Resting energy expenditure (REE) in an old-old population: implications for metabolic stress

The basis of nutritional therapy and thus an adequate nutrient intake is the assessment of energy need. On the other end, the assessment of individual energy requirements based on the gold standard, indirect calorimetry, is associated with feasibility difficulties in geriatric settings. To identify the most accurate predictive equations for resting energy expenditure (REE) in older subjects with overweight, 17 predictive equations were compared to indirect calorimetry measurement in a study population of 20 obese older subjects (mean BMI 33.7 ± 4.5 kg/m2; mean age 79.8 ± 8.1 years; gender 5 males and 15 females) and 20 age-matched controls with a normal body weight (mean BMI 24.9 ± 2.5 kg/m2; mean age 82.1 ± 6.6 years; gender 9 males and 11 females). The comparison led to two significant observations: the predictive equations used led to a much better estimation of the REE in the control group than in the obese older subjects. In addition, the most accurate equation for estimating the REE in the obese older subjects has been shown to be that by Lührmann et al. Further studies are needed to assess the feasibility of using this equation in a routine geriatric setting.