Treatment of the overweight or obese patient is a two-step process: assessment and treatment management. Assessment requires determination of the degree of overweight and overall risk status. Management includes both reducing excess body weight and instituting other measures to control accompanying risk factors.
Assessment: When assessing a patient for risk status and as a candidate for weight loss therapy, consider the patient’s BMI, waist circumference, and overall risk status. Consideration also needs to be given to the patient’s motivation to lose weight.
Body Mass Index. The BMI, which describes relative weight for height, is significantly correlated with total body fat content. The BMI should be used to assess overweight and obesity and to monitor changes in body weight. In addition, measurements of body weight alone can be used to determine efficacy of weight loss therapy. BMI is calculated as weight (kg)/height squared (m2). To estimate BMI using pounds and inches, use: [weight (pounds)/height (inches)2] x 703. Weight classifications by BMI, selected for use in this report, are shown in Table given below.
Waist Circumference. The presence of excess fat in the abdomen out of proportion to total body fat is an independent predictor of risk factors and morbidity. Waist circumference is positively correlated with abdominal fat content. It provides a clinically acceptable measurement for assessing a patient’s abdominal fat content before and during weight loss treatment. The sex-specific cutoffs noted on the next page can be used to identify increased relative risk for the development of obesity-associated risk factors in most adults with a BMI of 25 to 34.9 kg/m2:
These waist circumference cutpoints lose their incremental predictive power in patients with a BMI ³ 35 kg/m2 because these patients will exceed the cutpoints noted above. The disease risk of increased abdominal fat to the disease risk of BMI. These categories denote relative risk, not absolute risk; that is, relative to risk at normal weight. They should not be equated with absolute risk, which is determined by a summation of risk factors. They relate to the need to institute weight loss therapy and do not directly define the required intensity of modification of risk factors associated with obesity.
(Source: Overweight and Obesity in Adults)