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Carbohydrate energy‐replacement attenuates protein turnover and promotes nitrogen retention during acute periods of increased metabolic demand (820.8)
Author(s) -
McClung Holly,
Lin Greg,
Smith Tracey,
Bukhari Asma,
Lieberman Harris,
Pasiakos Stefan
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.820.8
Subject(s) - protein turnover , nitrogen balance , carbohydrate , chemistry , energy balance , medicine , flux (metallurgy) , endocrinology , protein catabolism , nitrogen , zoology , biochemistry , biology , protein biosynthesis , amino acid , ecology , organic chemistry
Acute periods of increased metabolic demand and subsequent energy deficit increase protein loss. To examine whether consuming an energy‐replacement based primarily on carbohydrate (85%) with negligible protein (2%) attenuates protein loss during highly metabolic energy flux, whole‐body protein turnover ( 15 N‐glycine) was measured in 23 adults at baseline and after 2‐days of increased metabolic energy expenditure ([mean ± SD] 1800 ± 350 kcal·d ‐1 ) once in energy balance (BAL) and on a separate occasion during energy deficit (DEF, 90%). Turnover was the same at baseline for both trials. After DEF, protein flux, synthesis, and breakdown rates were higher and net balance was lower than after BAL (time‐by‐energy , P < 0.05). Within trials, protein flux decreased for BAL but remained constant for DEF (time‐by‐energy, P < 0.05). Synthesis and breakdown decreased over time during BAL, whereas synthesis remained steady and breakdown increased 36% during DEF (time‐by‐energy, P < 0.05). Thus, net protein balance was maintained during BAL but was negative at the end of DEF (‐0.7 ± 0.4 g·kg ‐1 ·d ‐1 ; time‐by‐energy, P < 0.05). These data confirm the detrimental effects of energy deficit on protein balance and indicate that, by attenuating protein turnover, a carbohydrate‐based energy replacement can promote nitrogen retention during acute periods of increased metabolic demand. Grant Funding Source : USAMRMC and DMRDP