Premium
Leucine balance, metabolic and satiety responses to a leucinerich meal in healthy elderly women
Author(s) -
Snarr Chandra,
Redmond Emily,
Morais José A.,
Wykes Linda J.,
Chevalier Stéphanie
Publication year - 2012
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.26.1_supplement.42.7
Subject(s) - leucine , postprandial , anabolism , appetite , endocrinology , medicine , meal , crossover study , ghrelin , peptide yy , chemistry , insulin , amino acid , hormone , biochemistry , neuropeptide , placebo , alternative medicine , receptor , pathology , neuropeptide y receptor
Many older adults experience a decline of appetite and may not meet their protein needs; a strategy to optimize protein retention is thus essential. Leucine has anabolic potential by stimulating protein synthesis via mRNA translation and insulin secretion. Postprandial responses to leucine‐rich versus isonitrogenous mixed meals were assessed in 9 healthy older women (70.1±2 y, BMI 23.7±2.7 kg/m 2 ) by double‐blinded, randomized, crossover studies. Test meals provided 0.6 g protein and 16.0 kcal/kg LBM, once with added leucine (0.07 g/kg LBM), once without. Results Five‐hour whole‐body postprandial leucine oxidation response, measured by constant infusion of [1‐ 13 C]leucine and enrichment of plasma 13 C‐KIC and expired 13 CO 2 was further increased with meal+leucine. Yet, the resulting balance (intake‐oxidation) was greater (18.1±1.4 vs. without 11.3±1.3 mmol/5h, p<0.001) suggesting more protein retention. Serum insulin and C‐peptide AUC were greater post meal+leucine, indicating more secretion. Plasma glucose excursions and free fatty acids suppression did not differ between meals. Addition of leucine had no effect on meal‐induced thermogenesis, satiety and gut peptide responses (GLP‐1, PYY 3–36, ghrelin). This study shows the anabolic potential of a leucine‐rich mixed meal in older women, a dietary strategy that may be used to promote protein anabolism without affecting appetite. (Funded by CIHR)