Oral supplements differing in fat and carbohydrate content: effect on the appetite and food intake of undernourished elderly patients

Background & aims: Since fat, relative to other macronutrients, has low satiety and high energy density, it may have therapeutic application for supplementing energy intake. This study compared the effect of isoenergetic (1050 kJ) high fat or high carbohydrate oral supplements, given at breakfast, on the short-term appetite and energy intake in undernourished elderly subjects. Methods: Sixteen hospitalised, undernourished (body mass index: 20±3 kg/m2), elderly (77±8 yr) people were randomly allocated to a control or 1 of 2 supplement groups [fat: carbohydrate: protein (% energy) was 70:25:5 or 25:70:5]. In each group, energy intake (24-h food consumption) and appetite (visual analogue scales) were assessed over 3 consecutive days. Results: Mean energy intake significantly (P=0.0035) increased following supplementation: high fat 6973 kJ/d, high carbohydrate 6906 kJ/d vs. control 6079 kJ/d but mean voluntary 24-h energy intake remained unaffected. Compared to controls, supplemented subjects experienced reduced hunger (P=0.07) between breakfast and lunch, but showed no difference over the whole day (P=0.55). Conclusions: Under these study conditions a 1050 kJ oral supplement, irrespective of macronutrient composition, does not cause voluntary short-term energy intake compensation in undernourished elderly people.