title: An objective estimate of energy intake during weight gain using the intake-balance method.
abstract: BACKGROUND
  Estimates of energy intake (EI) in humans have limited validity.
  
  
  OBJECTIVE
  The objective was to test the accuracy and precision of the intake-balance method to estimate EI during weight gain induced by overfeeding.
  
  
  METHODS
  In 2 studies of controlled overfeeding (1 inpatient study and 1 outpatient study), baseline energy requirements were determined by a doubly labeled water study and caloric titration to weight maintenance. Overfeeding was prescribed as 140% of baseline energy requirements for 56 d. Changes in weight, fat mass (FM), and fat-free mass (FFM) were used to estimate change in energy stores (ΔES). Overfeeding EI was estimated as the sum of baseline energy requirements, thermic effect of food, and ΔES. The estimated overfeeding EI was then compared with the actual EI consumed in the metabolic chamber during the last week of overfeeding.
  
  
  RESULTS
  In inpatient individuals, calculated EI during overfeeding determined from ΔES in FM and FFM was (mean ± SD) 3461 ± 848 kcal/d, which was not significantly (-29 ± 273 kcal/d or 0.8%; limits of agreement: -564, 505 kcal/d; P = 0.78) different from the actual EI provided (3490 ± 729 kcal/d). Estimated EI determined from ΔES in weight closely estimated actual intake (-7 ± 193 kcal/d or 0.2%; limits of agreement: -386, 370 kcal/d; P = 0.9). In free-living individuals, estimated EI during overfeeding determined from ΔES in FM and FFM was 4123 ± 500 kcal/d and underestimated actual EI (4286 ± 488 kcal/d; -162 ± 301 kcal or 3.8%; limits of agreement: -751, 427 kcal/d; P = 0.003). Estimated EI determined from ΔES in weight also underestimated actual intake (-159 ± 270 kcal/d or 3.7%; limits of agreement: -688, 370 kcal/d; P = 0.001).
  
  
  CONCLUSIONS
  The intake-balance method can be used to estimate EI during a period of weight gain as a result of 40% overfeeding in individuals who are inpatients or free-living with only a slight underestimate of actual EI by 0.2-3.8%.
authors: From the Pennington Biomedical Research Center, Baton Rouge, LA.
authors: L Anne
authors: LA
authors: Gilmore
authors: From the Pennington Biomedical Research Center, Baton Rouge, LA.
authors: Eric
authors: E
authors: Ravussin
authors: From the Pennington Biomedical Research Center, Baton Rouge, LA.
authors: George A
authors: GA
authors: Bray
authors: From the Pennington Biomedical Research Center, Baton Rouge, LA.
authors: Hongmei
authors: H
authors: Han
authors: From the Pennington Biomedical Research Center, Baton Rouge, LA.
authors: Leanne M
authors: LM
authors: Redman
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D006963:Hyperphagia / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008954:Models, Biological; D015596:Nutrition Assessment; D009765:Obesity / Q000209:etiology / Q000378:metabolism; D050177:Overweight / Q000209:etiology / Q000378:metabolism; D015203:Reproducibility of Results; D022722:Thermogenesis; D015430:Weight Gain; D055815:Young Adult