Social and economic effects of body weight in the United States.

Given that overweight is clearly associated with increased risk of many major chronic diseases, the United States could have saved approximately $45.8 billion or 6.8% of health care expenditures in 1990 alone if obesity were prevented. The question then arises, economically and socially, what is a healthy body weight? Using a prevalence-based approach to cost of illness, we estimated the economic costs (1993 dollars) associated with illness at different strata of body mass indexes (BMIs, in kg/m2) and varying increments of weight gain to address the questions: At what body weight do we initiate preventive services? What are the direct costs associated with weight gain? Second, using the 1988 National Health Interview Survey (NHIS), we evaluated the marginal increase in certain social indexes reflective of functional impairment and morbidity (ie, restricted-activity days, bed days, and work-loss days) as well as physician visits associated with different strata of BMI. With respect to economic and social indexes, a healthy body weight appears to be a BMI < 25, and weight gain should be kept to < 5 kg throughout a lifetime.