Overeating
Overeating
Overeating is a relative term, defined as food consumption that exceeds energy expenditure. Chronic overeating typically results in obesity and is not uncommon. In fact, obesity is at epidemic proportions for all age groups, and is seen as a growing health threat not just in Western societies but also in much of the world. Risk for obesity increased markedly during the 1980s, an increase that is attributable to a complex combination of environmental, sociocultural, genetic, and behavioral factors.
Overeating can be either active or passive. Active overeating is largely the consequence of a convergence of sociocultural factors that most notably include aggressive mass marketing of energy- or caloriedense foods (foods high in fat, refined carbohydrates, and sugar) and disproportionately large portions of food relative to individuals’ actual caloric needs. Not coincidentally, such foods are easily accessible, widely available, relatively affordable, and highly palatable. Unsurprisingly, society has fallen prey to marketing influences, and consumption of such foods is on the rise. It is noteworthy that, as of 2006, the highest rates of obesity and obesity-related disorders in the United States are found in lower-income groups for whom the marketing of energy-dense, low-cost foods is most pervasive.
Active overeating is also part of the symptom complex of conditions such as bulimia nervosa and binge eating disorder. With bulimia, individuals experience a sense of being unable to control what and how much they eat, and they engage in recurrent episodes during which they very rapidly consume an abnormally large quantity of food. This symptom is also a defining characteristic of binge eating disorder. A key distinction between bulimia and binge eating disorder is that with bulimia, individuals engage in dangerous methods of weight control (e.g., purging, fasting, and vomiting), whereas with binge eating disorder, individuals do not engage in such weight control efforts and, in fact, may be obese. Active overeating may also result from hypothalamic dysfunction, either due to genetic defects (e.g., Prader-Willi syndrome), physical injury, or pharmacological agents.
Although active overeating accounts for a substantial proportion of the high rates of obesity, passive overeating may best explain prevalence rates. There are several aspects to consider in passive overeating. First, as is perhaps obvious, individuals with an energy-dense diet who consume food equal in quantity to individuals with a lower-energy diet have an overall greater energy intake. Second, lower-energy diets are most satiating, whereas energy-dense diets are least satiating: Consumption of a greater quantity of energy-dense foods is required to achieve equal levels of satiety. Thus, passive overeating is the unintentional, but inevitable, consequence of a diet that is energy-dense. Given that it is also a prime factor in the energy balance equation, physical inactivity compounds the issue. Technological advances promote an increasingly sedentary lifestyle that, in combination with active or passive overeating, further subverts the energy equation, resulting in ever-rising obesity rates.
Although research on pharmacological interventions to treat obesity is ongoing, lifestyle changes are likely to remain central features of any intervention. It may, however, require major macrosystemic social change to effect significant improvement in our nutrition and physical activity.
SEE ALSO Nutrition; Obese Externality; Obesity; Schachter, Stanley
BIBLIOGRAPHY
American Psychiatric Association. 2000. Diagnostic and Statistical Manual of Mental Disorders (DSM -IV-TR). 4th ed., text rev. Washington, DC: Author.
Hill, James O., Holly R. Wyatt, George W. Reed, and John C. Peters. 2003. Obesity and the Environment: Where Do We Go from Here? Science 299 (5608): 853–855.
Joan K. Orrell-Valente