title: Published predictive equations overestimate measured resting metabolic rate in young, healthy females.
abstract: OBJECTIVE
  To compare resting metabolic rate (RMR) measured by indirect calorimetry versus RMR predicted by several published formulas in a sample of healthy young women.
  
  
  METHODS
  RMR was measured using indirect calorimetry and predicted using 6 commonly used equations (Nelson, 1992; Mifflin, 1990; Owen, 1986; Schofield(Weight), 1985; Schofield(Weight and Height), 1985; Harris-Benedict, 1919) in 47 reportedly healthy young females (age = 22.8 ± 2.9 years; body mass index = 21.8 ± 2.1 kg/m(2)). Comparisons between measured versus predicted RMR were conducted using paired t tests, and agreement using Pearson's correlation coefficient, analysis of variance, and the method of Bland-Altman.
  
  
  RESULTS
  All 6 equations overestimated measured RMR by 140-738 kcal/d (all p < 0.001). The proportion of subjects for whom measured versus predicted RMR differed by ±10% ranged from 74% (Nelson) to 100% (Harris-Benedict). The adjusted coefficients of determination (R(2)) between measured and predicted RMR ranged from 0.13 to 0.19 (all p < 0.05). Bland-Altman analysis R(2) values ranged from 0.03 (p = 0.233; Harris-Benedict) to 0.72 (p = 0.000; Owen). Given its continued popularity, we modified the Harris-Benedict equation (RMR(modified Harris-Benedict) (kcal/d) = 738 / (RMR(Harris-Benedict) - 738)). Doing so reduced the mean difference between measured and predicted RMR from +738 kcal/d to -0.53 kcal/d (p = 0.984).
  
  
  CONCLUSIONS
  No equation performed well, and none should be used interchangeably with measured RMR. We recommend that a new equation be validated for, and prospectively tested in, young women. In the interim, RMR should be measured in this population or predicted using the modified Harris-Benedict equation that we developed.
authors.affiliation: Department of Family Relations and Applied Nutrition, Macdonald Stewart Hall, Room 326, University of Guelph, 50 Stone Road East, Guelph ON N1G 2W1, Canada.
authors.forename: Amanda C
authors.initials: AC
authors.lastname: Li
authors.forename: Carolyn M
authors.initials: CM
authors.lastname: Tereszkowski
authors.forename: A Michelle
authors.initials: AM
authors.lastname: Edwards
authors.forename: Janis A Randall
authors.initials: JA
authors.lastname: Simpson
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Buchholz
mesh_terms: D000328:Adult; D000465:Algorithms; D001481:Basal Metabolism; D002153:Calorimetry, Indirect / Q000379:methods; D005260:Female; D006801:Humans; D012016:Reference Values; D015203:Reproducibility of Results; D055815:Young Adult