The Female(?) Athlete Triad - Part III/III: Road to Recovery! Step #1 = "Increase Your Energy Intake"! Plus: Learn How to Calculate Your Resting Energy Expenditure (BMR)

You don't have to eat Burgers and French fries all day, but it's almost certain that you got to eat MORE than before. In this installment we will thus take a look on how much you'd minimally to function in your regular everyday life.

I have to admit I did underestimate the workload that would be associated with the SuppVersity Female(?) Athlete Triad Series. When I wrote the first part of this series, I originally did not even plan to have a second, let alone third part. Now, I've reached Part III and have to realize that the simple question "how much do I have to eat" can become pretty hairy. Not the least, because I personally have never been an advocate of meticulous calorie counting and yet cannot ignore the fact that I have to give you something you can start from... to cut a long story short, also to avoid falling victim to the aforementioned "bloggers triad", I will tackle the rest of this series, the "Road to Recovery" as I called it in as many steps as it will take: No renumbering just Step #1, Step #3, Step #3, ...

In view of the fact that each of those steps should contain at least one thing you can actually do, we will start out right with the single most important change you will have to make in order to escape the self-perpetuation vicious circle I've been outlining in the last installment of this series.

Step 1: Increase your energy intake! But how much do you need?

Figure 1: Dose-dependent effects of restricted energy availability on LH pulse amplitude (squares, top) and frequency (triangles, bottom) in subgroups of women with luteal phases of exactly 11 days and >11days.  Effects are relative to values at 45 kcal/lean body mass (Loucks. 2003)

If you take a look a the way the luteinizing hormone secretion becomes impaired, when your energy intake goes below a critical threshold of roughly 30kcal/kg (for men you will see propably see your T-levels plummet if you go below this level - diet or not!), it should be obvious that your first step towards recovery is to increase your basal energy intake, i.e. the amount of energy you consume irrespective of your daily energy expenditure, above this critical threshold.

For a 25-year old woman with a body fat percentage of 20% and a total body weight of 65kg this would imply that your daily energy intake must never be lower than 0.8 x 65kg x 30kcal/kg = 1560kcal - even when you are dieting.

Despite being based on empirical evidence, going solely by LH abnormalities is probably not the best way to estimate your energy requirements. Therefore, I have picked two practical alternatives for you to chose from:

• The standard equation to calculate the basal metabolic rate independent of your daily activity levels, i.e. the Harris-Benedict equation reads (the values are in kg, cm and years, for weight, height and age, respectively)
• REE (women) = 655.1 + 9.5663 x weight in kg + 1.85 x height - 4.676 x age
• REE (men) 66.5 + 13.75 x weight  + 5.003 x height - 6.775 x age

• 

  Active (wo-)men need more than their REE (img sheknows.ca)

  Multiplied with the "correct" Acitivity Level Factors these REE values will also yield an estimation of your overall daily energy expenditure which is 1.53x, 1.76x and 2.25x higher than your REE depending on whether you are sedentary or lightly active (1.53x), active or moderately active (1.76x) or vigorously active (2.25x), with the latter being the category approx. 90% of those who are trapped in the athlete triad still belong to.
• Probably more accurate since developed and tested with an athletic population, but reliant on way more information would be a recently proposed equation by Oshima et al., which reads
• REE (men & women) = 2.3 x bone mineral weight + 4.5 x adipose tissue weight + 13 x skeletal muscle weight + 54 x rest weight*
  *(brain, liver, kidney, glands, skin, etc.)
• It is easy to see that this equation has been developed to be used in professional studies. After all, the majority of people won't even know that there is a profound difference between both your fat mass and your total adipose tissue mass, as well as your "lean mass" and the amount of skeletal muscle tissue you are effectively carrying around.

* * *

While the calculation of your resting energy expenditure with the Harris-Benedict equation should actually be pretty straight forward and yields

Daily REE (Harris-Bendict) = 655.1kcal + 9.5663kcal/kg x 65 kg
+ 1.85kcal/cm x 170cm - 4.676kcal/year x 25 years = 1474.51kcal

the same cannot be said of the more sophisticated equation Oshima et al. proposed. Not because it was more complicated to plug the figures into a calculator, but rather because you are unlikely to have the respective data handy.

