title: Changes in body fat: measurements by neutron activation, densitometry and dual energy X-ray absorptiometry.
abstract: The measurement of body fat in ten subjects (BMI from 22 to 43 kg/m2), and in particular the changes arising from a ketogenic diet, by the techniques of in vivo neutron activation analysis (NAA), densitometry (using two- and four-compartment models) by under water weighing (UWW) and dual energy X-ray absorptiometry (DXA) was compared. The association between techniques for the fat changes was generally high (r = 0.70 to 0.98) and significant (p < 0.05). Assessment of agreement between DXA and the other techniques revealed discrepancies with significant slope and high association (r = -0.81 and -0.64). Whilst NAA and UWW appeared to measure similar changes, DXA underestimated small changes.
authors.affiliation: Department of Medical Physics and Clinical Engineering, Singleton Hospital, Swansea, U.K.
authors.forename: S J
authors.initials: SJ
authors.lastname: Ryde
authors.forename: R
authors.initials: R
authors.lastname: Eston
authors.forename: M A
authors.initials: MA
authors.lastname: Laskey
authors.forename: C J
authors.initials: CJ
authors.lastname: Evans
authors.forename: D A
authors.initials: DA
authors.lastname: Hancock
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000273:Adipose Tissue / Q000033:anatomy & histology*; D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D003720:Densitometry / Q000379:methods; D004038:Diet, Reducing; D005260:Female; D006801:Humans; D007101:Immersion; D008875:Middle Aged; D008954:Models, Biological; D009501:Neutron Activation Analysis / Q000379:methods; D015431:Weight Loss