Exercise in the
Management of Obesity
STEVEN N. BLAIR
At a time when knowledge and interest in diet, nutrition, and exercise are at historically high levels, why does the prevalence of obesity continue to rise? The increase is most likely due to a combination of biological, environmental, and sociocultural factors. Biological factors have not changed over the time of the recent increase in the prevalence of obesity, but these characteristics undoubtedly predispose some individuals to become obese in the presence of an unfavorable environment (see Chapter 78). The primary environmental contributors to the increase in obesity include technological advances that have reduced the need for physical activity at home and work, and greater availability of high caloric density foods that are highly palatable and inexpensive. Possible sociocultural contributors to the rise of obesity are a prevailing mind-set that focuses on quick and simple fixes for problems, a focus on unrealistic ideals of thinness, and overreliance on diet as an approach to weight loss and management.
The primary intervention used for weight reduction continues to be based on a reduction of energy intake (i.e., diet), but increased energy expenditure (i.e., physical activity) is receiving more attention. There also are a variety of pharmacological and surgical options now available for the treatment of obesity. It is imperative that these medical treatments be viewed as adjuncts to increased physical activity and the development of healthy dietary habits if long-term success is to be achieved.
Physical activity appears to delay or prevent weight gain often associated with aging (see Chapter 81). From 1970 to 1994, we followed 4,599 men and 724 women who received