How to use the Oshima equation without DXA data - An example

Since this is at least in my experience the parameter most of you will be missing, I base the following example calculation on the assumption that we don't have the quantitative data on Mrs Jane Average's bone mineral density and are thus not able to estimate the corresponding bone mass (in kg) by multiplying the bone mineral density (in g) by x 1.85 / 1000.

Figure 2: The individual contribution of the body compartments (based on Oashima. 2011 & Taguchi 2011) in the Oshima equation relative to total body weight in 57 male and 93 female athletes can serve as a basis to estimate your resting energy expenditure. The text provides an example how this is done for a 25y-old, 170cm, 65kg woman with 20% body fat. The same can be done for men & women from other "weight classes", the values are yet probably not representative of live-long sedentary individuals

For Jane Average, the athletic woman from our previous example, who had a total body weight of 65kg and a body fat percentage of 20%m we can still estimate all the parameter we need by extrapolating values from the data in figure 2 (don't tell me that's not accurate, you will be surprised ;-):

Do not count each salad leaf! As mentioned in the introduction, already, I have never been a fan of calorie counting. Part of the problem of the athlete triad is however that once you are in it, you have no baseline you could tweak by following my usual advise of logging your food intake for 1-2 weeks, taking stock and going from there. Likewise you can (for the reasons I explained in the last installment) not go by your appetite / hunger, simply because you have long "starved it away". If you really want to return to normalcy, however, you must not start to count the energetic value of each and every salad leaf, tomato, piece of broccoli or single rice corn you put into your. Therefore, the things you will count are ...

• meats, eggs, fish, dairy, etc.
• rice, (sweet) potatoes, oats, pasta, bread, etc.
• coconut oil, olive oil, butter, ghee, sauces, etc.
• any form of treat / fast and convenient food or caloric beverage
• food supplements, e.g. protein shakes or bars

You will also count pieces of fruits and veggies with a caloric value similar to carrots, but whenever you catch yourself cutting off half of the asparagus spear you were just about to eat, eat at least another two + buttery Sauce Hollandaise on top ;-)

• assuming that the body height of our woman is 1,70cm, she would have a BMI of 22.5 kg/m² and therefore fall into the middle category in figure 2
  
• accordingly her bone mineral weight would be ~7% of her body weight, which allows us to estimate her total bone mineral weight to be 4.55kg
• her total fat mass, which is ~85% of the total adipose tissue weight would be 20% of her body weight, i.e. 13kg; we need to multiply that by 1.18 in order to accommodate for the non-fat part of the adipose tissue and get a total adipose tissue mass of 15.3kg

Since the weight of the "other organs" (including brain, liver, kidney, skin, etc.) is subject to lower inter-individual differences, than the exact amount of skeletal muscle, we will use the purple 30% "rest / organ mass" value from figure 2 (remember with a BMI of 22.5 our exemplary woman falls into the middle category) instead of simply relying on the  common yet incorrect assumption that the skeletal muscle mass was was more or less identical to the difference of total body and fat mass:

• to determine the weight of the metabolically highly active organs (compare the coefficients to those of the "purported fat burner" skeletal muscle - at rest, brain, liver, kidney, but also ovaries & co consume 4x more energy than muscle!) in the Oshima equation we  multiply the total body weight with0.3 (=30%) and get a a "rest weight" of 19.5kg
• eventually we determine the skeletal muscle weight by simply subtracting all the values we have from the total body weight - viola, our exemplary woman has a skeletal muscle weight of 25.65kg

All that's left to do now, is to plug those values into the Oshima equation, which will then look like this:

Daily REE (Oshima) = 2.3kcal/kg x 4.55kg + 4.5kcal/kg x 15.3kg
+ 13kcal/kg x 25.65 kg + 54kcal/kg x 19.5kg = 1465.77kcal

So, assuming that I did not hit the wrong buttons on my calculator, this result is actually almost identical (8.74kcal/day) to the estimation the Harris-Benedict equation yielded. This in turn, goes to show you that within the "normal zone", into which Mrs. Jane Average certainly would fall, simple standard equations such as the often criticized, yet still widely used Harris-Benedict equation appear to be pretty accurate. At least, when we are talking about the minimal requirements of someone who's not doing much more than walk from the bed, to the fridge, to the car, to the table in his office, back to the car and ... you know what the average white-color worker does these days.

