AGE-RELATED IMPAIRMENTS IN THE REGULATION OF FOOD-INTAKE

Low food intake in elderly individuals increases the risk for many nut rition-related acute or chronic illnesses. It is not known whether agi ng is associated with changes in hunger and satiety, or whether elderl y individuals can regulate energy intake in response to manipulations of the energy or nutrient content of foods. Therefore, this study inve stigated short-term energy regulation in healthy elderly (n = 16; aged 60-84 y) and young (n = 16; aged 18-35 y) men. Participants were give n yogurt preloads that varied in energy and macronutrient content (low -fat, low energy, 962 kJ; high-fat, high-energy, 2134 kJ; high-carbohy drate, high-energy 2134 kJ), or no yogurt, followed by a self-selected lunch (presented 30 min after subjects began to consume the yogurt). Energy intake, the percentage of macronutrients consumed in the meals, and subjective sensations of hunger and satiety were analyzed. The el derly men consumed significantly less energy than the young men in the baseline (no yogurt) condition. Lower intake was concordant with subj ective sensations of satiety; visual analog data indicated that the ol der men were less hungry and more full at the start of lunch. Compensa tion for energy in the preloads was less precise in the elderly than i n the young men, in that elderly men consistently overate at the self- selected lunch. Young men consumed +/- 10% total energy (lunch + yoghu rt) in the yogurt preload conditions compared with their baseline inta ke; elderly men overate between 10% and 30% in relation to their basel ine intake. The proportions of macronutrients consumed in the test mea ls did not differ significantly across preload conditions or between t he young and elderly participants. There were also no differences betw een the satiating effects of fat and carbohydrate. These results indic ate that energy regulation is impaired in elderly individuals. Consumi ng an energy-dense nutritional supplement before a meal may be an appr opriate strategy to increase energy and nutrient intakes in elderly pe ople.