Although genetic factors may account for up to 50% of the variance in body fat distribution, central body fat also increases with age after young adulthood and is correlated with life style variables, e.g. smoking, and with markers of stress. These findings suggest that central body fat may be an indirect measure of cumulative burden, which, is in part, determined by environmental factors.

Epidemiological studies have used waist/hip ratio (WHR) because of the necessity to screen large numbers. WHR is usually measured over underwear in the clinic setting using inelastic tape. The technician measures the waist as the narrowest part of the torso, which is usually above the umbilicus, and the hips as the maximal part of the buttocks, taking care to measure a horizontal plane without compressing the skin. To do the latter, the technician must squat at the individual’s side to identify the maximal part of the buttocks. Because some individuals are exceptionally obese, some investigators use anatonomical anchor points (e.g. 1" above umbilicus) to identify measurement site. WHR has also been measured in the home by the participant and is highly correlated with technician measured WHR.

Body mass index is weight in kg divided by height in meters squared, although there are many other indices of body mass.

% body fat, nonessential fat mass, and fat free body mass can be calculated from skinfold thicknesses measured at seven sites. Total body fat and lean tissue mass can also be measured using bone densitometry.

Computed axial tomography (CAT) scans are used to measure subcutaneous truncal-abdominal fat. Because exposure to radiation is part of the procedure and the procedure is expensive, this technique is not used in large scale epidemiology studies. If the investigational purpose is to measure abdominal fat, then the scans are usually a single scan between 4^th and 5^th lumbar vertebrae.

Central body fat as estimated by WHR is related to risk of myocardial infarction, stroke, non-insulin dependent diabetes mellitus, hypertension, endometrial carcinoma, and polycystic ovary syndrome in epidemiological investigations. It also predicts mortality in white and African American men and in white women. It covaries with several biological risk factors for disease, e.g. with blood pressure, low HDL-C, and high insulin resistance. Several epidemiological analyses show that gender differences in CVD morbidity are eliminated by controlling for WHR, suggesting that gender differences in disease are due in part to pathogenic processes associated with central body fat.

Gothenburg, Sweden Study and the Healthy Women Study report that abdominal obesity is correlated with reports of stress and distress. WHR might be associated with weight cycling, cortisol abnormalities, and is associated with smoking. Experimental minimal data suggest a preferential deposition of fat in the abdominal area after stress exposure.

Socially subordinate female monkeys have more central body fat.