Protein Intake Timing

Here is a paper from several years ago that asserts that protein intake distribution – consuming most of the protein at one meal or spreading it out more evenly throughout the day – does not affect muscle building.  Hence the authors conclude:

We conclude that over an 8-week intervention period, the protein intake distribution pattern in mixed meals does not play an important role in determining anabolic response, muscle strength, or functional outcomes. 

One caveat is that it is uncertain whether the subjects were doing any resistance exercising. For example, you may expect to observe better results consuming a lot of protein just after the workout (and/or before and after) than distributed throughout the day, but this needs to be confirmed.  If the subjects were just regularly active, then perhaps intake time does not matter.  More study is required.

Carbs And Protein For Muscle Recovery

A paper from several years ago supports the traditional wisdom for post-workout muscle recover, abstract:

The objective of the study was to investigate whether co-ingestion of carbohydrate and protein as compared with protein alone augments muscle protein synthesis (MPS) during early exercise recovery. Two months old rats performed 10 repetitions of ladder climbing with 75% of body weight attached to their tails. Placebo (PLA), whey protein (WP), or whey protein plus carbohydrate (CP) was then given to rats by gavage. An additional group of sedentary rats (SED) was used as controls. Blood samples were collected immediately and at either 1 or 2 h after exercise. The flexor hallucis longus muscle was excised at 1 or 2 h post exercise for analysis of MPS and related signaling proteins. MPS was significantly increased by CP compared with PLA (p<0.05), and approached significance compared with WP at 1 h post exercise (p = 0.08). CP yielded a greater phosphorylation of mTOR compared with SED and PLA at 1 h post exercise and SED and WP at 2 h post exercise. CP also increased phosphorylation of p70S6K compared with SED at 1 and 2 h post exercise. 4E-BP1 phosphorylation was inhibited by PLA at 1 h but elevated by WP and CP at 2 h post exercise relative to SED. The phosphorylation of AMPK was elevated by exercise at 1 h post exercise, and this elevated level was sustained only in the WP group at 2 h. The phosphorylation of Akt, GSK3, and eIF2Bε were unchanged by treatments. Plasma insulin was transiently increased by CP at 1 h post exercise. In conclusion, post-exercise CP supplementation increases MPS post exercise relative to PLA and possibly WP, which may have been mediated by greater activation of the mTOR signaling pathway

Carbs and protein post-resistance training therefore proved here superior to protein alone.

Resistance Training Restores Muscle Sensitivity To Feeding

An interesting paper on exercise, feeding, and muscle; abstract:

Normally, skeletal muscle mass is unchanged, beyond periods of growth, but it begins to decline in the fourth or fifth decade of life. The mass of skeletal muscle is maintained by ingestion of protein-containing meals. With feeding, muscle protein synthesis (MPS) is stimulated and a small suppression of muscle protein breakdown (MPB) occurs, such that protein balance becomes positive (MPS>MPB). As the postprandial period subsides and a transition toward fasting occurs, the balance of muscle protein turnover becomes negative again (MPB>MPS). Thus, during maintenance of skeletal muscle mass, the long-term net result is that MPS is balanced by MPB. Acutely, however, it is of interest to determine what regulates feeding-induced increases in MPS, since it appears that, in a number of scenarios (for example aging, disuse, and wasting diseases), a suppression of MPS in response to feeding is a common finding. In fact, recent findings point to the fact that loss of skeletal muscle mass with disuse and aging is due not chronic changes in MPS or MPB, but to a blunted feeding-induced rise in MPS. Resistance exercise is a potent stimulator of MPS and appears to synergistically enhance the gains stimulated by feeding. As such, resistance exercise is an important countermeasure to disuse atrophy and to age-related declines in skeletal muscle mass. What is less well understood is how the intensity and volume of the resistance exercise stimulus is sufficient to result in rises in MPS. Recent advances in this area are discussed here, with a focus on human in vivo data.

To summarize: feeding, particularly of protein, favors muscle buildup as opposed t breakdown and fasting does the opposite.  Muscle loss with age seems linked to suppressed muscle buildup from feeding and this suppression can be reduced by resistance training.  Therefore, resistance training helps to reduce/prevent age-related muscle loss, possibly through enhancing feeding-related stimulation of muscle protein synthesis.  Hence the importance of resistance training and (protein) feeding (albeit of course not in excess).

