title: Changes in body composition with weight loss: obese subjects randomized to surgical and medical programs.
abstract: OBJECTIVE
  To assess changes in body composition with weight loss in obese subjects randomized to a laparoscopic adjustable gastric band surgical program or a medical program using a very-low-energy diet and orlistat.
  
  
  METHODS
  Using body composition measurements by DXA, neutron activation for total body nitrogen, and whole body gamma counting for total body potassium, we studied changes in fat mass, fat distribution, fat-free mass, total bone mineral content, total body protein, and body cell mass at 6 (n = 61 paired) and 24 months (n = 53 paired) after randomization.
  
  
  RESULTS
  At 24 months, the surgical group had lost significantly more weight (surgical, 20.3 +/- 6.5 kg; medical, 5.9 +/- 8.0 kg). There was favorable fat-free mass to fat mass loss ratios for both groups (surgical, 1:5.5; medical, 1:5.9). Changes in total body nitrogen or potassium were favorable in each group. A small reduction in mean bone mineral content occurred throughout the study but was not associated with extent of weight loss or treatment group. At 6 months, weight loss for both groups was similar (surgical, 14.1 +/- 4.5 kg; medical, 13.3 +/- 7.3 kg). The medical program subjects lost less fat-free mass and skeletal muscle and had increased total body protein. The proportion of body fat to limb fat remained remarkably constant throughout the study.
  
  
  CONCLUSIONS
  Weight loss programs used in this study induced fat loss without significant deleterious effects on the components of fat-free mass.
authors.affiliation: Centre for Obesity Research and Education, Monash Medical School, The Alfred Hospital, Melbourne, Victoria, Australia 3004. john.dixon@med.monash.edu.au
authors.forename: John B
authors.initials: JB
authors.lastname: Dixon
authors.forename: Boyd J G
authors.initials: BJ
authors.lastname: Strauss
authors.forename: Cheryl
authors.initials: C
authors.lastname: Laurie
authors.forename: Paul E
authors.initials: PE
authors.lastname: O'Brien
mesh_terms: D000328:Adult; D001067:Appetite Depressants / Q000627:therapeutic use*; D001823:Body Composition; D004038:Diet, Reducing; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D007783:Lactones / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology*; D009765:Obesity / Q000188:drug therapy* / Q000601:surgery*; D000077403:Orlistat; D015431:Weight Loss
chemical_list: D001067:Appetite Depressants; D007783:Lactones; D000077403:Orlistat