BACKGROUND: The effect of the recent obesity epidemic on body composition remains unknown. Furthermore, age-related changes in body composition are still unclear. OBJECTIVE: The objective was to simultaneously examine the effects of birth cohort and age on body composition. DESIGN: A total of 1786 well-functioning, community-based whites and blacks (52% women and 35% blacks) aged 70-79 y from the Health, Aging, and Body Composition Study underwent dual-energy X-ray absorptiometry annually from 1997 to 2003. RESULTS: At baseline, mean +/- SD percentage body fat, fat mass, and lean mass (bone-free) were 28 +/- 5%, 24 +/- 7 kg, and 56 +/- 7 kg, respectively, for men and 39 +/- 6%, 28 +/- 9 kg, and 40 +/- 6 kg for women. Mixed models were used to assess the effects of cohort and age-related changes on body composition. Later cohorts in men had a greater percentage body fat (0.32% per birth year, P < 0.0001) than did earlier cohorts. This cohort effect was due to a greater increase in fat mass than in lean mass (0.45 kg and 0.17 kg/birth year, respectively). With increasing age, percentage body fat in men initially increased and then leveled off. This age-related change was due to an accelerated decrease in lean mass and an initial increase and a later decrease in fat mass. Similar but less extreme effects of cohort and age were observed in women. CONCLUSIONS: The combination of effects of both birth cohort and age leads to bigger body size and less lean mass in the elderly.
BACKGROUND: The effect of the recent obesity epidemic on body composition remains unknown. Furthermore, age-related changes in body composition are still unclear. OBJECTIVE: The objective was to simultaneously examine the effects of birth cohort and age on body composition. DESIGN: A total of 1786 well-functioning, community-based whites and blacks (52% women and 35% blacks) aged 70-79 y from the Health, Aging, and Body Composition Study underwent dual-energy X-ray absorptiometry annually from 1997 to 2003. RESULTS: At baseline, mean +/- SD percentage body fat, fat mass, and lean mass (bone-free) were 28 +/- 5%, 24 +/- 7 kg, and 56 +/- 7 kg, respectively, for men and 39 +/- 6%, 28 +/- 9 kg, and 40 +/- 6 kg for women. Mixed models were used to assess the effects of cohort and age-related changes on body composition. Later cohorts in men had a greater percentage body fat (0.32% per birth year, P < 0.0001) than did earlier cohorts. This cohort effect was due to a greater increase in fat mass than in lean mass (0.45 kg and 0.17 kg/birth year, respectively). With increasing age, percentage body fat in men initially increased and then leveled off. This age-related change was due to an accelerated decrease in lean mass and an initial increase and a later decrease in fat mass. Similar but less extreme effects of cohort and age were observed in women. CONCLUSIONS: The combination of effects of both birth cohort and age leads to bigger body size and less lean mass in the elderly.
Authors: Fahad Javed; Emad F Aziz; Manpreet S Sabharwal; Girish N Nadkarni; Shahzeb A Khan; Juan P Cordova; Alexandre M Benjo; Dympna Gallagher; Eyal Herzog; Franz H Messerli; F Xavier Pi-Sunyer Journal: Obesity (Silver Spring) Date: 2010-12-23 Impact factor: 5.002
Authors: Sari Stenholm; Tamara B Harris; Taina Rantanen; Marjolein Visser; Stephen B Kritchevsky; Luigi Ferrucci Journal: Curr Opin Clin Nutr Metab Care Date: 2008-11 Impact factor: 4.294
Authors: Alfonso J Cruz-Jentoft; Jean Pierre Baeyens; Jürgen M Bauer; Yves Boirie; Tommy Cederholm; Francesco Landi; Finbarr C Martin; Jean-Pierre Michel; Yves Rolland; Stéphane M Schneider; Eva Topinková; Maurits Vandewoude; Mauro Zamboni Journal: Age Ageing Date: 2010-04-13 Impact factor: 10.668
Authors: Powen Tu; Shalender Bhasin; Paul W Hruz; Karen L Herbst; Lawrence W Castellani; Ning Hua; James A Hamilton; Wen Guo Journal: Diabetes Date: 2009-06-09 Impact factor: 9.461