BACKGROUND/ OBJECTIVES: We intended to (i) to compare the composition of weight loss and weight gain using densitometry, deuterium dilution (D₂O), dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI) and the four-compartment (4C) model and (ii) to compare regional changes in fat mass (FM), fat-free mass (FFM) and skeletal muscle as assessed by DXA and MRI. SUBJECTS/ METHODS: Eighty-three study participants aged between 21 and 58 years with a body mass index range of 20.2-46.8 kg/m(2) had been assessed at two different occasions with a mean follow-up between 23.5 and 43.5 months. Body-weight changes within < 3% were considered as weight stable, a gain or a loss of >3% of initial weight was considered as a significant weight change. RESULTS: There was a considerable bias between the body-composition data obtained by the individual methods. When compared with the 4C model, mean bias of D₂O and densitometry was explained by the erroneous assumption of a constant hydration of FFM, thus, changes in FM were underestimated by D₂O but overestimated by densitometry. Because hydration does not normalize after weight loss, all two-component models have a systematic error in weight-reduced subjects. The bias between 4C model and DXA was mainly explained by FM% at baseline, whereas FFM hydration contributed to additional 5%. As to the regional changes in body composition, DXA data had a considerable bias and, thus, cannot replace MRI. CONCLUSIONS: To assess changes in body composition associated with weight changes, only the 4C model and MRI can be used with confidence.
BACKGROUND/ OBJECTIVES: We intended to (i) to compare the composition of weight loss and weight gain using densitometry, deuterium dilution (D₂O), dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI) and the four-compartment (4C) model and (ii) to compare regional changes in fat mass (FM), fat-free mass (FFM) and skeletal muscle as assessed by DXA and MRI. SUBJECTS/ METHODS: Eighty-three study participants aged between 21 and 58 years with a body mass index range of 20.2-46.8 kg/m(2) had been assessed at two different occasions with a mean follow-up between 23.5 and 43.5 months. Body-weight changes within < 3% were considered as weight stable, a gain or a loss of >3% of initial weight was considered as a significant weight change. RESULTS: There was a considerable bias between the body-composition data obtained by the individual methods. When compared with the 4C model, mean bias of D₂O and densitometry was explained by the erroneous assumption of a constant hydration of FFM, thus, changes in FM were underestimated by D₂O but overestimated by densitometry. Because hydration does not normalize after weight loss, all two-component models have a systematic error in weight-reduced subjects. The bias between 4C model and DXA was mainly explained by FM% at baseline, whereas FFM hydration contributed to additional 5%. As to the regional changes in body composition, DXA data had a considerable bias and, thus, cannot replace MRI. CONCLUSIONS: To assess changes in body composition associated with weight changes, only the 4C model and MRI can be used with confidence.
Authors: Kevin D Hall; Thomas Bemis; Robert Brychta; Kong Y Chen; Amber Courville; Emma J Crayner; Stephanie Goodwin; Juen Guo; Lilian Howard; Nicolas D Knuth; Bernard V Miller; Carla M Prado; Mario Siervo; Monica C Skarulis; Mary Walter; Peter J Walter; Laura Yannai Journal: Cell Metab Date: 2015-08-13 Impact factor: 27.287
Authors: Kevin D Hall; Alexis Ayuketah; Robert Brychta; Hongyi Cai; Thomas Cassimatis; Kong Y Chen; Stephanie T Chung; Elise Costa; Amber Courville; Valerie Darcey; Laura A Fletcher; Ciaran G Forde; Ahmed M Gharib; Juen Guo; Rebecca Howard; Paule V Joseph; Suzanne McGehee; Ronald Ouwerkerk; Klaudia Raisinger; Irene Rozga; Michael Stagliano; Mary Walter; Peter J Walter; Shanna Yang; Megan Zhou Journal: Cell Metab Date: 2019-05-16 Impact factor: 27.287
Authors: Kevin D Hall; Juen Guo; Kong Y Chen; Rudolph L Leibel; Marc L Reitman; Michael Rosenbaum; Steven R Smith; Eric Ravussin Journal: Am J Clin Nutr Date: 2019-05-01 Impact factor: 7.045
Authors: Abigail J Johnson; James R Matthie; Adam Kuchnia; Levi M Teigen; Lauren M Beckman; Jennifer R Mager; Sarah A Nicklay; Urvashi Mulasi; Shalamar D Sibley; Emily Nagel; Carrie P Earthman Journal: BRASPEN J Date: 2017 Jul-Sep
Authors: Gordon I Smith; Paul K Commean; Dominic N Reeds; Samuel Klein; Bettina Mittendorfer Journal: Obesity (Silver Spring) Date: 2018-05 Impact factor: 5.002