Mon, Aug-29-16, 05:40
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Senior Member
Posts: 15,075
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Plan: mostly milkfat
Stats: 190/152.4/154
BF:
Progress: 104%
Location: Ontario
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Even when you get to weight training and protein requirements, things are a bit uncertain. You can have a study where somebody at say 60 grams of protein a day experiences slower muscle growth than somebody at 100 grams. So did the exercise increase protein requirements? Not necessarily--remove the exercise, and instead of slow muscle growth, the person at 60 grams might have experienced instead no muscle growth or actual loss. You could look at that as the protein increasing this specific benefit from the exercise, rather than the exercise increasing the requirement for the protein. The question might be what's optimal, rather than what's required.
cottonpal said;
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We recently had a discussion here about higher protein requirements for older people and protein requirements vary depending on how much exercise you get.
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Speaking of this--during that discussion I meant to mention this study but got distracted;
http://ajcn.nutrition.org/content/69/6/1202.full
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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.
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http://www.ncbi.nlm.nih.gov/pubmed/22992307
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Impact of protein pulse feeding on lean mass in malnourished and at-risk hospitalized elderly patients: a randomized controlled trial.
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BACKGROUND & AIMS:
Aging is associated with a blunted anabolic response to dietary intake, possibly related to a decrease in systemically available amino acids (AAs), which in turn may stem from increased splanchnic AA metabolism. This splanchnic sequestration can be saturated by pulse feeding (80% of daily protein intake in a single meal), enabling increased protein synthesis. This study aimed to evaluate the efficacy of a new nutritional strategy, termed protein pulse feeding.
METHODS:
This prospective randomized study (ClinicalTrials.gov registration number NCT00135590) enrolled 66 elderly malnourished or at-risk patients in an inpatient rehabilitation unit. All were given a controlled diet for 6 weeks. In a spread diet (SD) group (n = 36), dietary protein was spread over the four daily meals. In a pulse diet (PD) group (n = 30), 72% of dietary protein (1.31 g/kg weight/d on average) was consumed in one meal at noon. The patients were evaluated at admission and at 6 weeks for body composition [lean mass (LM), appendicular skeletal muscle mass (ASMM), and body cell mass (BCM) indices, measured by X-ray absorptiometry combined with bioelectrical impedance analysis] (primary outcome), hand grip strength, and activities of daily living (ADL) score.
RESULTS:
Protein pulse feeding was significantly more efficacious than protein spread feeding in improving LM index (mean changes from baseline for PD group: +0.38 kg/m(2); 95% confidence interval (CI), [0; 0.60]; for SD group: -0.21 kg/m(2); 95% CI, [-0.61; 0.20]; p = 0.005 between the two groups), ASMM index (+0.21 kg/m(2); 95% CI, [0; 0.34] and -0.11 kg/m(2); 95% CI, [-0.20; 0.09]; p = 0.022), BCM index (+0.44 kg/m(2); 95% CI, [0.08; 0.52] and -0.04 kg/m(2); 95% CI, [-0.09; 0.10]; p = 0.004). There was no significant effect for hand-grip strength or ADL score.
CONCLUSIONS:
This study demonstrates for the first time that protein pulse feeding has a positive, clinically relevant effect on lean mass in malnourished and at-risk hospitalized elderly patients.
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Past a certain age, a bigger protein meal might be better than a bunch of little ones.
Here I wonder whether besides a stronger signal from a larger protein meal, there might be a sensitizing effect due to the fact that this leaves protein intake sort of low during the rest of the day. If you take the first study--somebody taking in 80 grams of protein in a pulse fashion would be getting 64 grams in the big meal, with only 16 grams for the rest of the day.
I'm a bit skeptical of the methods of measuring lean mass in both studies, so at this point I still find this interesting and promising rather than convincing. The downside of trying something like this seems low, though.
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