Resistance Training And Muscle Metabolism

Here is a paper from several years ago formally demonstrating what bodybuilders have long put into practice: resistance training affects protein turnover in skeletal muscle so as to result in muscle growth.  Abstract:

PURPOSE:

Acute bouts of resistance exercise and subsequent training alters protein turnover in skeletal muscle. The mechanisms responsible for the changes in basal post-absorptive protein turnover and its impact on muscle hypertrophy following resistance exercise training are unknown. Our goal was to determine whether post-absorptive muscle protein turnover following 12 weeks of resistance exercise training (RET) plays a role in muscle hypertrophy. In addition, we were interested in determining potential molecular mechanisms responsible for altering post-training muscle protein turnover.

METHODS:

Healthy young men (n = 31) participated in supervised whole body progressive RET at 60-80% 1 repetition maximum (1-RM), 3 days/week for 3 months. Pre- and post-training vastus lateralis muscle biopsies and blood samples taken during an infusion of 13C6 and 15N phenylalanine and were used to assess skeletal muscle protein turnover in the post-absorptive state. Lean body mass (LBM), muscle strength (determined by dynamometry), vastus lateralis muscle thickness (MT), myofiber type-specific cross-sectional area (CSA), and mRNA were assessed pre- and post-RET.

RESULTS:

RET increased strength (12-40%), LBM (~5%), MT (~15%) and myofiber CSA (~20%) (p < 0.05). Muscle protein synthesis (MPS) increased 24% while muscle protein breakdown (MPB) decreased 21%, respectively. These changes in protein turnover resulted in an improved net muscle protein balance in the basal state following RET. Further, the change in basal MPS is positively associated (r = 0.555, p = 0.003) with the change in muscle thickness.

CONCLUSION:

Post-absorptive muscle protein turnover is associated with muscle hypertrophy during resistance exercise training.

It is always comforting when science supports popular conception.

Maintaining Lean Body Mass While "Cutting"

A regimen for maintaining lean body mass while "cutting" for a drug-free physique competition was studied in a female competitor.  Abstract:

To achieve the criterion appearance prior to competing in a physique competition, athletes undergo preparatory regimens involving high-volume intense resistance and aerobic exercise with hypocaloric energy intake. As the popularity of "drug-free" competition increases, more athletes are facing this challenge without the recuperative advantage provided by performance-enhancing drugs. Consequently, the likelihood of loss of lean body and/or bone mass is increased. The purpose of this investigation was to monitor changes in body composition for a 29-year-old self-proclaimed drug-free female figure competitor during a 32-week preparatory regimen comprising high-volume resistance and aerobic exercise with hypocaloric energy intake. We used dual-energy x-ray absorptiometry (DXA) to evaluate regional fat and bone mineral density. During the initial 22 weeks, the subject reduced energy intake and engaged in resistance (4-5 sessions/week) and aerobic (3 sessions/week) training. During the final 10 weeks, the subject increased exercise frequency to 6 (resistance) and 4 (aerobic) sessions/week while ingesting 1130-1380 kcal/day. During this 10-week period, she consumed a high quantity of protein (~55% of energy intake) and nutritional supplements. During the 32 weeks, body mass and fat mass decreased by 12% and 55%, respectively. Conversely, lean body mass increased by 1.5%, an amount that exceeded the coefficient of variation associated with DXA-derived measurement. Total bone mineral density was unchanged throughout. In summary, in preparation for a figure competition, a self-proclaimed drug-free female achieved the low body-fat percentage required for success in competition without losing lean mass or bone density by following a 32-week preparatory exercise and nutritional regimen.

Thus, consistent with popular conception, a high protein intake was associated with maintenance (actually increase) with decreased body mass and fat mass.  High volume exercise and calorie-cutting were all part of the mix, also consistent with popular practice.

Protein Glycosylation Targeting Immunotherapy

Another approach for anti-cancer immunotherapy, abstract:

Protein glycosylation provides proteomic diversity in regulating protein localization, stability, and activity; it remains largely unknown whether the sugar moiety contributes to immunosuppression. In the study of immune receptor glycosylation, we showed that EGF induces programmed death ligand 1 (PD-L1) and receptor programmed cell death protein 1 (PD-1) interaction, requiring β-1,3-N-acetylglucosaminyl transferase (B3GNT3) expression in triple-negative breast cancer. Downregulation of B3GNT3 enhances cytotoxic T cell-mediated anti-tumor immunity. A monoclonal antibody targeting glycosylated PD-L1 (gPD-L1) blocks PD-L1/PD-1 interaction and promotes PD-L1 internalization and degradation. In addition to immune reactivation, drug-conjugated gPD-L1 antibody induces a potent cell-killing effect as well as a bystander-killing effect on adjacent cancer cells lacking PD-L1 expression without any detectable toxicity. Our work suggests targeting protein glycosylation as a potential strategy to enhance immune checkpoint therapy.

