Validation of predictive equations to estimate resting metabolic rate of females and males across different activity levels

Abstract

ObjectivesUsing equations to predict resting metabolic rate (RMR) has yielded different degrees of validity, particularly when sex and different physical activity levels were considered. Therefore, the purpose of the present study was to determine the validity of several different predictive equations to estimate RMR in female and male adults with varying physical activity levels.MethodWe measured the RMR of 50 adults (26 females and 24 males) evenly distributed through activity levels varying from sedentary to ultra‐endurance. Body composition was measured by dual X–ray absorptiometry and physical activity was monitored by accelerometry. Ten equations to predict RMR were applied (using Body Mass [BM]: Harris & Benedict, 1919; Mifflin et al., 1990 [MifflinBM]; Pontzer et al., 2021 [PontzerBM]; Schofield, 1985; FAO/WHO/UNU, 2004; and using Fat‐Free Mass (FFM): Cunningham, 1991; Johnstone et al., 2006; Mifflin et al., 1990 [MifflinFFM]; Nelson et al. 1992; Pontzer et al., 2021 [PontzerFFM]). The accuracy of these equations was analyzed, and the effect of sex and physical activity was evaluated using different accuracy metrics.ResultsEquations using BM were less accurate for females, and their accuracy was influenced by physical activity and body composition. FFM equations were slightly less accurate for males but there was no obvious effect of physical activity or other sample parameters. PontzerFFM provides higher accuracy than other models independent of the magnitude of RMR, sex, activity levels, and sample characteristics.ConclusionEquations using FFM were more accurate than BM equations in our sample. Future studies are needed to test the accuracy of RMR prediction equations in diverse samples.

Validity of predictive equations for total energy expenditure against doubly labeled water

“…The statistical analysis was similar to those previously described by Prado-Nóvoa et al 22 . T-test analyses were used to compare sample descriptive characteristics by sex.…”

“…Fifty-six healthy individuals (20–58 years; 27 females) with a wide range of habitual physical activity levels were recruited as part of a larger study. The participants were uniformly distributed across levels of self-reported physical activity, walking and/or running from 0 km per week to more than 120 km per week 22 .…”

“…The volunteers included in the study were properly informed and verbal and written consent were obtained. Detailed experimental procedures have been described previously 22 .…”

“…RMR was measured with indirect calorimetry (Parvo Medics, TrueOne 2400 Metabolic Measurement System, OUSW 4.3.4; Murray, Utah, USA) using a ventilated canopy in a rested state (after a minimum of 12 h with no exercise, and after fasting for 12 h) as described previously 22 , 23 . The last 30 min of a 45-min measurement period were used for analysis.…”

“…Participants wore the accelerometer around their waist continuously for 14 days, removing it only for swimming, showering/bathing, or sleeping. Data collection was described in Prado-Nóvoa et al 22 . Only individuals with at least 4 days each week for at least 10 h a day or more wear time were included for analysis.…”