BMI and waist circumference used together are highly correlated with obesity and risk of other diseases and can be used to diagnose obesity.
Classification of overweight and obesity by BMI and waist circumference | ||||
---|---|---|---|---|
Obesity class | BMI (kg/m2) | Disease risk | Disease risk with abdominal adiposity | |
>35 Women | ||||
>40 Male | ||||
Underweight | <18.5 | Not applicable | ||
Normal | 18.5–24.9 | Normal | ||
Overweight | 25.0–29.9 | Increased | High | |
Obesity | I | 30.0–34.9 | High | Very high |
II | 35.0–39.9 | Very high | Very high | |
Extreme obesity | III | 40 | Extremely high | Extremely high |
Functional evaluation
An evaluation of the individual’s functional abilities as it relates to obesity should be performed by an occupational therapist, a physical therapist, a physician, or a nurse, and ideally this should be a team effort. The functional evaluation should address activities of daily living and mobility including grooming, bathing, eating, food preparation, housework, bladder and bowel care, primary mode of mobility, and ability to transfer. An example of a functional disability related to obesity could include the inability to transfer from a wheelchair to bed or the inability to catheterize oneself. In addition , the ability to exercise should be assessed, which should encompass capability, access, and preference.
Psychosocial Evaluation
This evaluation should include the history or presence of disorders such as depression, eating disorders, and substance abuse. The social history should include employment, recreational and avocational activities, and living situation, particularly how these may contribute to the development or management of obesity. The individual’s living situation should be elucidated including the specifics of the other inhabitants and the type of dwelling such as number of floors. Details of who does grocery shopping and cooking should be determined.
Laboratory and radiologic studies
A comprehensive metabolic and lipid panel in the fasting state should be performed with particular attention to fasting blood glucose and HDL and LDL cholesterol as well as excluding any renal or hepatic abnormalities.
Determination of calorie needs
Resting energy expenditure (REE) provides important information about an individual’s daily caloric/energy needs. The REE can be determined in a variety of ways. Energy needs should be based on resting metabolic rate, ideally using the REE measured by indirect calorimetry. Although there are some handheld portable devices that are reasonably accurate and readily available, the most accurate method of determining REE is to use a metabolic cart. If REE cannot be measured by indirect calorimetry, then the REE for overweight and obese individuals can be estimated using the Mifflin-St Jeor equation using actual weight. Equations for estimating REE have been developed for a few diagnostic categories, such as those with spinal cord injuries [5]. Comparing the REE to the individual’s typical calorie/energy intake provides valuable insight into the imbalance that results in obesity.