The World Health Organization estimates that 25 percent of common cancers can be prevented through regular physical activity and weight control. Common cancers linked to overweight/obesity and a sedentary lifestyle include breast, colon, endometrium, pancreas, renal, esophageal, and several others. There are several plausible mechanisms linking lack of physical activity and increased adiposity to cancer risk, supported by results from animal experiments and human intervention studies.

The American Institute for Cancer Research (AICR) sponsored its second annual conference on nutrition and cancer. The theme was "Exercise, Calories, Fat, and Cancer" and the conference was held September 4-5, 1991 at the Ritz Carlton Hotel in Pentagon City, Virginia. This proceedings volume contains chapters from the platform presentations and abstracts from each poster presentation. Relationships among physical activity, calorie consumption, energy expenditure, dietary fat, and cancer are described in the context of epidemiologic, animal, and in vitro studies. Dietary recommendations to lower cancer risk are based on expanding evidence relating nutrition and cancer. Identification of the precise dietary contribution to disease is complicated by the concurrent genetic and environmental contributions, in addition to the inherent difficulties in gathering and interpreting epidemiologic data. Individual variations in cancer risk are the result of differences in genetic and environmental factors including sources and amounts of calories consumed, metabolism, and energy expenditure. Human and animal studies describing independent and combined influences of exercise, calorie restriction, and dietary fat on carcinogenesis are reported in this volume.

Avoiding overweight and obesity is the best-established diet-related risk factor for cancer. The proportion of people who are overweight/obese is increasing, and the amount of physical activity is decreasing in most populations, including urban populations in many developing countries. The increasing prevalence of overweight/obesity is presumably due to the increasing availability of highly palatable, high-energy foods, and an increasing sedentary lifestyle due to mechanisation of both workplace and leisure activities. Overweight/obesity and reduced physical activity increases the risk of cancers in various organs. Maintaining a healthy body weight and regular physical activity is the second most important way to prevent cancer, after tobacco control. The suggestions of possible public health actions to tackle these risk factors include the promotion of balanced diets, which are not excessive in energy, and broad education and planning to enable and encourage physical activity during work and leisure. Recommendations and a full discussion of these topics are included in the sixth volume in this series of Handbooks.

Food or calorie restriction has been shown in many short-lived animals and the rhesus monkey to prolong life-span. Life-long nutrition studies are not possible in humans because of their long survival. Studies over two to six years in healthy adult humans have, however, shown that a 20% reduction in food or calorie intake slows many indices of normal and disease-related aging. Thus, it is widely believed that long-term reduction in calorie or food intake will delay the onset of age-related diseases such as heart disease, diabetes and cancer, and so prolong life. Over the last 20 or more years there has been a progressive rise in food intake in many countries of the world, accompanied by a rising incidence of obesity. Thus our increasing food and calorie intake has been linked to the rising incidence of cardiovascular disease and diabetes in early adult life. It is accepted that overeating, accompanied by reduced physical exercise, will lead to more age-related diseases and shortening of life-span. The answer is to reduce our calorie intake, improve our diet, and exercise more. But calorie restriction is extremely difficult to maintain for long periods. How then can we solve this problem? Edited by a team of highly distinguished academics, this book provides the latest information on the beneficial effects of calorie restriction on health and life-span. This book brings us closer to an understanding at the molecular, cellular and whole organism level of the way forward.

Diet and Health examines the many complex issues concerning diet and its role in increasing or decreasing the risk of chronic disease. It proposes dietary recommendations for reducing the risk of the major diseases and causes of death today: atherosclerotic cardiovascular diseases (including heart attack and stroke), cancer, high blood pressure, obesity, osteoporosis, diabetes mellitus, liver disease, and dental caries.