Background: It was hypothesized that energy intake in hospitalized elderly patients could be improved by increasing the density of energy of the food and that the volume of food actually consumed, even with a higher energy content than the normal, would not change with servings of high energy-dense hospital food.
Methods: Thirty-six elderly patients (52 to 96 years) of both sexes, long-term treated at two comparable wards, participated in this study. The patients were given 6 weeks of regular hospital food (RHF, 1670 kcal/d, 7.0 MJ) and 6 weeks of high-energy food (HE, 2520 kcal/d, 10.5 MJ). The volume of food was kept constant. A crossover study design was used. Food intake, energy intake, body weight, and modified functional condition (Norton scale) were measured.
Results: Regardless of type of food (RHF or HE) and time of day (lunch or dinner), he food portion size (volume of food) intake was the same, approximately 80% of the portions consumed. HE led to a 40% increase in energy intake (from 25 +/- 1 during RHF to 35 +/- 2 kcal/kg/d, p < .0001), which resulted in a 3.4% increase in body weight (p < .001) after 3 weeks of HE. Only minimal changes in functional condition were found. The cost of HE was substantially lower (-85%) than any other mean available for improvement of energy intake.
Conclusions: A significant increase in energy intake can be achieved by higher energy density in regular hospital food and that HE does not cause a decrease in the volume of the food consumed. These findings suggest that it is the volume of food rather than the energy that limits voluntary energy intake of hospital food in elderly hospitalized patients.