Extraordinary individuals have extraordinary energy requirements - and you are extraordinary!

Fortunately, you are none of those office "triseathletes" whose athletic triad consists of exhaustive in your office chair idling, extreme stressed in the car sitting and lazy on the couch lying... right? I thought so! And this is why there is no way that the ~1,500kcal will suffice to break out of the vicious circle of a real athlete's triad. 

On the contrary, it is however "as sure as eggs is eggs" that falling short of those minimal energy requirements is the single best recipe to fall victim to the very same triad.

Resting metabolic rate and real-life energy requirements

If you take another look at figure 1, the corresponding LH-based energy intake rule of thumb, I derived from the data by Loucks et al., as well as the coefficients (the factors in front of the parameters) in the Oshima equation, it should actually be obvious that those basal energy requirements are more or less "hard-wired" into our hypothalamic energy control system. With 54 out of 74kcal/kg body weight (73%) being used simply for the maintenance of organ functions, alone (!), there is not much room to conserve energy other than eating up the organs, the bones and the skeletal muscle and of course shutting down such superfluous organs as the ovaries or testes, and... hold on, aren't that all the symptoms of the athlete's triad?

Figure 3: Mean, median and minimal energy intake (in kcal/kg) in eumenorrheoic vs. amenorrheoic female athletes (data calculated based on an overview in Manore. 2002)

Against that background it is no wonder that my statistical makeover of the stats from a list of studies that was included in a 2002 paper by Manore, already suggests that the 1,500kcal are in fact an absolute minimum for the real light-weights among female athletes. Only in one of the 15 studies with datasets from 138 women on which the values in figure 3 are based, were the ~30kcal/kg body weight sufficient to prevent onset of amenorrhea. And when I am telling you that this group of female athletes also happened to be the group who consumed the highest amount of carbohydrates relative to their overall calorie intake per kg of body weight, I am actually already touching on the topic of the next installment, in which we are going to take a look on how you should distribute your overall energy intake across the macronutrient spectrum.
 
A pros pos, while you are waiting for the next installment of this series you should stop counting asparagus spears, calculate your resting metabolic rate and see where you are standing, in terms of your current caloric intake! And though I personally doubt both the quantitative validity of the activity level factors Harris and Benedict provide, you should not forget that chances are slim if not non-existent, that you will recover, if you don't aim for a 1.76x higher energy intake than your RMR calculations would prescribe on workout days.

References:

• Harris JA, Benedict FG. A biometric study of basal metabolism in man. Publ no 279. Washington, DC: Carnegie Institution, 1919.
• Loucks AB, Thuma JR. LH pulsatility is disrupted at a threshold of energy availability in regularly menstruating women. J. Clin. Endocrinol. Metab. 2003; 88: 297–311. 
• Manore MM. Dietary recommendations and athletic menstrual dysfunction. Sports Med. 2002;32(14):887-901.
• Oshima S, Miyauchi S, Kawano H, Ishijima T, Asaka M, Taguchi M, Torii S, Higuchi M. Fat-free mass can be utilized to assess resting energy expenditure for male athletes of different body size. J Nutr Sci Vitaminol (Tokyo). 2011;57(6):394-400.
• Taguchi M, Ishikawa-Takata K, Tatsuta W, Katsuragi C, Usui C, Sakamoto S, Higuchi M. Resting energy expenditure can be assessed by fat-free mass in female athletes regardless of body size. J Nutr Sci Vitaminol (Tokyo). 2011;57(1):22-9.

Do Chronic Energy Deficits Make Athletes Fat? The Longer & More Severe You Starve, the Fatter You Are. Irrespective of What the Calories-in-VS-Calories-Out Formula May Say

This is not an "anti-gymanstics" or "anti-runners" article, this is an anti-ruin-your-life-post for the average female and male gymrat.

Maybe you've read about the results Deutz, Bernardot, Martin and Cody published in their 1999 paper on the "Relationship between energy deficits and body composition in elite female gymnasts and runners"... in fact, it may be possible that I already mentioned it in the "Athletes Triad Series" (read more), but even if I did, the fact that I get messages like "I eat 1,100kcal/day and still gain, not lose fat" or "my girlfriend eats 900kcal/day and maintains that this is normal", tells me it does not matter if I mention one or two of the figures the authors compiled in this unfortunately highly "under-cited" paper (only 72 citations are referencing this article) twice.

