title: Assessment of the body composition and the loss of fat-free mass through bioelectric impedance analysis in patients who underwent open gastric bypass.
abstract: BACKGROUND
  Bariatric surgery is considered an effective option for the management of morbid obesity. The incidence of obesity has been gradually increasing all over the world reaching epidemic proportions in some regions of the world. Obesity can cause a reduction of up to 22% in the life expectancy of morbidly obese patients.
  
  
  OBJECTIVE
  The objective of this paper is to assess the weight loss associated with the first 6 months after bariatric surgery using bioelectric impedance analysis (BIA) for the evaluation of fat mass and fat-free mass.
  
  
  METHODS
  A total of 36 morbidly obese patients were subjected to open gastric bypass surgery. The patients weight was monitored before and after the procedure using the bioelectric impedance analysis.
  
  
  RESULTS
  Bariatric surgery resulted in an average percentage of weight loss of 28.6% (40 kg) as determined 6 months after the procedure was performed. Analysis of the different components of body weight indicated an undesirable loss of fat-free mass along with the reduction of total body weight.
  
  
  CONCLUSIONS
  Open gastric bypass induced a significant loss of total weight and loss of fat-free mass in patients six months after the surgery. The use of bioelectric impedance analysis resulted in an appropriate estimation of the total weight components in individuals subjected to bariatric surgery allowing a more real analysis of the variation of weight after the surgery.
authors: Gastric Surgery Division, Department of Surgery of Santa Casa of São Paulo Medical School, São Paulo, SP, Brazil.
authors: Wilson Rodrigues
authors: WR
authors: de Freitas Junior
authors: Gastric Surgery Division, Department of Surgery of Santa Casa of São Paulo Medical School, São Paulo, SP, Brazil.
authors: Elias Jirjoss
authors: EJ
authors: Ilias
authors: Gastric Surgery Division, Department of Surgery of Santa Casa of São Paulo Medical School, São Paulo, SP, Brazil.
authors: Paulo
authors: P
authors: Kassab
authors: Gastric Surgery Division, Department of Surgery of Santa Casa of São Paulo Medical School, São Paulo, SP, Brazil.
authors: Roberto
authors: R
authors: Cordts
authors: Gastric Surgery Division, Department of Surgery of Santa Casa of São Paulo Medical School, São Paulo, SP, Brazil.
authors: Paulo Gustavo
authors: PG
authors: Porto
authors: Gastric Surgery Division, Department of Surgery of Santa Casa of São Paulo Medical School, São Paulo, SP, Brazil.
authors: Francisco Cesar
authors: FC
authors: Martins Rodrigues
authors: Gastric Surgery Division, Department of Surgery of Santa Casa of São Paulo Medical School, São Paulo, SP, Brazil.
authors: Mohamed Ibrahim
authors: MI
authors: Ali Taha
authors: Department of Epidemiology of Santa Casa of São Paulo Medical School, São Paulo, SP, Brazil.
authors: Paulo
authors: P
authors: Carrara
authors: Master's and Doctoral Programs in Rehabilitation Sciences, Nove de Julho University (UNINOVE), São Paulo, SP, Brazil.
authors: Isabella
authors: I
authors: de Carvalho Aguiar
authors: Master's and Doctoral Programs in Rehabilitation Sciences, Nove de Julho University (UNINOVE), São Paulo, SP, Brazil.
authors: Luis Vicente Franco
authors: LV
authors: de Oliveira
authors: Gastric Surgery Division, Department of Surgery of Santa Casa of São Paulo Medical School, São Paulo, SP, Brazil.
authors: Osvaldo
authors: 0000-0002-5251-528X
authors: O
authors: Castro
authors: Gastric Surgery Division, Department of Surgery of Santa Casa of São Paulo Medical School, São Paulo, SP, Brazil.
authors: Carlos Alberto
authors: CA
authors: Malheiros
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D017097:Electric Impedance; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors