Since the 1960s, obesity has become one of the most significant health problems in industrialized nations. In the U.S., the percentage of obese adults increased from 13 percent in the 1960s to 32 percent in 2004. According to some estimates, 41 percent of U.S. adults will be obese by 2015 and 75 percent will be overweight or obese. The U.S. spends on an estimated $150 billion annually in health care costs attributable to obesity – more than it spends on smoking-related illnesses. Obesity is primarily a lifestyle disease resulting from excessive caloric intake and inadequate physical activity, though genetics plays a role in food metabolism, fat storage, and the tendency to overeat.
Responding to the obesity epidemic presents a conundrum for policymakers because many of the strategies designed to address obesity conflict with deeply held moral values and legal protections, as Daniel Callahan argued in his article in the Hastings Center Report. For example, banning certain types of foods, such as artificial trans-fatty acids, restricts the freedom to decide what one eats and can undermine cultural traditions associated with food. Many people object to paternalistic government control over the human diet, such as New York City’s rule prohibiting restaurants, movie theaters, and other businesses from selling sugared drinks in portions larger than 16 ounces.
Taxes on foods tend to be regressive because economically disadvantaged people spend a higher percentage of their income on food than economically well-to-do people. Food taxes can be regarded as unfair because they have a disproportionate impact on individuals who are already economically disadvantaged. Regulating food advertisements that are not inherently deceptive may conflict with legal protections for freedom of speech.
Many of the government strategies for dealing with the obesity epidemic that focus on controlling diet are not well-supported by the evidence. Although studies have shown that restrictions on portion sizes can impact caloric intake, it is not known how consumers and businesses will respond to New York City’s rules concerning the size of sugared soft drinks. Consumers might take in the same amount of sugared drinks or total calories, and businesses might circumvent the ban by offering free refills or other discounts. The impact of taxes on soft drinks is also uncertain. Economic models indicate that taxes on soft drinks may have only a marginal impact on obesity, because soft drinks represent a small percentage of caloric intake (7% or less) and taxes that are not so high as to be regressive will have only a minimal impact on consumer behavior.
The specter of a slippery slope toward increased government control over the human diet looms large in any attempt to ban, regulate, or tax specific foods or portion sizes. If the government can ban trans-fatty acids, for example, the door is open for banning other types of foods, such as processed meats, sugared drinks, potato chips, and donuts. Strategies that deal with role of the built environment in the obesity epidemic are well-supported by the evidence and do not raise troubling concerns about paternalistic interference with the human diet or regressive taxation. The built environment includes structures humans have created for housing, business, industry, recreation, education, and transportation, such as roads, sidewalks, bike lanes, open areas, single-family homes, apartments, office buildings, schools, and shopping malls. Governments can impact the built environment through zoning ordinances, urban planning, annexation rules, housing codes, and construction of roads and parks.
A systematic review, published last year in the American Journal of Public Health, of 169 studies examining the relationship between the built environment and physical activity or obesity found that 89.2% of those studies demonstrated statistical associations between the built environment and physical activity or obesity. Aspects of the built environment associated with increased physical activity or reduced obesity included parks, sidewalks, trails, recreational facilities, school playgrounds, and traffic safety. All of the studies included in these reviews were observational and did not involve controlled experiments to determine the effectiveness of interventions in the built environment. To enhance our understanding of the role of the built environment in physical activity and obesity, it is important to conduct experimental studies, such as controlled clinical trials of environmental interventions.
Some may object to government efforts to shape the built environment that restrict property rights of landowners, builders and developers, but these restrictions can be justified as necessary to promote important government aims, such as the promotion of public health and safety. Building codes can be justified to protect people from harms resulting from poorly constructed or designed buildings. Requiring that a home have a sidewalk in front of it is no different, in principle, from requiring that it have railing on entrance steps higher than 30 inches, since both measures are designed to protect or promote human health. A zoning law that promotes the development of schools and businesses within walking distance of homes is no different, in principle, from a law that prohibits factories from being built near schools.
While it is still important for policymakers to consider strategies for addressing the obesity epidemic that focus on caloric intake, strategies that focus on making the built environment more conducive to physical activity should be given a high priority because they do not restrict freedom in objectionable ways or constitute regressive taxation. Instead of limiting or controlling choices, they enhance one’s ability to make healthier choices: a person can choose to walk to work, enjoy a park, or take the stairs instead of the elevator, even when they are not required to do so.
David B. Resnik, JD, PhD, is a bioethicist at the National Institute for Environmental Health Sciences. This article is the work product of an employee or group of employees of the National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH). However, the statements, opinions or conclusions contained therein do not necessarily represent the statements, opinions or conclusions of NIEHS, NIH, or the United States government.