If that makes just one of the victims of their own ambition rethink what he or she is doing, it was well worth... wouldn't you agree?

Can the elite be wrong?

Usually you would assume that elite athletes are doing everything right, they are the epitome of our modern understanding of "health". As a SuppVersity reader you are yet well aware that there is a disconnect between optimal health and performance and with the latter being in part dependent on having a certain look as it is the case for bodybuilding, figure competitions and the like this disconnect can be so huge that being successful may eventually require a non-genetically gifted athlete to sacrifice his or her health on the altar of a misinterpretation of "physical culture".

That being said there is a way more traditional and, contrary to bodybuilding, officially Olympic sport where similar rules apply: Gymnastics! Especially among the female competitors the paradigm still is - the thinner the better. And to make things even worse, in this case "thin" actually means "thin" as in "being able to hide behind a straw". Now, this is obviously not the case in any of the aforementioned disciplines and yet they claim way more victims of life-long dieting than those sports, where "being thin" is actually part of the game - and what's almost sarcastic, the tortures some professional and many hobby athletes subject themselves to are not even rewarded.

You will have to take the following figures with two grains of skepticism! One for the scientifically established bias due to under-reporting in female gymnasts (Jonnalagadda. 2000), and the other one for the discrepancy between factual and calculated energy expenditures, which is, due to the negative feedback chronic dieting exerts on the total energy expenditure, much narrower than the formulas suggest. And another thing, remember that we are talking about body-fat % not total body fat masses here!

Against that background you will probably not be surprised to hear that the vast majority of the elate female artistic (N=32) and rhythmic (N=11) gymnasts in the study at hand is consuming 1,002kcal less than they would actually need to satisfy their caloric demands.

Figure 1: Comparison of within-day energy balance in the four groups of elite athletes (left); largest energy deficit per hour and average 24h energy deficit in all athletes, gymnasts and runners (Deutz. 2000).

If you take a closer look at the data in figure 1 you will yet realize that the average medium- and long-distance runner is not much better off. Now, whether the latter is a necessary prerequisite to make it to the top or simply a result of being unable (for physical or psychological reasons) to compensate for the training induced increase in energy expenditure, is beyond the scope of this post and essentially irrelevant to the statistically highly relevant acorrelation between between energy balance and body fatness, I've plotted for you in figure 2.

Figure 2: Relationships (Pearson correlations) between energy balance factors and body fat percentage in all athletes, gymnasts, and runners (Deutz. 2000)

I hope that these results do not come as a surprise for the vast majority of those for whom this is not the first visit to the SuppVersity. After all, I have been trying my very best for years (hard to believe I am doing this "chronically" ;-) to scare you away from the chronic and towards the cyclic calorie reduction as a means to cut body fat and maintain muscle mass (note: with the relatively small study size not all effects reached statistical significance; for the parameters pertaining to the "energy out vs. energy in"-calculations the average dieter is so fond of, this was yet particularly noteworthy).

In athletes chronic "dieting" results in an increase in body fat percentage

The message is simple and so is the underlying mechanism. The chronic provision of an insufficient amount of energy leads to a metabolic downregulation that goes hand in hand with an increased disposition to store and a decreased disposition to let go of body fat.

Another note: This is not an anti-intermittent fasting article either. If you do IF to cut weight you will have an overall negative energy balance, just like on every other diet, but if you are doing it for life (for whatever reason), you should be meeting your daily energy demands. This means you would have a much higher energy surplus on the other hours - in essence the data simply don't apply to someone who is doing intermittent fasting on a maintenance diet.

The concomitant exercise induced physical stress lulls your body to believe that you are amidst a starvation period, where building muscle and/or maintaining more muscle than is absolutely necessary to sustain the regular exercise routines is a no go and each and every energy unit that that is not necessary to keep you from passing out will get stored to cover those hours with a per hour deficit of 750kcal (which is the average maximal deficit per hour in the rhythmic gymnast group).

---

Bottom line: Don't get fooled by the "Don't worry. That's not you, starve yourself! It's good for you - don't you feel it?" the little gal or guy in your shoulder is now whispering into your ear. The rule "chronic starvation = increase in body fat percentage" applies to male and female athletes, gymnasts, runners, sprinters, cyclists, fitness junkies, bodybuilders, footballers, ... and across a wide range of energy deficits.

