The purpose of the study was to provide information on dietary intake in the InCHIANTI study population, a representative sample (n = 1453) of persons living in two towns of Tuscany (Italy), including a large number of old and very old individuals (79.5% >65 y old). We also investigated whether difficulties in nutrition-related activities were associated with inadequate intake of selected nutrients. The percentage of persons with an inadequate intake of nutrients according to Italian Recommended Nutrients Levels (LARN) was higher in the older age groups. Older persons tended to adapt their diets in response to individual functional difficulties, often leading to monotonous food consumption and, as a consequence, to inadequate nutrient intakes. Multiple logistic models were used to evaluate whether inadequate intake of selected nutrients could be predicted by nutrition-related difficulties. Reporting difficulties in three or more nutrition-related activities (chewing, self-feeding, shopping for basic necessities, carrying a shopping bag, cooking a warm meal, using fingers to grasp or handle) significantly increased the risk of inadequate intake of energy [odds ratio (OR) = 3.8, 95% CI = 1.9-7.8) and vitamin C (OR = 2.2, 95% CI = 1.2-4.2, after adjustment for energy intake). More attention to functional problems in the elderly population and the provision of formal or informal help to those who have difficulty in purchasing, processing and eating food may reduce, at least in part, the percentage of older persons with poor nutrition.