title: Changes in total body nitrogen during weight reduction by very-low-calorie diets.
abstract: Body composition measurements, including total body nitrogen (TBN) by in vivo neutron activation analysis, were made on 11 female volunteers before and after an 11-wk very-low-calorie diet (VLCD) [1695 kJ (405 kcal) 6.7 g N]. Mean body mass index (BMI) changed from 32.1 to 26.2 kg/m2, corresponding to a mean weight loss of 16.2 +/- 2.4 (SD) kg. The mean loss of TBN was 125 +/- 57 g, equivalent to 781 +/- 356 g protein. The fat-free mass (FFM) component of the weight loss was calculated by two different methods as 23.5% (+/- 3% SEM) and 22.8% (+/- 2.7% SEM), respectively, thereby demonstrating the improved protein sparing of ketogenic VLCDs. FFM loss was not clearly related to BMI.
authors.affiliation: Department of Medical Physics and Clinical Engineering, Singleton Hospital, Wales, UK.
authors.forename: W D
authors.initials: WD
authors.lastname: Morgan
authors.forename: S J
authors.initials: SJ
authors.lastname: Ryde
authors.forename: J L
authors.initials: JL
authors.lastname: Birks
authors.forename: D W
authors.initials: DW
authors.lastname: Thomas
authors.forename: S N
authors.initials: SN
authors.lastname: Kreitzman
mesh_terms: D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D004038:Diet, Reducing; D002149:Energy Intake / Q000502:physiology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009501:Neutron Activation Analysis; D009584:Nitrogen / Q000378:metabolism*; D009765:Obesity / Q000178:diet therapy*; D015431:Weight Loss / Q000502:physiology*
chemical_list: D009584:Nitrogen