As childhood obesity rates continue to rise, the debate over the role of public schools in promoting healthy lifestyles has intensified. Public health advocates contend that schools can curb obesity by banning the sale of junk food and soda. Their more radical proposals include taxes on unhealthy foods and beverages and zoning regulations that prohibit certain businesses from operating near schools.
Over the last year, a number of outstanding research studies have suggested that stricter laws and government regulations fail to reduce the caloric intake of public school children in any significant way. Peer-reviewed studies published in The Archives of Pediatrics and Adolescent Medicine and Sociology of Education, to name two, found no significant relationship between obesity-related eating behaviors and the presence of soda and snack machines in public schools.
Last year, The Archives of Pediatrics and Adolescent Medicine published a study that sought to find a link between obesity and beverage consumption in schools. A team of researchers from the University of Illinois at Chicago examined the beverage intake of nearly 6,000 public middle school students in 40 states. They concluded that soda bans in middle schools did not reduce students' consumption of sugary drinks significantly.
The researchers discovered that middle school students in the study responded to the ban by purchasing different kinds of sugary drinks, like juices and sports drinks, in school vending machines. Yet, even schools that banned all sugar-sweetened beverages from campus did not reduce students' consumption of unhealthy drinks. Kids simply brought them from home.
Similarly, a study from the January 2012 issue of Sociology of Education examined junk food consumption and weight changes in nearly 20,000 public middle school students. Researchers from Pennsylvania State University found that the percentage of overweight or obese students did not rise in concert with the increased availability of unhealthy foods and snacks.
In fact, the percentage of overweight and obese students decreased as the availability of junk food increased. They were so surprised (or frightened) by the results that they delayed publication of the study for two years.
Undeterred by the results, public health activists contend that state legislatures need to tax and regulate food and beverage consumption outside of schools. Yet, these restrictions are nearly all cost and no benefit.
In a recent issue of the Canadian Medical Association Journal, a team of researchers pointed out that the consumption of unhealthy foods and drinks is inelastic. In other words, taxing certain food and beverage items may not reduce their consumption. Consumers may shift their consumption preferences to other unhealthy, non-taxed foods and drinks. This problem raises the difficulty of defining which foods and drinks should be subject to the tax.
So-called "fat taxes" and regulations are unpopular with certain consumer groups, particularly those who consume unhealthy foods and beverages in moderation and generally lead healthy lifestyles. They are also unpopular with organizations that want to purge crony capitalism from government. Without a doubt, the process of deciding which foods and beverages to tax and regulate would have more to do with political donations than science.
Additionally, there is little evidence that banning advertising or modifying land usage encourages families to adopt healthier lifestyles. Researchers have yet to establish a causal association between health outcomes and prohibitions on advertising and restaurant zoning restrictions. For example, a 2011 study published in BMC Public Health found no relationship between overweight or obese children and the proximity of fast food restaurants and supermarkets to their schools.
The bottom line is that government-imposed taxes and regulations on the consumption of unhealthy foods and beverages are not as important as the role of adults who lead healthy lifestyles and instill those values in their children.
Dr. Terry Stoops is director of education policy at the John Locke Foundation.