How Much Protein Do You Really Need To Increase Muscle Mass & Lose Fat & Optimize Performance *
One of the most controversial aspects of nutrition is the issue of protein intake- namely how much protein do you really need intake for increasing strength, lean muscle mass and or improving athletic performance while minimizing body fat. The US and Canadian Recommended Daily Allowances (RDA) call for a protein intake of 0.8 grams of protein per kilogram of body mass for adults.  What many would term a paltry amount as it works out to about two chicken breasts a day for a 180lb man. Many serious weight training athletes consume this much in one sitting and most in the trenches from coaches to trainers would argue that such numbers don’t take into consideration increased protein demands brought on by intensive resistance exercise. While the argument that an athlete focused on building muscle would have higher protein needs than a sedentary individual sounds almost self-evident- the science to support this claim isn’t as clear cut as it may seem. In fact, it’s far more complicated than most would care to admit.
In this article we’ll take a critical look at the science behind some of the main questions regarding protein intake- Do athletes need more protein than sedentary individuals? How much protein should you eat to maximize muscle and strength gains? Can you eat too much protein? And most importantly- are there negative health consequences from eating a protein diet several magnitudes higher than the RDA? My intention is that this post provides you with a thoughtful and comprehensive overview of the current data regarding protein intake requirements in addition to highlighting some real world examples that do appear to contradict common expectations. In the end I hope it serves as a tool to help you make informed decisions regarding your own dietary practices. It’s quite a read, but it’s worth it!
What Is Dietary Protein?
Before we delve into the intricacies of protein requirements and intake a definition of dietary protein is most certainly in order. Proteins are one of the three macronutrients that our body needs for optimal health along with carbohydrates and fats and they serve as building blocks for our body on a cellular level. When you eat a food that is high in protein, (egg whites for example), what you are actually consuming are chains of amino acids called polypeptides. There are a total of twenty amino acids out of which nine are known as essential amino acids. They are essential because they can only be obtained from the foods we eat as our bodies cannot produce them from other amino acids and proteins. If we don’t get them from our diet our body will attempt to get them by breaking down existing muscle and other tissues- a process called catabolism. Pretty much the opposite of what you would want to happen if you are trying to increase strength and muscle mass. The nine essential amino acids are leucine (an important one with regards to exercise as we will see later on in the article), isoleucine, lysine, theonine, tryptophan, methionine, histidine, valine and phenylalanine. Animal protein sources such as meat, fish, eggs and dairy contain all nine essential amino acids whereas plant protein sources such as beans, peas, nuts, grains and seeds don’t contain all nine. However by eating a varied diet of different plant protein sources you will always get all nine essential amino acids- even if you don’t eat them in the same meal. 
Protein Requirements- Understanding The RDA & AMDR
The first step in understanding the discrepancies between protein intake standards established by the Institute of Science and what most in the fitness field consider optimal is an understanding of what the Rrecommended Daily Allowance (RDA) is and what it is not. Information complied for the RDA is meant to cover the daily dietary protein needs of 97.5% of healthy adult men and women over the age of 19. It is calculated with the idea of preventing deficiencies and maintaining public health and not as a guide for optimal performance for athletes and those engaged in intense resistance type exercise. Such individuals do not represent the general population and it would be absurd to set a standard that caters to a very small minority. What was established however was an Acceptable Macronutrients Distribution Range (AMDR) which expresses a more flexible range of intakes to cater for those who may have protein requirements above that of the RDA. Expressed as a percentage of total energy intake the protein AMDR calls for an intake of 10% to 35% of total calories. While these figures give a bit more leeway to allow for higher protein intakes there is yet no clear evidence that this is an actual requirement for athletes.
Possible Additional Protein Intake Requirements For Athletes Due to Exercise *
Resistance exercise such as weight training has a significant effect in the promotion of muscle growth. A process which can be defined as an adaptive response whereby the body increases net protein accumulation in the form of skeletal muscle. (See my article on how muscles get bigger and stronger for a detailed overview). This response can only occur if muscle protein synthesis (an anabolic state where muscle proteins are built up) exceeds muscle protein breakdown (a catabolic state where muscle proteins are broken down). An athlete or individual involved in muscle building resistance type training should thus be very concerned about their protein intake to ensure that post exercise protein synthesis occurs to the greater extent possible. A protein intake that would have to compensate for the following demands created by intensive exercise:
