Waist-hip circumference ratio (WHC ratio) and body mass index (BMI) were calculated from measurements of a semi-random, age-stratified sample of 4349 British men, aged 20-64 years, body weight 75.6 +/- 11.6 kg (mean +/- s.d.) and BMI 24.7 +/- 3.4 kg/m2. The mean WHC ratio was 0.89 +/- 0.06; it increased with age and overweight separately and in combination, R2 = 47 per cent. BMIs greater than or equal to 30 were found in 7 per cent of the sample and WHC ratios greater than or equal to 1 in 4 per cent of the sample. Forty-seven per cent of these latter individuals also had BMI greater than or equal to 30, but only 28 per cent of individuals with BMI greater than or equal to 30 had WHC ratios greater than or equal to 1. These indices suggest that in men abdominal obesity and whole-body obesity are usually separate conditions and that abdominal obesity is less common than obesity.