You don't have to eat burgers and French fries all day, to meet your energy requirements. Living on chicken breast & broccoli for the rest of your life is neither necessary nor conducive to your goals, and that's even true for such profane goals as "staying lean"! And by the way - how much do you need (learn more)?

So say good buy to the little guy with the hunger high and use your brains and acknowledge to yourself: "I am a junky. A starvation junky!"  You are not? Well then check this out:

Addiction is a persistent, compulsive dependence on a behavior or substance. [...] Addiction has been extended [...] to include mood-altering behaviors or activities." (Livingston. 2008; my emphases)

And the main criteria for being addicted are a loss of willpower, fear of harmful consequences, an unmanageable lifestyle, tolerance or escalation of use and withdrawal symptoms upon quitting. Well if all that is not you and you. Stop working out like mad and return to eating normal without going crazy whenever you feel satiated, now!

References:

• Deutz RC, Benardot D, Martin DE, Cody MM. Relationship between energy deficits and body composition in elite female gymnasts and runners. Med Sci Sports Exerc. 2000 Mar;32(3):659-68. 
• Jonnalagadda SS, Benardot D, Dill MN. Assessment of under-reporting of energy intake by elite female gymnast. Int J Sport Nutr Exerc Metab. 2000 Sep;10(3):315-25.
• Livingstone, C. "addiction." Dictionary of Sport and Exercise Science and Medicine. 2008. Elsevier Limited 14 Jul. 2013 http://medical-dictionary.thefreedictionary.com/addiction

Protein Intake & Muscle Catabolism: Fasting Gnaws on Your Muscle Tissue and Abundance Causes Wastefulness

How much of the protein you can eat and how much of it you need two keep the status quo are very different questions.

Don't worry, this article is not about the notorious "Anabolic Barndoor" or the purported magic of "nutrient timing" and post.workout supplements. The thing I want to discuss in today's SuppVersity article is of a more general nature and revolves around the upregulation of the ubiquinase enzymes and consequent proteolysis (=catabolims) of skeletal muscle tissue ... or if you want to use my buddy Carl Lanore's term: "The loss of metabolic currency" we all know you better avoid at all costs, if you care about aging healthily. 

You can learn more about protein intake at the SuppVersity

Are You Protein Wheysting?

Cod protein for recovery

Protein requ. of athletes

High EAA protein for fat loss

Fast vs. slow protein

Too much ado about protein?

What we are going to deal with today is protein breakdown, or the purported general anticatabolic effect of high protein diets. To this ends, we will be taking a closer look at the ubiquitin proteasome system (UPS) response to constant energy deficits (ED) at varied dietary protein intakes before and after the consumption of a high protein meal replacement. An issue, by the way, that was also addressed in a paper that has been published a couple of days ago in the peer-reviewed scientific journal FASEB (Carbone. 2013).

No, this is not a deja vue! You've actually read about the same experiment, yet a different portion of the results back in June, in one of my previous articles on optimal protein intake / supplementation | read more 

In said paper by scientists from the School of Health Sciences at the Eastern Michigan University, the Nutrition Division at the U.S. Army Research Institute of Environmental Medicine, the Human Nutrition Research Center that's located at the U.S. Department of Agriculture, and the School of Medicine and Health Sciences at the University of North Dakota thirty-nine young, fit and healthy adult volunteers, who were caged in a metabolic ward, were randomized to one out of three groups with different baseline protein intakes:

• 0.8g/kg body weight of protein (RDA)
• 1.6g/kg body weight (2 -RDA), or 
• 2.4g/kg body weight (3 -RDA)

The participants, 32 men and 7 women, had to be between the ages of 18 and 42 yr and of stable weight ( 2 kg for a period of 2 mo), to have a body mass index (BMI) between 22 and 29 kg/m²,
and to be physically fit [peak oxygen intake (Vo2peak) 40–60 ml/(kg ·min)].

