Energy requirements in hospitalized elderly people.

Objectives: To estimate energy intake and energy expenditure (EE) in elderly hospitalized patients recovering from an acute illness.

Design: Cross-sectional evaluation of the disparity between energy intake and expenditure.

Participants: Ninety geriatric patients (mean age+/-standard deviation 79.7+/-7.5) admitted to acute care or rehabilitation units.

Measurements: Patients' energy intake and resting EE (REE) were measured over a 3-day period. Blood samples were taken to determine C-reactive protein (CRP), creatinine, and albumin concentrations and to check renal function.

Results: Energy intake was higher than REE by a factor of 1.29, but it was lower than the energy requirement. Energy intake, adjusted for differences in body weight, was independent of sex, highest in those who were malnourished (defined as a body mass index (BMI) <21), and lowest in patients who scored poorly on the Mini-Mental State Examination. Energy intake and REE were independent of plasma CRP, creatinine, and albumin concentrations, as well as the initial diagnosis. REE was similar in men and women, at 18.8 kcal/kg per day. REE was 21.4 kcal/kg per day in patients with a BMI of 21 or less and 18.4 kcal/kg per day in those with a BMI greater than 21 kg/m2. The Harris-Benedict equation accurately predicted mean REE.

Conclusion: The mean REE of the geriatric patients studied was 18.8 kcal/kg per day, whereas energy intake was just sufficient to cover minimal requirements. Thus, hospitalized elderly patients are likely to benefit from higher calorie intake.