Obesity is a dimension of body image based on a society’s consideration of acceptable body size and, as such, is the focus of anthropological, sociological, and psychological study (de Garine and Pollock 1995). However, most of the research on obesity in Western societies has focused on medical issues ranging from genetic etiology to therapeutic interventions. Overfatness or obesity is a major health problem in countries that are affluent and is increasing in prevalence among the socioeconomic elite of those that are modernizing. An estimated 90 million Americans – one-third of the population – are substantially above their range of desirable body weight; in some other populations more than half of their members fit into this category.

Of course, some fat or adipose tissue is essential for life and serves a number of functions. It provides metabolic fuel; thermal insulation; a reservoir for vitamins, hormones, and other chemicals; and protection for the viscera and dermal constituents, such as blood vessels, nerves, and glands (Beller 1977). However, an excessive accumulation of fat is associated with an increased risk for diabetes, hypertension, cardiovascular and musculoskeletal problems, and in general, a reduced life expectancy. Moreover, in many societies, fatness elicits a psychosocial stigma.

Definitions and Diagnosis

Body weight is the most widely used anthropometric indicator of nutritional reserves, and weight relative to height is an acceptable measure of body size for growth monitoring and for most epidemiological surveys. Overweight and obesity, though often used synonymously, are not the same. S. Abraham and co-workers (1983) clearly made the distinction in analyzing data from the first U.S. National Health and Nutrition Examination (NHANES) survey. Overweight was defined as an excess in body weight relative to a range of weights for height. In this report, individuals over the 85th percentile of weight for height standards are considered overweight. Obesity was defined as an excess of body fat based on the sum of the triceps (upper arm) skinfold and subscapular (back) skinfold. Skinfold measurements using calipers that pinch a fold of skin and subcutaneous fat at specific sites (for example, waist, abdomen, thighs, upper arm, and back) are used in equations to estimate body fat stores and are compared with reference percentile tables (Himes 1991).