The age of the population continues to increase. At the turn of the century, 4% (about 3.1 million people) were 65 years of age or older. Today the percentage has increased to 12%, or 27.4 million people, and the prediction for the 21st century may increase to 17 to 20%. It should be noted that the number of individuals 85 years of age and older, as well as those over the age of 100, is increasing rapidly. The nutritional problems of the elderly are related to physiological decline, to low economic status and limited food consumption, and to a multitude of disease processes and the therapeutic regimens prescribed to cure or treat those illnesses. Examined as a group, the elderly at first appear to be less uniform in their health status than younger members of the population. However, only 10% of the elderly population contributes to the disproportionate (30%) expenditure of health care services. A majority of the elderly are normal, healthy individuals. Yet, with each decade of life the percentage of the elderly population needing additional care increases. The national nutritional surveys (National Food Consumption Survey and the National Health and Nutrition Examination Surveys, I and II) used entirely different methodologies, but reported very similar findings. The mean intake of this population was actually quite good, revealing low intakes of calcium and iron in the elderly female population. However, the standard deviation of the intake data strongly suggests a major portion of the population is at nutritional risk. For more than 30% of the population, nutrient intakes below two thirds of the recommended dietary allowances (RDA) occurred for calories, calcium, and vitamin A, while for more than 20% of the population, iron and vitamin C were at risk. Although the data evaluating the effects of age on the nutritional requirements of the elderly are limited, careful interpretation of the existing assessment and intervention efforts can provide some basic guidelines. Generalities about calorie intake must be avoided, and emphasis must be placed on calorie needs. Enhanced activity should be encouraged. Protein intake for the majority of elderly exceeds the RDA, but with increased age a greater amount of high quality protein is needed to maintain nitrogen balance. The group at greatest risk is the poor elderly who may not be able to afford enough high quality protein. Increased consumption of complex carbohydrates serves several functions including decreased caloric density and enhanced nutrient intake. Decreasing total dietary fat decreases caloric intake and indirectly decreases dietary cholesterol.(ABSTRACT TRUNCATED AT 400 WORDS)