Threat or Opportunity indicated that there is compelling evidence linking food advertising on television and increases in childhood obesity. 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.

The investigation of the causal relationship between fast-food restaurant advertising and body weight among children and adolescents is important when forming policies to cope with the rapid increase in obesity rates. In my study with Michael Grossman, who is a distinguished professor of Economics at the City University of New York Graduate School and Inas Rashad Kelly, who is an assistant professor of Economics at the Queens College of the City University of New York, we explore this causal relationship between exposure to fast-food restaurant advertising on television and childhood obesity.

To evaluate this causal relationship , we employ two individual-level data sets: the National Longitudinal Survey of Youth 1997 for adolescents ages 12–18 and the Child–Young Adult National Longitudinal Survey of Youth 1979 for children ages 3–11. The data for fastfood restaurant advertising on television from the Competitive Media Reporting are appended to the individual-level data by metropolitan area and year. We employ several different specifications, and most results show a positive and statistically significant impact of fast-food restaurant advertising on television on body mass index and on the probability of being overweight for children and adolescents.

Based on our estimations, a ban on these advertisements would reduce the number of overweight children ages 3–11 in a fixed population by 18 percent and would reduce the number of overweight adolescents ages 12–18 by 14 percent. The elimination of the tax deductibility of this type of advertising would produce smaller declines of between 5 and 7 percent in these outcomes but would impose lower costs on children and adults who consume fast food in moderation because positive information about restaurants that supply this type of food would not be completely banned from television.

Clearly, we have not provided enough information to fully evaluate the two policies just discussed. Indeed, we have not addressed the larger issue of whether the government should intervene in the food purchase decisions of its citizens. In the case of children, one justification for government intervention is that society as a whole may reap substantial current and future production and consumption benefits from improvements in children’s health. The case is strengthened because overweight children are extremely likely to become obese adults and because children are less likely to have information about the consequences of their actions or to heavily discount these consequences. The case is weakened because parents may more easily and immediately affect the choices made by their children than can the government.

In addition, one would need to consider the degree of government involvement that is merited and the costs of alternative policies if some intervention appears to be worthwhile. Hence, more research is required to evaluate the effectiveness of these policies and others. Our study should be viewed as one of many inputs in this process.

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