Obesity strictly refers to an excess accumulation of body fat, but body fat content is difficult to measure quickly and accurately in people. There is little doubt that overweight and obesity are common nowadays than in previous generations and that the prevalence is still rising. The prevalence of obesity is rising not just in Britain and America but throughout the industrialised world. Obesity rates were much higher in the urban areas where many people were employed in sedentary jobs and had ready access to imported western foods but less prevalent in the rural areas where the diet and lifestyle were more traditional. With increasing development and industrialisation, the rural populations were rapidly becoming as obese as their urban neighbours. In American men, rates of obesity are similar in black and white American men but more common in Hispanic men. In the industrialised countries, obesity tends to be more prevalent in the lower socio-economic groups and amongst the less well educated.