Variability in energy expenditure and its components

William T. Donahoo, James A. Levine, Edward L. Melanson

Research output: Contribution to journalReview articlepeer-review

163 Scopus citations


Purpose of review: To review factors contributing to variation in total daily energy expenditure and its primary components: (1) resting metabolic rate; (2) diet-induced thermogenesis; and (3) activity thermogenesis, including exercise energy expenditure and nonexercise activity. For each component, the expected magnitude of intra-individual variability is also considered. We also reviewed studies that quantified the variability in 24 h energy expenditure. Recent findings: In humans, the coefficient of variation in the components of total daily energy expenditure is around 5-8% for resting metabolic rate, 1-2% for exercise energy expenditure, and around 20% for diet-induced thermogenesis. The coefficient of variance for 24 h energy expenditure measured using a room calorimeter for resting metabolic rate is around 5-10%. Thus, these measures are all rather reproducible. Total daily energy expenditure varies several-fold in humans, not due to variation in resting metabolic rate, diet-induced thermogenesis, or exercise thermogenesis, but rather, due to variations in nonexercise activity. A variety of factors impact nonexercise activity, including occupation, environment, education, genetics, age, gender, and body composition, but little is known about the magnitude of effect. Summary: Resting metabolic rate, diet-induced thermogenesis, exercise energy expenditure, and 24 h energy expenditure are highly reproducible. Coefficient of variation is smallest for exercise energy expenditure, followed by resting metabolic rate, 24 h energy expenditure, and diet-induced thermogenesis. There is considerable variability in total daily energy expenditure, largely due to variations in nonexercise activity. Although the factors that impact upon nonexercise activity are understood, their contribution to variation in total daily energy expenditure is unclear.

Original languageEnglish (US)
Pages (from-to)599-605
Number of pages7
JournalCurrent Opinion in Clinical Nutrition and Metabolic Care
Issue number6
StatePublished - Nov 2004


  • Diet-induced thermogenesis
  • Exercise thermogenesis
  • Nonexercise thermogenesis
  • Resting metabolic rate
  • Total daily energy expenditure

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics


Dive into the research topics of 'Variability in energy expenditure and its components'. Together they form a unique fingerprint.

Cite this