The subjects followed the prescribed dietary protocol for a whole month (31 days), went into a tightly controlled 10-day weight maintenance phase and started fasting for 21 days, immediately thereafter (Note: To keep the protein intake stable, the dietitians who planned and prepared the meals for all study participants had to prepare meals with a significantly higher relative protein content),

In this study: 30% energy restriction +10% physical activity = "fasting"

Just to avoid any confusions: The above, i.e. a 30% reduction in energy intake and a 10% increase in physical activity, is what John W. Carbone and his colleagues talk about, when they use the word "fasting". It does not mean that the subjects have been sitting in one of those tents, where you can actually measure the energy expenditure for 21-days eating nothing, but their finger and toe nails.

An important note on the accuracy of calculated: While Carbone et al. state that their -30% intake, +10% expenditure protocol will produce an energy deficit of 40%, I'd hope that you as seasoned SuppVersity students see through the futility of calculations like these and let go off figures that signify a degree of exactness that's simply not there.

In view of the fact that the term "fast" is contemporarily used to designate "diets" that are really low in energy (up to ZERO calories, intermittently), I suspect I should also mention that I personally would call the last 21 days of the study the "diet" not "fasting" phase.I mean, 30% reduced energy intake and +10% physical activity? We all know that the health and physique 90% of our fellow men and women would benefit from this regimen.

Muscle biopsies and enzyme expressions

The scientists took muscle biopsies before (fasted) and 2h after (fed) the ingestion of "a commercial nutrition supplement (Boost; Nestlé HealthCare Nutrition, Florham Park, NJ, USA)" with a total energy content of 480 kcal and 20 g of protein to assess the degree of intracellular proteolysis on day 10, i.e. right before the "fast", and day 31, i.e. right after the "fast", of which Carbone et al. write that it was based on individualized menus that were administered under supervision, to ensure compliance.

"To maintain fitness, the volunteers performed resistance type physical activity 3 d/wk, and daily endurance-type exercise, at levels comparable to those they had reported in their prestudy activity logs. To minimize the potential that an unaccustomed training stimulus would influence skeletal muscle outcomes and to ensure accuracy, research personnel closely controlled and monitored the intensity and volume of physical activity. For resistance-type exercise, the volunteers performed 1 single-joint movement per major muscle group (3 sets of 15 repetitions), using workloads determined during the prestudy period. The intensity of the endurance-type activity (40 – 60% VO2peak) was based on prestudy measurements, and verified by indirect calorimetry (ParvoMedics) and the corresponding heart rate during familiarization trials conducted before the study, and by the heart rate reserve-method throughout the interventio." (Carbone. 2013)

The 10% increase in physical activity was achieved by an increase in the length of the daily endurance training sessions that would accommodate for the corresponding increase in energy expenditure

Figure 1: Changes in lean body mass and fat mass (kg) that occured during the 21-days on 40% energy restricted diets with varying amounts of dietary protein in it (based on Pasiakos. 2013)

As you can see in Figure 1, which is based on results the researchers presented in a previous publication that was likewise discussed, here at the SuppVersity, this intervention was not without consequences on the body and fat mass of the study participants who lost on average 3.2 ± 0.2 kg body mass, but at very different lean:fat-mass ratio (learn more).

What's the more important "-bolism": Cata- or ana-bolism?

In contrast to their previous paper that focused exclusively on the increase in muscle protein synthesis, this "follow up"* discards the influx of dietary protein into the muscle of the subjects and focuses on the proteolytic enzymatic response to the diet  (*I assume both were filed at the same time, but the one in FASEB was published ahead of print, while the one at hand did not).

Figure 2: Enzymatic activities for 26S 1(A), 26S 2(B), 26S 5(C), and caspase-3 (D). Open bars, weight maintenance; solid bars, energy restriction.

Put differently, instead of asking the likewise important question: "What's more anabolic?" that was already answered in the paper by Pasiakos et al. (read more). Carbone et al. focus on the similarly or even more important question: "What's more catabolic?" - with a quite intriguing outcome, if I may say.

I mean, you would expect that the activity of the catabolic enzymes would vary depending on the protein content of the diets, wouldn't you? No? Well, maybe you did expect that the response to the 20g protein shake the subjects consumed would have an effect on their expression (black bars in Figure 2)?

You didn't? Tthat's awesome, you must be a genius, 'cause nothing of that actually happened. In other words, the expression of proteolytic enzymes did not in any way or form depend on the total amount of protein, the healthy young subjects in the study at hand consumed on a daily basis - once, twice or thrice the RDA of 0.8g/kg body weight.