Screening For Factors Influencing Neurodegenerative Diseases

Screening for factors influencing neurodegenerative diseases, such as amyotrophic lateral sclerosis and frontotemporal dementia, shows the importance of modifiers of an important mechanism of those diseases: hexanucleotide-repeat expansions in the C9ORF72 gene that result in toxic dipeptide-repeat proteins that aggregate – abnormal protein aggregation being a key feature of many nervous system-related diseases. This may have implications for treatment.  Abstract:

Hexanucleotide-repeat expansions in the C9ORF72 gene are the most common cause of amyotrophic lateral sclerosis and frontotemporal dementia (c9ALS/FTD). The nucleotide-repeat expansions are translated into dipeptide-repeat (DPR) proteins, which are aggregation prone and may contribute to neurodegeneration. We used the CRISPR-Cas9 system to perform genome-wide gene-knockout screens for suppressors and enhancers of C9ORF72 DPR toxicity in human cells. We validated hits by performing secondary CRISPR-Cas9 screens in primary mouse neurons. We uncovered potent modifiers of DPR toxicity whose gene products function in nucleocytoplasmic transport, the endoplasmic reticulum (ER), proteasome, RNA-processing pathways, and chromatin modification. One modifier, TMX2, modulated the ER-stress signature elicited by C9ORF72 DPRs in neurons and improved survival of human induced motor neurons from patients with C9ORF72 ALS. Together, our results demonstrate the promise of CRISPR-Cas9 screens in defining mechanisms of neurodegenerative diseases.

Protein And Fat Free mass in Female Resistance Training

In a group of female athletes undergoing resistance training, a high protein diet improved fat free mass gain but was not required for gains in strength.  This is an interesting finding that may or may not be generally applicable to all resistance trainers.  It can make sense if one presumes maximal hypertrophy requires significant extra protein, but that the neural and muscular adaptions required for strength do not.  However, more study is required to determine how applicable this is for, e.g., the advance trainee, including men.  Abstract:

Aspiring female physique athletes are often encouraged to ingest relatively high levels of dietary protein in conjunction with their resistance-training programs. However, there is little to no research investigating higher vs. lower protein intakes in this population. This study examined the influence of a high vs. low protein diet in conjunction with an 8-week resistance training program in this population. Seventeen females (21.2±2.1 years; 165.1±5.1 cm; 61±6.1 kg) were randomly assigned to a high protein diet (HP: 2.5g/kg/day; n=8) or a low protein diet (LP: 0.9g/kg/day, n=9) and were assessed for body composition and maximal strength prior to and after the 8-week protein intake and exercise intervention. Fat-free mass (FFM) increased significantly more in the HP group as compared to the LP group (p=0.009), going from 47.1 ± 4.5kg to 49.2 ± 5.4kg (+2.1kg) and from 48.1 ± 2.7kg to 48.7 ± 2 (+0.6kg) in the HP and LP groups, respectively. Fat mass significantly decreased over time in the HP group (14.1 ± 3.6kg to 13.0 ± 3.3kg; p<0.01) but no change was observed in the LP group (13.2 ± 3.7kg to 12.5 ± 3.0kg). While maximal strength significantly increased in both groups, there were no differences in strength improvements between the two groups. In aspiring female physique athletes, a higher protein diet is superior to a lower protein diet in terms of increasing FFM in conjunction with a resistance training program.

Strains Of Misfolded Proteins And Alzheimer's Disease

Neurodegenerative diseases tend to involve tangled misfolded proteins, and for some diseases “strains” are already known.  Here we see that the same applies for amyloid and tau proteins in Alzheimer’s disease, a finding that can be helpful for targeted, personalized medicine.  Abstract:

Most neurodegenerative diseases are proteinopathies, which are characterized by the aggregation of misfolded proteins. Although many proteins have an intrinsic propensity to aggregate, particularly when cellular clearance systems start to fail in the context of ageing, only a few form fibrillar aggregates. In Alzheimer disease, the peptide amyloid-β (Aβ) and the protein tau aggregate to form plaques and tangles, respectively, which comprise the histopathological hallmarks of this disease. This Review discusses the complexity of Aβ biogenesis, trafficking, post-translational modifications and aggregation states. Tau and its various isoforms, which are subject to a vast array of post-translational modifications, are also explored. The methodological advances that revealed this complexity are described. Finally, the toxic effects of distinct species of tau and Aβ are discussed, as well as the concept of protein 'strains', and how this knowledge can facilitate the development of early disease biomarkers for stratifying patients and validating new therapies. By targeting distinct species of Aβ and tau for therapeutic intervention, the way might be paved for personalized medicine and more-targeted treatment strategies.

