‘Over-nutrition: problems of overweight and obesity’ shows that Western society’s attitude to obesity has changed, and obesity is now considered to be undesirable. A desirable body weight and body mass index (BMI) in the range of 20 to 25 kg/m2 is associated with optimal life expectancy. The health risks of obesity are wide-ranging—including a major cause of early death from cancer, coronary heart disease, and type II diabetes—and it is placing a considerable financial strain on health services. Obesity is the result of increased availability and consumption of food, coupled with decreased physical activity. The various ways in which overweight people can be helped to lose weight are considered.