Unprecedented weight gain has occurred over the past two decades, such that the prevalence of overweight and obesity among youth in the United States exceeds 25%¹. Genetic factors can influence individual predisposition for obesity; however, given the dramatic increase in prevalence among genetically stable populations, the adverse effects of a “toxic environment” characterized, in part, by an overabundance of fast food and sugar-sweetened beverages likely underlies the obesity epidemic^{2, 3}. While there are no data on fast food and obesity in children, there seems to be a relationship between fast food consumption and calorie intake among adolescents^{4, 5}. Furthermore, change in body mass index was independently associated with increased intake of sugar-sweetened beverages over two years in a prospective study, such that the odds ratio for becoming obese was 1.6 for each additional serving per day⁶.

Over the last few decades, increased consumption and sales of unhealthful fast food has paralleled the rising prevalence of obesity. In the late 1970’s, children consumed 17% of their meals away from home, and fast foods accounted for only 2% of total calorie intake⁷. By the mid- to late-1990’s, the proportion of meals eaten away from home nearly doubled to 30%, and fast food intake increased to 10% of total calorie intake. Likewise, per capita daily soft drink consumption increased from 179 g to 520 g for boys and from 148 g to 337 g for girls between 1965 and 1996⁸.

It is plausible that these trends have been driven, in part, by marketing strategies of the fast food and soft drink industries. Campaigns specifically targeting children often link foods and beverages with toys, games, movies, collectibles, and educational tools⁹. Children are exposed to thousands of television advertisements per year, many for fast food and sugar-sweetened beverages^{10, 11}. Exposure to 30-second commercials increased the likelihood that young children would later select an advertised food when given options¹². Moreover, pouring rights contracts between school districts and soft drink companies permit the companies to install vending machines on school property and to sell their products at school events¹³.

Progressively larger fast food meals may be contributing to the pediatric obesity epidemic, given the relationship between serving size and calorie intake in children as young as five years of age¹⁴. Marketing strategies employed by the fast food industry offer consumers the choice to “super size” portions for an apparently minimal increase in cost over what is charged for smaller servings¹⁵. At McDonald’s Restaurant, the “super size” serving of fries (610 kcal) contains 3-fold more calories than the small serving (210 kcal). The Big Mac and Big N’ Tasty with Cheese sandwiches contain approximately 2-fold more calories than a classic hamburger (590 versus 280 kcals). In the 1950’s, a standard serving of Coca-Cola was 6.5 fl oz, and servings marketed as “king size” were 10 to 12 fl oz¹⁶. Currently, McDonald’s beverages range from child size (12 fl oz, 110 kcal) and small (16 fl oz, 150 kcal) to large (32 fl oz, 310 kcal) and “super size” (42 fl oz, 410 kcal). Serving sizes at other major fast food restaurant chains have increased similarly.

The childhood obesity epidemic is a public health crisis.  Indeed, the disease has been associated with cardiovascular, endocrine, pulmonary, hepatic, renal, musculoskeletal, neurological, and psychosocial complications¹⁷. Immediate action is warranted to detoxify the environment. The following approaches to prevention and treatment of childhood obesity should be taken into consideration¹⁷: taxing fast food and soft drinks; subsidizing nutritious foods such as fruits and vegetables; requiring nutrition labels on fast food packaging; and prohibiting food advertisement and marketing to children.