Athletic Protein Requirements While Dieting

To maintain skeletal muscle while losing weight, a significant increase in protein consumption over the RDA seems to be required.  Please note though that high protein intakes can be hard on the kidneys (among other things), depending on how high is "high" and for how long the intake is.  Therefore, it is prudent to have medical/nutritionist supervision if switching to a diet that is in large excess of normal protein requirements.  Abstract:

There exists a large body of scientific evidence to support protein intakes in excess of the recommended dietary allowance (RDA) (0.8g protein/kg/d) to promote the retention of skeletal muscle and loss of adipose tissue during dietary energy restriction. Diet-induced weight loss with as low as possible ratio of skeletal muscle to fat mass loss is a situation we refer to as high quality weight loss. We propose that high quality weight loss is often of importance to elite athletes in order to maintain their muscle (engine) and shed unwanted fat mass, potentially improving athletic performance. Current recommendations for protein intakes during weight loss in athletes are set at 1.6-2.4g protein/kg/d. However, the severity of the caloric deficit and type and intensity of training performed by the athlete will influence at what end of this range athletes choose to be at. Other considerations regarding protein intake that may help elite athletes achieve weight loss goals include the quality of protein consumed, and the timing and distribution of protein intake throughout the day. This review highlights the scientific evidence used to support protein recommendations for high quality weight loss and preservation of performance in athletes. Additionally, the current knowledge surrounding the use of protein supplements, branched chain amino acids (BCAA), β-Hydroxy β-Methylbutyrate (HMB), and other dietary supplements with weight loss claims will be discussed.

How Much Protein Can The Body Use In A Single Meal For Muscle-Building?

There is controversy about how much protein can be properly utilized by the body per meal for purposes of muscle building.  There is a school of thought that says that, essentially, anything over 20-25 grams per meal will be wasted; on the other hand, bodybuilding tradition advocated considerably higher per meal intakes (leading to much higher per day intakes compared to the typical recommendations).  A study examines the question and comes down on the side supporting the higher levels of protein intake; they write: “The preponderance of data indicate that while consumption of higher protein doses (> 20 g) results in greater AA oxidation, this is not the fate for all the additional ingested AAs as some are utilized for tissue-building purposes. Based on the current evidence, we conclude that to maximize anabolism one should consume protein at a target intake of 0.4 g/kg/meal across a minimum of four meals in order to reach a minimum of 1.6 g/kg/day. Using the upper daily intake of 2.2 g/kg/day reported in the literature spread out over the same four meals would necessitate a maximum of 0.55 g/kg/meal.”  Abstract:

Controversy exists about the maximum amount of protein that can be utilized for lean tissue-building purposes in a single meal for those involved in regimented resistance training. It has been proposed that muscle protein synthesis is maximized in young adults with an intake of ~ 20-25 g of a high-quality protein; anything above this amount is believed to be oxidized for energy or transaminated to form urea and other organic acids. However, these findings are specific to the provision of fast-digesting proteins without the addition of other macronutrients. Consumption of slower-acting protein sources, particularly when consumed in combination with other macronutrients, would delay absorption and thus conceivably enhance the utilization of the constituent amino acids. The purpose of this paper was twofold: 1) to objectively review the literature in an effort to determine an upper anabolic threshold for per-meal protein intake; 2) draw relevant conclusions based on the current data so as to elucidate guidelines for per-meal daily protein distribution to optimize lean tissue accretion. Both acute and long-term studies on the topic were evaluated and their findings placed into context with respect to per-meal utilization of protein and the associated implications to distribution of protein feedings across the course of a day. The preponderance of data indicate that while consumption of higher protein doses (> 20 g) results in greater AA oxidation, this is not the fate for all the additional ingested AAs as some are utilized for tissue-building purposes. Based on the current evidence, we conclude that to maximize anabolism one should consume protein at a target intake of 0.4 g/kg/meal across a minimum of four meals in order to reach a minimum of 1.6 g/kg/day. Using the upper daily intake of 2.2 g/kg/day reported in the literature spread out over the same four meals would necessitate a maximum of 0.55 g/kg/meal.

This conclusion is supported by this other study, which also advocates higher per meal protein intakes.

Please note that this advice – from these studies and not from this blog – deals with effects on muscle building and not overall health.  Whether or not additional protein intake is good for you is something that you need to determine in conjunction with your physician, nutritionist, etc.  For example, people with kidney problems or some digestive disorders probably should not be consuming this much protein, and then there is the issue of how much saturated fat is being consumed, if animal proteins are utilized.

