scholarly journals An Acute Reduction in Habitual Protein Intake Attenuates Post Exercise Anabolism and May Bias Oxidation-Derived Protein Requirements in Resistance Trained Men

2020 ◽  
Vol 7 ◽  
Author(s):  
Cassidy T. Tinline-Goodfellow ◽  
Daniel W. D. West ◽  
Julia M. Malowany ◽  
Jenna B. Gillen ◽  
Daniel R. Moore
1977 ◽  
Vol 24 (3) ◽  
pp. 307-321 ◽  
Author(s):  
J. F. D. Greenhalgh ◽  
F. W. H. Elsley ◽  
D. A. Grubb ◽  
A. L. Lightfoot ◽  
D. W. Saul ◽  
...  

SUMMARY1. Gestation diets formulated to contain A, 9; B, 11; C, 13 or D, 15% protein, and lactation diets with C, 13 or E, 17% protein provided eight treatment combinations. They were given at seven centres at 2 kg/day in gestation and approximately 5·7 kg/day in lactation to sows which remained on experiment for three to five parities and produced in total 468 litters. Mean results for parities one to four are given in this summary.2. For gestation diets A to D mean litter size at birth was 9·7, 10·1, 10·3 and 10·4 live pigs, and at weaning (at 6 weeks), 8·2, 8·7, 8·8 and 8·8. Sows which received lactation diets C and E subsequently produced 10·4 and 10·3 pigs at birth and 8·9 and 8·3 at weaning.3. Gestation diets had no consistent effects on piglet weights. During lactation, however, diet E gave heavier pigs than C, by 0·2 kg at 3 weeks and 0·5 kg at weaning.4. Extra protein for either gestation or lactation had a positive effect on sow weight at that stage, but a negative effect in the following stage. There were no direct treatment effects on the time required for re-conception.5. Twenty experimental sows at the Rowett Institute, together with an additional group given diet A for both gestation and lactation, showed strong positive relationships between lactation protein intake and milk yield or composition.6. The treatment combination AC (i.e. 9% protein in gestation and 13% in lactation) gave the lowest weight of weaned pigs per litter, and CC gave the highest. The remaining treatments gave similar weights; of these BC (nominally 11 with 13, but actually 11·5 with 13·5% protein) was concluded to provide the lowest protein intake consistent with satisfactory performance.


Nutrients ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 935 ◽  
Author(s):  
Bernhard Franzke ◽  
Oliver Neubauer ◽  
David Cameron-Smith ◽  
Karl-Heinz Wagner

There is an ongoing debate as to the optimal protein intake in older adults. An increasing body of experimental studies on skeletal muscle protein metabolism as well as epidemiological data suggest that protein requirements with ageing might be greater than many current dietary recommendations. Importantly, none of the intervention studies in this context specifically investigated very old individuals. Data on the fastest growing age group of the oldest old (aged 85 years and older) is very limited. In this review, we examine the current evidence on protein intake for preserving muscle mass, strength and function in older individuals, with emphasis on data in the very old. Available observational data suggest beneficial effects of a higher protein intake with physical function in the oldest old. Whilst, studies estimating protein requirements in old and very old individuals based on whole-body measurements, show no differences between these sub-populations of elderly. However, small sample sizes preclude drawing firm conclusions. Experimental studies that compared muscle protein synthetic (MPS) responses to protein ingestion in young and old adults suggest that a higher relative protein intake is required to maximally stimulate skeletal muscle MPS in the aged. Although, data on MPS responses to protein ingestion in the oldest old are currently lacking. Collectively, the data reviewed for this article support the concept that there is a close interaction of physical activity, diet, function and ageing. An attractive hypothesis is that regular physical activity may preserve and even enhance the responsiveness of ageing skeletal muscle to protein intake, until very advanced age. More research involving study participants particularly aged ≥85 years is warranted to better investigate and determine protein requirements in this specific growing population group.


Author(s):  
Nakamura T ◽  

Background and Aims: Patients with Alzheimer’s Disease (AD) frequently develop weight loss. However, little is known about the energy and protein thresholds that cause weight loss. The purpose of this study was to determine the threshold of daily energy and protein requirements to prevent weight loss in patients with AD. Methods: We included 75 Japanese long-term care hospital patients with probable AD (22 men and 53 women, aged 65–101 years) in an interventional study. After a one-week survey using weighed food records weighed food records, the relationship between the obtained energy and protein intake and weight loss after three months was examined. Multiple regression analysis was used to examine the daily determinants of weight loss. Subsequently, receiver operating characteristic curves were used to examine the threshold for discriminating weight loss. Results: Sixty-one (81.3%) patients were malnourished or at risk of malnutrition. Twenty patients (26.7%) had >5% weight loss. The significant associations with weight loss were Mini Nutritional Assessment (MNA) point, energy intake, and protein intake; with a MNA point at cutoff of 17.25, an energy intake at cutoff of 29.93kcal/kg, and a protein intake at cutoff of 1.122g/kg. Conclusion: To prevent weight loss in AD patients, it is important to prevent malnutrition and administer more than 30kcal/kg energy intake and more than 1.1g/kg protein intake. Future studies with a larger sample size are needed to determine the threshold of daily energy and protein requirements to prevent weight loss.