Take home message #1 -- Your daily total protein intake has no effect on the expression of catabolic enzymes in your musculature. Even your total energy intake has little effect on the expression of catabolic enzymes in your musculature.

And if we are honest, most of us would probably also have expected a much more pronounced difference in these markers of muscle catabolism, when comparing the weight maintenance to the fasting phase (white vs. black bars) - a difference that existed for some yet not all of the ubiquinase enzymes, but was statistically significant for none of them.

Figure 3: mRNA expression of the Ub ligases MuRF1, atrogin-1 and TNF-alpha (Carbone. 2013)

And just in case you find all that not yet surprising enough, I'd suggest you take a parting look at the Murf-1 and atrogin-1 expression in Figure 3 -- what do you see? Correct, Murf-1 and atrogin-1 are the most prominent members of muscle-specific proteases that are highly expressed during muscle atrophy (Gomes. 2001; Witt. 2005); and you are also correct, if you are now scratching your head thinking:

"But how come that both are increased with higher protein intakes?"

Actually you know the answer already. It's after all not just take home message #2 of today's SuppVersity article, but has been addressed in many previous articles on total protein intake and the effects of protein supplementation here at the SuppVersity, as well.

Take home message #2 -- The more protein you eat the more wasteful your body will be (note: this does not mean that the net protein retention does not increase, but it means that you will see diminishing at intakes of thrice the RDA even non-existent returns; cf. "Are you Protein Wheysting?")

So what's left do discuss then? Ah, right, aside from the proteolytic enzymes, the scientists also tested for changes in the expression of TNF-alpha & co and observed that the expression of TNF- mRNA and activation of NF- B1 increased as protein intake exceeded the RDA.

This increase in TNF-alpha and NF-B1 may at first surprise you - TNF [tumor necrosis factor] and consequent NF- B activation are, after all, generally associated with increased muscle proteolysis. If you look back at "take home message #2", however, you'll realize that this, i.e. an increase in muscle proteolysis is exactly what's going on, in the 2x and 3x RDA groups. It is thus also logical that this increase in tumor necrosis factor occurs only in the fed state - a state, when dietary protein is abundantly available.

So what's to be learned on the practical side of things, then? In view of the results of the study at hand, it appears as if we may in fact have overrated the influence of the loss of skeletal muscle protein, i.e. proteolysis, in the past. Compared to the amplitude, or differences between ups and downs of protein synthesis the activity of the proteolytic enzymes is (a) very constant and does (b) depend inversely, but non-linearly on the total amount of protein you eat.

Remember the recent article about the myostatin reducing and thus potentially muscle building effects of low protein diets? | read more

Practically speaking this means that there is a relatively low threshold beyond which the "loss" of protein (=protein not being incorporated into the muscle tissue) keeps increasing, while the storage of protein stagnates. A hypothesis that stands in line with the results of experiments that investigated the differential effects of bolus (=all at once) vs. staggered (=in 4x20g or 8x10g) ingestion of protein supplements (see "Slow or Fast, Bolus or Pulse? Protein Synthetic Response is Identical!" | read more) and the revelation that protein fasting can decrease the expression of myostatin and thus ramp up the capacity for and efficacy of muscular protein storage (see "36% Decrease In Myostatin, With Low Protein (0.1g/kg BW) Diet" | read more).

References:

• Carbone, J. W., Margolis, L. M., McClung, J. P., Cao, J. J., Murphy, N. E., Sauter, E. R., ... & Pasiakos, S. M. (2013). Effects of energy deficit, dietary protein, and feeding on intracellular regulators of skeletal muscle proteolysis. The FASEB Journal, 27(12), 5104-5111.
• Gomes, M. D., Lecker, S. H., Jagoe, R. T., Navon, A., & Goldberg, A. L. (2001). Atrogin-1, a muscle-specific F-box protein highly expressed during muscle atrophy. Proceedings of the National Academy of Sciences, 98(25), 14440-14445.
• Pasiakos SM, Cao JJ, Margolis LM, Sauter ER, Whigham LD, McClung JP, Rood JC, Carbone JW, Combs GF Jr, Young AJ. Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial. FASEB J. 2013 Jun 5. [Epub ahead of print].
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