In 1998, the National Institutes of Health established federal guidelines for the identification, evaluation, and treatment of overweight and obese adults.8 Ideal-body-weight (IBW) tables are based on actuarial studies performed by the Metropolitan Life Insurance Company.9 The amount a patient is overweight has been categorized based on body-mass index (BMI), which normalizes the weight with the patients height. Overweight is defined by having a BMI greater than 25 kg per m2, obesity is having a BMI greater than 30 kg per m2, severe obesity is having a BMI greater than 35 kg per m2, and morbid obesity is having a BMI greater than 40 kg per m2 or a BMI greater than 35 kg per m2 with concomitant obesity-related morbidity. A BMI of 40 kg per m2 roughly correlates with an actual weight exceeding ideal body weight by 100 pounds.
Federal guidelines based on studies relating BMI to morbidity and mortality have been released. Patients with a BMI between 20 and 25 kg per m2 have the lowest mortality rate.10 As BMI increases above 25 kg per m2, mean blood pressure and total blood cholesterol increase, and mean high-density lipoprotein levels decrease.11 Women with a BMI greater than 29 kg per m2 have a significantly increased incidence of myocardial infarction.12 Obese patients have an increased risk of coronary-artery disease.1314 Complications related to obstructive sleep apnea are twelvefold to thirtyfold higher in the morbidly obese than in the general population.15 The most significant observation is that morbidly obese patients who are 20 to 40 years of age may experience a twelvefold reduction in life expectancy in comparison with age-matched control subjects. These observations confirm the concept that obesity has become a national health crisis.
Once classified, it is recommended that patients who are obese or severely obese be treated medically with caloric restriction, increased physical activity, Food and Drug Administration approved weight-loss drugs, and behavioral modification. Surgery is recommended for patients who are morbidly obese or for those who are severely obese with concomitant obesity-related diseases.
Was this article helpful?