Body Mass Index (BMI)
A mathematical measure of total body size and its correlation to health risk. BMI values derive from height (without shoes) and weight (without clothes) measures, with mathematical calculations that convert those measures to a value that reflects overall body size. BMI represents the mass of the body in kilograms per meter squared (kg/m2) though the common presentation of BMI is simply the numeric value. A low or a high BMI corresponds with increased risk for numerous health conditions. A BMI of 25 or greater is overweight; a BMI of 30 or greater is OBESITY. BMI values apply to men or women who have the same measurements. For example, a man who is 5 feet 8 inches tall and weighs 175 pounds has the same BMI as a woman who is 5 feet 8 inches tall and weighs 175 pounds.
For most people a high BMI indicates increased body fat. The higher the BMI is above the “healthy” range, the greater the health risk for HYPERTENSION (high BLOOD PRESSURE), type 2 DIABETES, and forms of CARDIOVASCULAR DISEASE (CVD) such as HYPERLIPIDEMIA, ATHEROSCLEROSIS and CORONARY ARTERY DISEASE (CAD). Risk for these conditions further increases when WAIST CIRCUMFERENCE also is greater than 40 inches for men and 35 inches for women, though waist circumference is itself an independent risk factor for the same health conditions. Losing weight drops BMI and reduces health risk.
BMI values may not be accurate in children, the elderly, and performance athletes because body mass may not correctly reflect body composition. The elderly may have more body fat than BMI indicates, with a correspondingly higher health risk. Performance athletes (amateur or professional) typically have higher LEAN MUSCLE MASS (large skeletal muscles) and lower body fat percentages than less physically active people of the same weight; the increased MUSCLE mass raises the BMI even though body fat is lower.
See also ABDOMINAL ADIPOSITY; CHILDHOOD OBESITY; DIET AND HEALTH; EXERCISE AND HEALTH; LIFESTYLE AND HEALTH; NUTRITIONAL ASSESSMENT; NUTRITIONAL NEEDS; OBESITY AND HEALTH; WEIGHT LOSS AND WEIGHT MANAGEMENT.