An increasingly sedentary lifestyle is making Americans, largely white, obese. The US National Health and Nutrition Examination Survey, conducted between 1988-91, reveals that 33.4 per cent of Americans 20 years of age or older were estimated to be adipose -- an increase of 8 per cent over the figures from the earlier survey from 1976-80 (The Journal of the American Medical Association, Vol 273, No 3).

Independent data from the US National Health Interview Survey indicated that the percentage of adults who exercised or played sports regularly dropped steeply between 1985 and 1990.