1. To repair replace and remodel damaged proteins within muscles, bones, tendons and ligaments.
2. To maintain optimal function of all metabolic pathways that use amino acids
3. To support incremental increases in muscle mass.
4. To support an optimally functioning immune system under the stressful demands of intense activity.
5. To support optimal rate of plasma protein production.
6. To support other metabolic processes that require amino acids at rates higher than that of non-athletes.
How Protein Intake Affects Muscle Growth *
We have established that resistance training of sufficient intensity improves muscle protein balance and promotes an anabolic state but in the absence of an adequate dietary protein, there is the possibility of a catabolic effect. A large body of evidence shows that the provision of essential amino acids supports increased rates of protein synthesis and positive protein balance when ingested after resistance exercise [6,7,8,9,10] and to a lesser degree after endurance exercises.[11,12] Urea is a waste product created from protein metabolism in the liver and by monitoring urea excretion scientists can get a rough idea as to how much dietary protein is actually used by the body and how much is simply excreted. In all of the aforementioned studies there was no increase in post exercise urea levels. This suggests that the protein ingested after exercise was fully and efficiently utilized for protein synthesis and other metabolic processes requiring amino acids.[3,6,7,8,9,10] So we know that muscle protein metabolism after resistance type exercise depends on the availability of essential amino acids. However what isn’t clear from these studies is exactly how much of the protein consumed went towards the actual creation of new muscle. Thus the question remains unanswered as to exactly how much extra protein is really needed to support gains in muscle mass.
Protein Requirements For Protein Synthesis After Resistance Exercise *
While we may not have a precise directive telling us how much protein is needed to support increases in muscle mass, we do have the benefit of some possibly relevant findings. The first is that studies have demonstrated that protein synthesis is elevated (and amino acid losses are curtailed) for up to 48 hours after a bout of resistance exercise. We also know from a now landmark study that an oral dose of 10 grams of essential amino acids maximally stimulates muscle protein synthesis in non-exercising individuals regardless of age. Taking these factors into consideration we have at least a starting point from which to access possible protein needs. If we look at the essential amino acid composition of high quality protein sources such as meats and egg whites, 10 grams of essential amino acids works out to be just about 25 grams of protein. This translates into a little less than 100 grams of cooked meat or fish, 7 egg whites or a cup and a half of cooked lentils.
Assuming that an anabolic response occurs after each meal then it would not be unreasonable to suggest a target of 25 grams of high quality protein as an optimal figure for each meal for at least two days after a session of intense resistance exercise. Unpublished studies suggest that the amount of protein required to maximally stimulate protein synthesis after resistance exercise is similar if not slightly lower than that needed at rest. So from the perspective of maximizing muscle mass, meals consisting of 20-25 grams of protein might be sufficient. However the role of carbohydrates in the scheme of maximizing muscle mass should not be ignored in this equation, as insulin also plays a role in permitting protein synthesis and also appears to inhibit muscle breakdown. That being said, evidence exists that ingestion of small amounts of essential amino acids in conjunction with carbohydrates can temporarily increase muscle protein anabolism. So it isn’t just a matter of eating only high protein meals, as some carbohydrates must be included for optimal protein synthesis. Equally important is the matter of timing. Several studies suggest that best results in terms occur when protein is consumed immediately to an hour after exercise. [15,16,17,18,19] It bears noting that as convenient as protein shakes and bars may appear as intelligent choices for post exercise protein sources, the quality can be questionable and it is still a highly processed food source. Naturally occurring high protein foods always offer a better alternative- (see my article on protein shakes for a detailed discussion on the topic).
The Argument Against Excessive Protein Intake
As clear cut as this may sound as a recommendation for optimal protein intake for those engaged in resistance exercise, it bears noting that there is yet no evidence that the transient anabolic responses brought on by consuming adequate protein after resistance exercise lead definitively to a significant increase in muscle mass over a prolonged training period. It gets even more complicated, as research also suggests that higher protein intakes while exercising may lead to an adaptive response whereby the body compensates by increasing its capacity for amino acid breakdown. [20,21,22] Studies of habitual high protein diets consisting of 1.8 grams of protein per kilogram of bodyweight found that oxidation of the essential amino acid leucine increases as a result of the higher dietary protein intake while at rest and during moderate exercise. Thus eating more protein may not necessarily lead to better muscle building results as the pathways to amino acid oxidation appear to adapt to relatively high protein loads by increasing its capacity for catabolism.[20,21,23] It sounds counterintuitive but in a nutshell, the more protein you eat- the more protein your body sees fit to breakdown. There is also no evidence that habitual training increases protein requirements. On the contrary protein metabolism may become more efficient as a result of such training - allowing us to do more with less.
Possible Harmful Effects Of High Protein Intakes
Given the inescapable ‘more protein equals more muscle’ mantras in the fitness industry, (which may have more to do with the advertising reach of a multi-million dollar protein supplement industry than anything else), truly science based findings are quickly drowned out in favor of those that support a profitable point of view. The standard practice for most athletes is very much a shotgun approach- where large amounts of protein are consumed in the hope that it will be sufficient for their muscle building and performance needs. Surveys of bodybuilders and strength athletes indicate that some have protein intakes on average in the range of 2-2.5 grams of protein per kilogram of body weight. Numbers that many would recognize as closer to the recommendations found in muscle magazines and websites which call for 1 gram of protein per pound of body weight, to as high as 3 grams of protein per kilogram. [25,26,27,28,29,30,31] In my experience these figures seem a bit on the lower side I have known many athletes to eat as much as 4-5 grams of protein per kilogram of body weight. Numbers that are several magnitudes above the RDA, especially among those using anabolic steroids. Among non drug using athletes such intakes may not necessarily lead to better results but the real question is whether such high protein intakes are safe.