1998 ◽  
Vol 8 (4) ◽  
pp. 426-447 ◽  
Author(s):  
Peter W.R. Lemon

This paper reviews the factors (exercise intensity, carbohydrate availability, exercise type, energy balance, gender, exercise training, age, and timing of nutrient intake or subsequent exercise sessions) thought to influence protein need. Although there remains some debate, recent evidence suggests that dietary protein need increases with rigorous physical exercise. Those involved in strength training might need to consume as much as 1.6 to 1.7 g protein ⋅ kg−1 day−1 (approximately twice the current RDA) while those undergoing endurance training might need about 1.2 to 1.4 g ⋅ kg−1 day−1 (approximately 1.5 times the current RDA). Future longitudinal studies are needed to confirm these recommendations and assess whether these protein intakes can enhance exercise performance. Despite the frequently expressed concern about adverse effects of high protein intake, there is no evidence that protein intakes in the range suggested will have adverse effects in healthy individuals.


2006 ◽  
Vol 16 (4) ◽  
pp. 362-372 ◽  
Author(s):  
Ryan D. Andrews ◽  
David A. MacLean ◽  
Steven E. Riechman

Variability in protein consumption may influence muscle mass changes induced by resistance exercise training (RET). We sought to administer a post-exercise protein supplement and determine if daily protein intake variability affected variability in muscle mass gains. Men (N = 22) and women (N = 30) ranging in age from 60 to 69 y participated in a 12-wk RET program. At each RET session, participants consumed a post-exercise drink (0.4 g/kg lean mass protein). RET resulted in significant increases in lean mass (1.1 ±1.5 kg), similar between sexes (P > 0.05). Variability in mean daily protein intake was not associated with change in lean mass (r < 0.10, P > 0.05). The group with the highest protein intake (1.35 g · kg−1 · d−1, n = 8) had similar (P > 0.05) changes in lean mass as the group with the lowest daily protein intake (0.72 g · kg−1 · d−1, n = 9). These data suggest that variability in total daily protein intake does not affect variability in lean mass gains with RET in the context of post-exercise protein supplementation.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2825 ◽  
Author(s):  
Brad Jon Schoenfeld ◽  
Alan Aragon ◽  
Colin Wilborn ◽  
Stacie L. Urbina ◽  
Sara E. Hayward ◽  
...  

The purpose of this study was to test the anabolic window theory by investigating muscle strength, hypertrophy, and body composition changes in response to an equal dose of protein consumed either immediately pre- versus post-resistance training (RT) in trained men. Subjects were 21 resistance-trained men (>1 year RT experience) recruited from a university population. After baseline testing, participants were randomly assigned to 1 of 2 experimental groups: a group that consumed a supplement containing 25 g protein and 1 g carbohydrate immediately prior to exercise (PRE-SUPP) (n = 9) or a group that consumed the same supplement immediately post-exercise (POST-SUPP) (n = 12). The RT protocol consisted of three weekly sessions performed on non-consecutive days for 10 weeks. A total-body routine was employed with three sets of 8–12 repetitions for each exercise. Results showed that pre- and post-workout protein consumption had similar effects on all measures studied (p > 0.05). These findings refute the contention of a narrow post-exercise anabolic window to maximize the muscular response and instead lends support to the theory that the interval for protein intake may be as wide as several hours or perhaps more after a training bout depending on when the pre-workout meal was consumed.


2003 ◽  
Vol 73 (6) ◽  
pp. 447-452 ◽  
Author(s):  
Boniglia ◽  
Carratù ◽  
Chiarotti ◽  
Giammarioli ◽  
Sanzini

Objectives: Studies relating maternal diet to milk composition in humans have led to contradictory conclusions with regard to protein intake. The purpose of this paper was to examine if differences of protein intake in a group of lactating women can impact the protein and non-protein nitrogen fraction of their milk. Subjects and Methods: Healthy lactating women (117) were recruited in Northern, Central, and Southern Italy. Their anthropometric measurements were obtained one month after delivery, while dietary evaluation was based on two consecutive 24-hour recalls. Infants' growth parameters were measured at birth and at one month. Milk collected at one month was analyzed for content of total nitrogen, protein nitrogen, non-protein nitrogen, and free amino acid profile. Results: Maternal energy intakes were below the recommended values, while protein intakes were higher, with significant differences between geographical areas. There were no differences in the nitrogenous components of the milk examined with the exception of the non-protein nitrogen fraction and serine. Despite the different maternal intakes, no correlations were found between the mothers' parameters and milk components. Conclusion: This study shows that when protein requirements are met and there are no remarkable differences between intakes and requirements, there are no repercussions in nitrogen fractions.


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