So what is best for muscle building and what is best for overall health are not the same thing.

Protein Types And Muscle Building

By Adrem68 at Dutch Wikipedia - Transferred from nl.wikipedia to Commons., Public Domain, https://commons.wikimedia.org/w/index.php?curid=3224328

Aging individuals lose muscle mass for a variety of reasons, one of which is reduced muscle protein being synthesized after ingestion of dietary protein.  A study has shown that animal proteins are more anabolic (muscle building) than plant proteins.  However, as the authors seem to have social and political motivations here (e.g., environmental concerns), they state mechanism whereby plant-based proteins can be more effective for muscle building: ingestion of a greater amount of protein, combining plant proteins to get a better intake of amino acids (“the mixing plant foods for a complete protein profile,” I assume), leucine co-ingestion, and “prior exercise or n-3 fatty acid supplementation” can better sensitize muscle to the protein. Abstract:

The age-related loss of skeletal muscle mass and function is caused, at least in part, by a reduced muscle protein synthetic response to protein ingestion. The magnitude and duration of the postprandial muscle protein synthetic response to ingested protein is dependent on the quantity and quality of the protein consumed. This review characterises the anabolic properties of animal-derived and plant-based dietary protein sources in older adults. While approximately 60 % of dietary protein consumed worldwide is derived from plant sources, plant-based proteins generally exhibit lower digestibility, lower leucine content and deficiencies in certain essential amino acids such as lysine and methionine, which compromise the availability of a complete amino acid profile required for muscle protein synthesis. Based on currently available scientific evidence, animal-derived proteins may be considered more anabolic than plant-based protein sources. However, the production and consumption of animal-derived protein sources is associated with higher greenhouse gas emissions, while plant-based protein sources may be considered more environmentally sustainable. Theoretically, the lower anabolic capacity of plant-based proteins can be compensated for by ingesting a greater dose of protein or by combining various plant-based proteins to provide a more favourable amino acid profile. In addition, leucine co-ingestion can further augment the postprandial muscle protein synthetic response. Finally, prior exercise or n-3 fatty acid supplementation have been shown to sensitise skeletal muscle to the anabolic properties of dietary protein. Applying one or more of these strategies may support the maintenance of muscle mass with ageing when diets rich in plant-based protein are consumed.

Breakfast Protein: Egg Whites

New studies show that eating whole eggs, in moderation, may not be bad for the health of most people, and can actually have benefits. The yolk is enriched in vitamins and has protein, and I do occasionally eat whole eggs.

However, in order to get some breakfast protein without the fat and cholesterol of the yolk, I eat egg whites a couple of days per week. I buy the small cartons of pasteurized egg whites. Once opened, these cartons should be used within a week. These egg whites can be microwaved, and I like to prepare mine in advance. I put ½-2/3 of one small carton into a microwave-safe bowl, and cover with plastic wrap. Microwave on high one to one-and-a-half minutes (1:00-1:30), stir with a spoon, repeat, stir again with a clean spoon, repeat as required so the whole bit is completely cooked, without liquid even at the bottom of the bowl. Depending upon how much I cook at one time, it takes between 2:30-3:30 minutes. The cooking time, of course, also depends on the power of the microwave and the dimensions and shape of the bowl.

Cooked egg whites can last several days in the fridge. I also freeze batches. True, they may be a bit rubbery once thawed out (and I thaw them in the microwave on top of a paper towel on a microwave-safe dish; the paper towel is to soak up any excess water from the freeze-thaw), but they are edible and the difference in taste and texture to non-frozen is slight.

One meal idea is to warm the cooked egg whites and melt a slice of non-fat cheese on top. Then put the egg white-cheese mixture inside of a toasted 100% whole wheat bagel with a bit of Smart Balance and some red pepper hot flakes (or other seasoning). This is an excellent high-protein, law-fat, high fiber breakfast with added calcium.

One note: egg whites are enriched in avidin, which binds biotin. Frequent consumption of raw egg whites can cause a serious biotin deficiency. Cooking inactivates most of the avidin in egg whites, but not completely; therefore, consumption of a large amount of egg whites on a frequent basis may cause a biotin deficiency. Actually, egg yolks are an excellent source of biotin, another reason why whole eggs in moderation can be a good choice.

Plain non-fat Greek yogurt is another way of obtaining breakfast protein. Those who are lactose intolerant can often eat moderate amounts of yogurt, especially yogurt with live cultures that help break down lactose.