BONE METABOLISM IN OBESITY
Location: Grand Forks Human Nutrition Research Center
Title: A high protein diet upregulated whole-body protein turnover during energy deficit
Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 14, 2011
Publication Date: September 29, 2012
Citation: Margolis, L.M., Cao, J.J., Sauter, E.R., Whigham Grendell, L.D., Mcclung, J.P., Combs, G.F., Young, A.J., Pasiakos, S.M. 2012. A high protein diet upregulated whole-body protein turnover during energy deficit. Federation of American Societies for Experimental Biology Conference. 26:1013.3.
The effects of higher protein diets and sustained energy deficit (ED) on whole-body protein turnover (WBPTO) are not well described. This study examined whether dietary protein level influences whole-body protein breakdown (Ra), non-oxidative leucine disposal (NOLD), and oxidation (Ox) during ED. Using a randomized-block design, 24 males and five females (21 ± 3 yr) participated in a controlled trial. Volunteers consumed either standard (SP; 0.8 g•kg-1•d-1), moderate (MP; 1.6 g•kg-1•d-1), or high (HP; 2.4 g•kg-1•d-1) protein diets for 31 days. A weight maintenance (WM, days 1-10) period was followed by 21 days of ED (days 11-31) equal to 40% of total daily energy expenditure. Resting WBPTO (µmol•kg-1·h-1) was determined during WM (day 10) and ED (day 31) using primed, continuous [13C]-leucine infusions. Volunteers lost (P < 0.05) ~ 3.3 ± 1 kg in response to ED regardless of protein level. Ra was decreased (P < 0.05) in response to ED for SP and MP diets, but did not change for HP. NOLD was decreased (P < 0.05) following ED regardless of protein level. Ox increased linearly between SP (9.7 ± 0.5), MP (11.8 ± 0.5), and HP (13.9 ± 0.5) diets during WM, with increased Ox observed only for HP (16 ± 0.7) during ED (diet-by-energy interaction, P < 0.05). These data demonstrate that sustained ED and level of dietary protein intake modulate WBPTO, as consumption of a high protein diet upregulates WBPTO during ED.