According to data from NHNESIII (the third National Health and Nutritional Examination Survey), of 16,884 adult subjects, 63% men and 55% women were classified as over weight or obese (BMI over 25). For all health outcomes studied (type 2 diabetes, gallbladder disease, coronary heart disease, hypercholesterolemia, hypertension and osteoarthritis), there was an increase in prevalence ratio with increasing severity of over weight and obesity, with the exception of coronary heart disease in men and hypercholesterolemia in men and women. In individuals aged less than 55 with BMIs greater than or equal to 40, prevalence ratios were highest for type 2 diabetes (18.1 for men, 12.9 for women), and gallbladder disease (21.1 men, 5.2 women). Across racial and ethnic subgroups, prevalence of having two or more health conditions increased concurrently with weight.
Source: Must, et al., JAMA, 282: 1523-9, 1999.