The risk of death from all causes, including cardiovascular disease and cancer, increases with rising obesity in both men and women in all age groups, and the risk associated with a high BMI is greater for whites than for blacks (Calle et al 1999).

Obesity increases the risk of developing metabolic syndrome and coronary heart disease (Shirai 2004); type 2 diabetes (Mensah et al 2004); osteoarthritis of major load-bearing joints, such as the knee (Felson et al 1997); hypertension (high blood pressure); sleep apnea (periods of suspended breathing during sleep; Wolk et al 2003); and gall bladder disease (Petroni 2000).

The International Agency for Research on Cancer has classified obesity as a critical causal risk factor for cancers of the colon, breast (postmenopausal women), endometrium, kidney (renal cell), and esophagus (adenocarcinoma) (Calle et al 2004).

A study reported in the Journal of the American Medical Association suggests that obesity causes 111,909 deaths annually (Flegal et al 2005), while epidemiological evidence shows that a lower body weight is associated with lower mortality risk (Stevens 2000). In the well-known Framingham Heart Study, risk of death increased by 1 percent for each extra pound (0.45 kg) of weight between age 30 and 42 and increased by 2 percent between age 50 and 62 (Solomon et al 1997; Kopelman 2000).