title: Energy, substrate and protein metabolism in morbid obesity before, during and after massive weight loss.
abstract: OBJECTIVE
  To investigate the effect of surgically induced weight loss on energy, substrate and protein metabolism of morbidly obese patients.
  
  
  METHODS
  A prospective, clinical intervention study of morbidly obese patients before and after surgical treatment.
  
  
  METHODS
  Eight morbidly obese patients (BMI 47.88+/-7.03).
  
  
  METHODS
  Total energy expenditure (TEE; doubly labeled water method), sleeping metabolic rate (SMR; respiration chamber), body composition (deuterium oxide component of doubly labeled water), substrate metabolism (48 h dietary records, 48 h urine collection and gaseous exchange in the respiration chamber) and whole body protein turnover (primed-continuous infusion of L-[1-13C]-leucine) were measured before, 3 and 12 months after vertical banded gastroplasty (VBG).
  
  
  RESULTS
  The TEE decreased as a result of a decreased SMR (64%) and non-SMR (36%; P=0.001). SMR as a function of fat-free mass (FFM) decreased after weight loss (P<0.05). The physical activity index (PAI), defined as TEE/SMR, was low and was not influenced by weight loss. Protein and carbohydrate oxidation decreased significantly after VBG (P<0.05), although 3 months after VBG protein oxidation did not decrease enough to prevent loss of FFM. The energy used for protein turnover was approximately 24% of SMR and did not change after weight loss.
  
  
  CONCLUSIONS
  Compensatory processes that oppose weight loss of morbidly obese patients exist, as demonstrated by the disproportional reduction of SMR, and a low PAI. Protein turnover is not a major contributor to the disproportional reduction of SMR.
authors.affiliation: Departments of Surgery and Human Biology, University Hospital Maastricht, PO box 5800, 6202 AZ, Maastricht, The Netherlands. wg.gemert@wxs.nl
authors.forename: W G
authors.initials: WG
authors.lastname: van Gemert
authors.forename: K R
authors.initials: KR
authors.lastname: Westerterp
authors.forename: B A
authors.initials: BA
authors.lastname: van Acker
authors.forename: A J
authors.initials: AJ
authors.lastname: Wagenmakers
authors.forename: D
authors.initials: D
authors.lastname: Halliday
authors.forename: J M
authors.initials: JM
authors.lastname: Greve
authors.forename: P B
authors.initials: PB
authors.lastname: Soeters
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000328:Adult; D001481:Basal Metabolism; D001823:Body Composition; D015992:Body Mass Index; D015930:Diet Records; D004734:Energy Metabolism; D005260:Female; D015391:Gastroplasty; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000378:metabolism* / Q000601:surgery*; D010101:Oxygen Consumption; D011506:Proteins / Q000378:metabolism*; D015431:Weight Loss
chemical_list: D011506:Proteins; D000255:Adenosine Triphosphate