Toxic Environment

Psychologist Kelly Brownell coined the term toxic environment in 1994 to describe the obesigenic effects of our physical surroundings. Brownell argued that despite promising advances in our understanding of biological risk factors for overweight, the precipitous increase in obesity at the population level has occurred so quickly that it cannot be attributed solely to genetic factors. Instead, he proposed that the most straightforward explanation for the upsurge of obesity in the last decades of the 20th century is that the modern environment systematically promotes the consumption of unhealthy foods and discourages physical activity. The toxic environment provides a parsimonious explanation for the well-established finding that individually targeted behavioral weight-loss programs and community-based nutrition education campaigns produce modest reductions in population body weight. Proponents of the toxic environment theory predict that curbing the rising tide of obesity will require public policy changes that encourage healthful diet and exercise choices.

The Toxic Food Environment

Unhealthy foods such as ice cream, potato chips, and candy not only prey upon biological preferences for sugar and fat, but are also conveniently accessible, heartily portioned, cleverly marketed, and relatively inexpensive in the contemporary environment. These powerful influences converge to render unhealthy food choices the default option for modern consumers.

With regard to convenience, fast-food restaurants boast the 24-hour availability of high-calorie menu items, such as cheeseburgers, french fries, and sugared soft drinks. In addition, prepackaged snack foods are readily available at sites previously unrelated to food consumption, including gas stations, hospitals, and schools. Experimental paradigms highlight the surprising influence of tiny changes in the convenience and accessibility of unhealthy foods; in one study, secretaries ate nearly three times as many candies per day when candy bowls were placed on their own desks versus a desk two meters away. The pervasive influence of convenience is further illustrated by findings from a recent epidemiological survey indicating that approximately one-third of American children aged 4–19 consume fast food on a typical day.

Another facet of the toxic food environment is increasingly large portion sizes, which have expanded in tandem with national waistlines. Marketplace research indicates that typical portions of convenience foods such as bagels, hamburgers, muffins, and soft drinks surpass U.S. Food and Drug Administration serving size recommendations by two- to eight times. For example, the original Coca-Cola bottle held just 8 ounces of soft drink, while contemporary vending machines stock 20-ounce bottles. The first Hershey chocolate bar weighed just 0.6 ounces, while current versions weigh from 1.6 to 8 ounces. A growing number of experimental studies have linked increasing portion sizes to excess energy intake. In one investigation, participants who served themselves from four-liter bowls ate approximately 50 percent more nuts, chips, and pretzels than participants who served themselves from two-liter bowls.

Moreover, unhealthy foods are very heavily marketed, especially to young people. In 1998 alone, soft drink companies collectively spent $115.5 million advertising [Page 749]their products, and fast-food chain McDonald's spent more than $1 billion. In contrast, the National Cancer Institute recently spent just $1 million to promote its “5 a day” fruit and vegetable campaign. On average, American children view 10,000 food advertisements per year, most of which promote the purchase of energy-dense foods such as candy, soft drinks, sugared breakfast cereals, and fast foods. In addition to traditional advertisements, insidious guerilla marketing techniques—including product placements in television shows and video games and the placement of snack food logos on school-based athletic scoreboards—blur the line between advertising and entertainment.

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