title: New equations for calculating the components of energy expenditure in infants.
abstract: OBJECTIVE
  To derive new equations for 24-hour energy expenditure (24-h EE; kcal/d) and resting (RMR; kcal/d) and sleeping metabolic rates (SMR; kcal/d) in young infants by using the Enhanced Metabolic Testing Activity Chamber (EMTAC).
  
  
  METHODS
  Data from 50 (25 male/25 female) healthy normally growing infants (4.9 +/- 1.6 months, 7.1 +/- 1.4 kg, 65 +/- 5 cm) who had 24-h EE, RMR, and SMR extrapolated from 4- to 6-hour metabolic measurements in the EMTAC were used to derive new equations for 24-h EE, RMR, and SMR. Equations were derived by means of multiple regression analysis (SPSS 8.0), with weight alone or with length and weight entered as independent variables. Similar data from 10 additional test infants (4 male/6 female, 5.1 +/- 0.6 months, 7.5 +/- 1.0 kg, 65 +/- 5 cm) were used to cross-validate the new equations.
  
  
  RESULTS
  Twenty-four-hour EE, RMR, and SMR were 79.6 +/- 19.2, 66.8 +/- 15.1, and 62.3 +/- 10.3 kcal/kg per day, respectively. No differences existed in RMR (kcal/kg per day) from the 10 test infants between the weight (68.6 +/- 1.9) and height-weight based equations (68.4 +/- 6.1) or that measured by the EMTAC (67.6 +/- 10.2). Weight was the major predictor of 24-h EE, RMR, and SMR. The WHO, Schofield-weight and weight-height equations underestimated (P <.05) by 19%, whereas the new equations were within 4% of RMR obtained from the EMTAC.
  
  
  CONCLUSIONS
  The new equations for assessing energy requirements in healthy infants are more accurate than those previously published that underestimated 24-h EE by 15 kcal/kg per day.
authors.affiliation: Miami Children's Hospital, Research Institute, Miami, Florida, USA.
authors.forename: Debora
authors.initials: D
authors.lastname: Duro
authors.forename: Russell
authors.initials: R
authors.lastname: Rising
authors.forename: Conrad
authors.initials: C
authors.lastname: Cole
authors.forename: Sandra
authors.initials: S
authors.lastname: Valois
authors.forename: Maribel
authors.initials: M
authors.lastname: Cedillo
authors.forename: Fima
authors.initials: F
authors.lastname: Lifshitz
mesh_terms: D002153:Calorimetry, Indirect; D004734:Energy Metabolism / Q000502:physiology*; D004780:Environment, Controlled; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008954:Models, Biological; D015999:Multivariate Analysis; D012044:Regression Analysis