title: Changes in liver volume and body composition during 4 weeks of low calorie diet before laparoscopic gastric bypass.
abstract: BACKGROUND
  Weight loss before laparoscopic Roux-en-Y gastric bypass (LRYGB) is desirable, because it can reduce liver volume and thereby facilitate the procedure. The optimal duration of a low-calorie diet (LCD) has not been established. The objective of this study was to assess changes in liver volume and body composition during 4 weeks of LCD.
  
  
  METHODS
  Ten women (aged 43±8.9 years, 114±12.1 kg, and body mass index 42±2.6 kg/m(2)) were examined on days 0, 3, 7, 14, and 28 after commencing the LCD. At each evaluation, body composition was assessed through bioelectric impedance analysis, and liver volume and intrahepatic fat content were assessed by magnetic resonance imaging. Serum and urine samples were obtained. Questionnaires regarding quality of life and LCD-related symptoms were administered.
  
  
  RESULTS
  In total, mean weight decreased by 7.4±1.2 kg (range 5.7-9.1 kg), and 71% of the weight loss consisted of fat mass according to bioelectric impedance analysis. From day 0 to day 3, the weight loss (2.0 kg) consisted mainly of water. Liver volume decreased by 18%±6.2%, from 2.1 to 1.7 liters (P<.01), during the first 2 weeks with no further change thereafter. A continuous 51%±16% decrease was seen in intrahepatic fat content. Systolic blood pressure, insulin, and lipids improved, while liver enzymes, glucose levels, and quality of life were unaffected.
  
  
  CONCLUSIONS
  A significant decrease in liver volume (18%) occurred during the first 2 weeks of LCD treatment, and intrahepatic fat gradually decreased throughout the study period. A preoperative 2-week LCD treatment seems sufficient in similar patients.
authors.affiliation: Departments of Surgical Sciences, Uppsala University, Uppsala, Sweden. Electronic address: dedholm@gmail.com.
authors.forename: David
authors.initials: D
authors.lastname: Edholm
authors.affiliation: Departments of Radiology, Oncology, and Radiation Science, Uppsala University, Uppsala, Sweden.
authors.forename: Joel
authors.initials: J
authors.lastname: Kullberg
authors.affiliation: Departments of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: F Anders
authors.initials: FA
authors.lastname: Karlsson
authors.affiliation: Departments of Public Health and Caring Sciences Geriatrics, Uppsala University, Uppsala, Sweden.
authors.forename: Arvo
authors.initials: A
authors.lastname: Haenni
authors.affiliation: Departments of Radiology, Oncology, and Radiation Science, Uppsala University, Uppsala, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Ahlström
authors.affiliation: Departments of Surgical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Sundbom
mesh_terms: D000328:Adult; D001823:Body Composition; D031204:Caloric Restriction / Q000379:methods*; D004038:Diet, Reducing / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass / Q000379:methods*; D006801:Humans; D010535:Laparoscopy; D008099:Liver / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009767:Obesity, Morbid / Q000628:therapy*; D009929:Organ Size; D011184:Postoperative Period; D011446:Prospective Studies; D011788:Quality of Life; D013997:Time Factors; D015431:Weight Loss / Q000502:physiology
keywords: Bioelectric impedance analysis; Intrahepatic fat; Laparoscopic gastric bypass; Low-calorie diet; Magnetic Resonance Imaging; Morbid obesity