The Influence of Physical Characteristics on the Resting Energy Expenditure of Youth: A Meta-analysis

Objective: To examine the literature on resting energy expenditure (REE) of youth and determine the influence of age, sex, BMI, and body composition on REE.

Methods: A literature search was conducted using PubMed, BIOSIS Previews, NTIS, EMBASE, MEDLINE, and Pascal databases for studies with data on resting metabolic rate, REE, resting oxygen uptake (or VO ) in healthy children, youth, or adolescents (age = 1-18 years). Over 200 publications were identified; sixty-one publications met criteria and were included in the meta-analyses, resulting in 142 study population estimates (totaling 5,397 youth) of REE.

Results: Pooled mean was 1414 kcal·day with a significant and moderate-to-high between-study heterogeneity [Q(140) = 7912.42, P < 0.001; I  = 98.97%]. A significantly greater (P < 0.001) pooled mean kcal·day was estimated for studies with male participants (1519 kcal·day ) comparing to studies with female participants (1338 kcal·day ). Age, height, and body mass resulted in the highest R of 86.4 for males and 83.9% for females. Fat free mass and body mass index (BMI) did not improve total R .

Conclusions: These data suggest that using a linear equation including age, height, and body mass to estimate REE based on kcal·day is more accurate than estimates based on body mass kcal·kg ·h . Further, if kcal·kg ·h is used, including a quadratic component for the physical characteristics improves the predictive ability of the equation. Regardless of the metric, separate equations should be used for each sex.