Encyclopedia of Health and Medicine

W
waist circumference The distance measured
around the waist. Doctors define the waist as the
imaginary line that circles the body between the
umbilicus (belly button) and the crest of the hip
bones. Healthy waist circumference is less than 35
inches for a woman and less than 40 inches for a
man, regardless of age. Waist circumference is an
important measure of health risk for conditions
such as OBESITY, INSULIN RESISTANCE, type 2 DIABETES,
and forms of CARDIOVASCULAR DISEASE (CVD) such as
HYPERTENSION (high BLOOD PRESSURE), HYPERLIPIDEMIA,
ATHEROSCLEROSIS, and CORONARY ARTERY DISEASE
(CAD). Excessive waist circumference also dramatically
increases risk for HEART ATTACK.
Though waist circumference alone increases
the risk for health conditions, the risk compounds
when it occurs in combination with elevated BODY
MASS INDEX (BMI). Health risk rises moderately
when BMI reaches 25 and significantly when BMI
reaches 30. In combination with waist circumference
that exceeds 35 inches for a woman or 40
inches for a man, health risk jumps to the next
level. Other risk factors for CVD, such as cigarette
smoking and physical inactivity, further increase
the likelihood for heart disease, heart attack, and
STROKE. Weight loss sufficient to decrease waist circumference
also decreases BMI, improving the
health risk.
Waist circumference that exceeds 35 inches for
women or 40 inches for men when body weight is
within the range of healthy (BMI of 18.5 to 24.9)
indicates a body fat distribution pattern of ABDOMI-
NAL ADIPOSITY, which reflects increased risk for
heart attack and CVD even when no other risk
factors for heart disease are present. Doctors recommend
modest weight loss (5 to 10 percent),
with emphasis on increased physical activity, to
reduce waist circumference.
See also HEALTH RISK FACTORS; WAIST TO HIP RATIO;
WEIGHT LOSS AND WEIGHT MANAGEMENT.
waist to hip ratio The proportion between the
distance around the waist and the distance around
the hips (WAIST CIRCUMFERENCE divided by hip circumference).
A waist to hip ratio of 0.9 in men
and 0.8 in women indicates an “apple” body
shape, which reflects an elevated body fat percentage,
heralds an increased risk for CARDIOVASCULAR
DISEASE (CVD) and HEART ATTACK in particular. The
higher the waist to hip ratio, the greater the risk.
WAIST TO HIP RATIO AND HEALTH RISK
Health Risk Men Women
healthy, no increased risk 0.89 or less 0.79 or less
moderate to significant 0.9 or greater 0.8 or less
WAIST CIRCUMFERENCE, BODY MASS INDEX (BMI), AND HEALTH RISK DUE TO WEIGHT
Health Risk Moderate Significant Severe
BMI overweight (25 to 29.9)
X
waist > 35 inches/40 inches
X
BMI overweight plus waist > 35/40 inches
X
BMI OBESITY class 1 (30 to 34.9)
X
BMI obesity class 1 plus waist > 35/40 inches
X
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