title: Extent and determinants of thermogenic responses to 24 hours of fasting, energy balance, and five different overfeeding diets in humans.
abstract: BACKGROUND
  Individual variation in the ability to convert excess calories to heat and the effects of dietary macronutrient composition are unclear.
  
  
  OBJECTIVE
  Stability and determinants of the energy expenditure (EE) response to overconsumption were assessed.
  
  
  METHODS
  Twenty subjects (75% male) with normal glucose regulation were evaluated during 24 hours each of energy balance, fasting, and 5 different diets with 200% energy requirements in a clinical research unit.
  
  
  METHODS
  Five 1-day overfeeding diets were given in random order: high carbohydrate (75%) and low protein (3%); high carbohydrate and normal protein (20%); high fat (46%) and low protein; high fat (60%) and normal protein; and balanced (50% carbohydrates, 20% protein).
  
  
  METHODS
  The 24-hour EE, sleeping EE, and thermic effect of food (TEF) during each diet were measured with a metabolic chamber. Appetitive hormones were measured before and after the diets.
  
  
  RESULTS
  The EE response to overfeeding exhibited good intraindividual reproducibility. Similar increases above eucaloric feeding in 24-hour EE (mean 10.7 ± 5.7%, P < .001; range 2.9-18.8%) and sleeping EE (14.4 ± 11.3%, P < .001; range 1.0-45.1%) occurred when overfeeding diets containing 20% protein, despite differences in fat and carbohydrate content, but the EE response during overfeeding diets containing 3% protein was attenuated. The percent body fat negatively correlated with TEF during normal protein overfeeding (r = -0.53, P < .01). Fasting peptide YY negatively correlated with TEF (r = -0.56, P < .01) and the increase in sleeping EE (r = -0.54, P < .01) during overfeeding.
  
  
  CONCLUSIONS
  There is an intrinsic EE response to overfeeding that negatively associates with adiposity, although it represents a small percentage of consumed calories.
authors.affiliation: Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, Arizona 85106, USA. thearlem@mail.nih.gov
authors.forename: Marie S
authors.initials: MS
authors.lastname: Thearle
authors.forename: Nicola
authors.initials: N
authors.lastname: Pannacciulli
authors.forename: Susan
authors.initials: S
authors.lastname: Bonfiglio
authors.forename: Karel
authors.initials: K
authors.lastname: Pacak
authors.forename: Jonathan
authors.initials: J
authors.lastname: Krakoff
mesh_terms: D050154:Adiposity; D000293:Adolescent; D000328:Adult; D001130:Arizona; D002153:Calorimetry, Indirect; D002940:Circadian Rhythm; D059305:Diet, High-Fat; D018753:Diet, Protein-Restricted; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000378:metabolism; D004734:Energy Metabolism; D005215:Fasting / Q000097:blood; D005260:Female; D006801:Humans; D006963:Hyperphagia / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D019894:Peptide YY / Q000097:blood; D015203:Reproducibility of Results; D022722:Thermogenesis; D055815:Young Adult
chemical_list: D004040:Dietary Carbohydrates; D019894:Peptide YY