Given the impact that good nutrition and keeping fit have on health and well-being later in life, the WHO, in collaboration with the Tufts University USDA Human Nutrition Research Center on Ageing, organized a consultation to review the scientific evidence linking diet and other factors - especially exercise - affecting nutritional status, disease prevention and health promotion for older persons. The consultation focused primarily on practical issues, including the establishment of explicit recommendations to improve the health and nutritional status of older persons in a wide variety of socioeconomic and cultural settings. During the production of a comprehensive report, representing the outcome of both the preparatory work and of the consultation itself, it was recognized that new information emerging in several key areas should also be included. The combined results presented here are intended as an authoritative source of information for nutritionists, general practitioners, gerontologists, medical faculties, nurses, care providers, schools of public health and social workers. The specific recommendations concerning nutrient intakes, food-based dietary guidelines, and exercise and physical activity should also interest a larger audience, including the general reader. The main body of the study discusses the epidemiological and social aspects of ageing, health and functional changes experienced with ageing, the impact of physical activity, assessment of the nutritional status of older persons, and nutritional guidelines for health ageing. Additional material covers food-based dietary guidelines for older adults - with particular emphasis on healthy ageing and prevention of chronic noncommunicable diseases - and guidelines for promoting physical activity among older persons. Nearly 400 references to scientific literature are included.