Obesity continues to be very costly, not only in morbidity and mortality, but also in health care dollars. Colditz (1999) estimated that 300,000 adults die each year from obesity-related causes. He estimated direct costs of obesity and physical inactivity to be 9.4 percent of annual health care expenditures in the United States.

Individuals who are overweight are at increased risk for an imposing number of complications (Table 43-2). The direct link between obesity and type 2 diabetes mellitus is well known (Mokdad and associates, 2001, 2003). In one study by Hu and co-workers (2001), 16-year follow-up data were reported from the Nurses’ Health Study which began in 1974. In more than 1.3 million person-years, 3300 women developed type 2 diabetes, and the most important factor in its development was obesity.

Heart disease due to obesity (adipositas cordis) is caused by hypertension, hypervolemia, and dyslipidemia. Even before hypertension developed, Chinali and co-workers (2004) found evidence of abnormal left ventricular geometry and function in patients with the metabolic syndrome. Kenchaiah and colleagues (2002) reported a twofold risk for heart failure for women from the Framingham Heart Study who were either overweight or obese. Indeed, 14 percent of cases of heart failure were due to obesity alone. Ninomiya and co-workers (2004) found a twofold risk with the metabolic syndrome for myocardial infarction and stroke in the cohort from NHANES III.

Other common conditions that are increased in obesity are osteoarthritis and asthma.

Excessive weight is associated with increased early mortality, as shown by Peeters (2003) and Fontaine (2003) and their colleagues in follow-up studies from both the Framingham Heart Study and the NHANES III cohort. Results from a prospective study by Calle and associates (1999) are shown in Figure 43-3. The mortality risk from cardiovascular disease and cancer increased directly with increasing BMI. A subsequent study by Calle and co-workers (2003) confirmed that mortality from all causes combined, as well as from cancer, was increased in obese and overweight persons.