Abstract

ntroduction: The resting metabolic rate (RMR) can be measured by indirect calorimetry (RMR IC) or estimated by predictive equations, which can overestimate or underestimate energy requirements. Objective: To compare RMRs measured by indirect calorimetry and estimated by predictive equations in young adult and elderly women with normal body mass index (BMI). Subjects and methods: Analytical cross-sectional study. RMR IC was measured and esti- mated by Harris-Benedict (1919), FAO/WHO/UNU (1985), FAO/ WHO/UNU (2004), and Miffl in-St Jeor equations in 36 young adult women aged 20 to 24 years (BMI 20.7–1.6) and 29 elderly women aged 60 to 76 years (BMI 25.5–1.6). Measures of central tendency, dispersion, and position were calculated for quantitative variables. The Kruskal-Wallis test was used to compare RMR bet- ween the different formulae and the Mann-Whitney test was used to compare RMR IC between groups after verifying normality by the Shapiro Wilks test. The statistical significance level was = 0.05. Results: The Harris-Benedict, FAO/WHO/UNU (2004), FAO/OMS/ UNU (1985), and Mifflin-St Jeor equations showed a statistically significant overestimation (p<0.0001) of 290.5, 196.8, 200.1, and 188.0 kcal/d and 220.0, 211.9, 235.8, and 79.4 kcal/d in young adult and elderly women, respectively.The RMR IC between young adult women (1050.0 kcal/d) and elderly women (985,0 kcal/d) exhibited a signifi cant statistical difference (p=0.008). A higher overestimation was found by the Harris-Benedict test and the FAO/ WHO/UNU (1985) equation in young adult and elderly women, respectively. Conclusions: Predictive equations overestimated RMR in young adult and elderly women. Thus, its routine use could lead to malnutrition due to excess intake.