Protein pulse feeding improves protein retention in elderly women

Abstract

Background: Adequate protein nutrition could be used to limit gradual body protein loss and improve protein anabolism in the elderly. Objective: We tested the hypothesis that an uneven protein feeding pattern was more efficient in improving protein anabolism than was an even pattern. Design: After a controlled period, 15 elderly women (mean age: 68 y) were fed for 14 d either a pulse diet (n = 7), providing 80% of the daily protein intake at 1200, or a spread diet (n = 8), in which the same daily protein intake was spread over 4 meals. Both diets provided 1.7 g protein · kg fat-free mass (FFM)-1 · d-1. Protein accretion and daily protein turnover were determined by using the nitrogen balance method and the end product method (ammonia and urea) after an oral dose of [15N]glycine. Results: Nitrogen balance was more positive with the pulse than with the spread diet (54 ± 7 compared with 27 ± 6 mg N · kg FFM-1 · d-1; P < 0.05). Protein turnover rates were also higher with the pulse than with the spread diet (5.58 ± 0.22 compared with 4.98 ± 0.17 g protein · kg FFM-1 · d-1; P < 0.05), mainly because of higher protein synthesis in the pulse group (4.48 ± 0.19 g protein · kg FFM-1 · d-1) than in the spread group (3.75 ± 0.19 g protein · kg FFM-1 · d-1) (P < 0.05). Conclusion: A protein pulse-feeding pattern was more efficient than was a protein spread-feeding pattern in improving, after 14 d, whole-body protein retention in elderly women.