One of the most often cited health risks from high protein diets is renal failure and potential reduction in bone mass. Like the call to simply eat more protein for more muscles, these arguments don’t hold much water. Several populations, such as the Northern Canadian and Alaskan Inuit people, consume up to 3 grams of protein per kilogram of body weight throughout the course of their lives without any negative health effects related to their protein intake. [32,33,34,35] Loss of bone mass from higher protein intake was initially found in some studies. However extensive further research has shown that the relationship between high protein intakes and bone mass may be a positive one. In fact the more protein you ingest, the greater the peak bone mass achieved.[36,37,38,39] As for possible fears of reduced kidney function, the Institute of Medicine, (it was the IOM that established the current RDA standard in 2005) extensively reviewed the possible effect of a high protein intake on renal disease before making their final conclusions. In so doing they found that protein intake is not related to decline in kidney function over time. Other studies have validated this conclusion [41,42,43] for healthy adults without pre-existing renal disorder. Interestingly enough, other studies have actually found a positive link between higher protein intake and a reduction of risk for kidney disease, hypertension, obesity and diabetes. [44,45,46,47,48]
Positive Effects Of High Protein Intakes- Muscle Preservation & Increased Body Fat Reduction
While there is little cause for concern in terms of adverse effects from a high protein diet, there are several benefits to such a dietary approach. Studies have shown that there is a marked reduction in body fat and an apparent ‘muscle sparing’ effect when eating a (negative energy balance) calorie restricted high protein diet combined with an exercise program.[5,45] In fact high protein diets have consistently been shown to lead to greater weight loss, fat loss and preservation of muscle mass as compared to lower protein diets. Can you eat too much protein? And the answer is indeed affirmative and it would be any figure over 35% of your total energy intake assuming a state of caloric balance. There is only so much food that anyone can eat and a diet too high in protein will ultimately limit how much carbohydrates you can ingest. Carbohydrates that are essential for peak performance in all high intensity anaerobic activities such as weight training or sprinting. [41,49,50,52] Let’s not forget as well that consuming carbohydrates with protein after exercise increases muscle protein synthesis [7,53,54,55,56,57] so it is always in your best interest to think in terms of balancing the two macronutrients and not focusing only on a high protein intake.
Increasing Muscle Mass With Relatively Low Protein Intakes
It is interesting to note that modern ways of thinking presupposes a need for huge amounts of food to be able to build an impressive physique. From an evolutionary point of view, humans did have the privilege of eating huge amounts of protein five to six times a day over the past 150,000 years. On the contrary- food was almost always in short supply and we evolved over time to be able to deal with periods of famine. Adaptations that allow us to make the most out of very small amounts of macronutrients so that we would still be able perform the very high performance tasks required for survival under physically harsh and often nutrient scarce conditions. Our problems with obesity stem from these very adaptations- as we are by design created to store and hold on to excess energy in the form of body fat in preparation for times of famine. A design that has led to the epidemic levels of obesity given today’s superabundance of food. From a biological point of view, protein intake is no different as the human body is designed to adaptively build muscle and increase performance without a need for excessively high amounts of food. A cursory look at the well-muscled men and women in what we term primitive societies naturally sporting the very physiques that we in the West strive so hard to attain is a case in point. Though they might eat diets that are high in protein, their food supply is nowhere near that of an athlete or individual focused on increasing muscle mass in the Developed World.
One of the most remarkable observations I made growing up in the islands was the number of homeless individuals with incredibly muscular physiques. None of them probably ever got enough food to satisfy protein RDA recommendations and yet bulging biceps and rippling abdominals were the rule and not the exception. An observation anyone living in the tropics can readily attest to, but my own experiences also bear witness to the fact that outrageously high protein intakes may not be necessary for increasing muscle mass. As a teenager I was able to go from 125lbs to a contest ready weight of 185lbs within the span of three years eating a diet averaging only 100 grams of protein a day. That’s an increase of 60lbs and the protein intakes cited come from the meticulous documentation of my diet at the time. I had no access to protein powders nor did I have the financial wherewithal to afford to eat any more than I did, yet I seemed to have fared quite well on my diet of chicken, whole eggs, fish and peanut butter. Eating slightly more at 150 grams of protein a day I was able to go from 185lbs to 200lbs over the next three years following my initial growth spurt- significant gains in muscle mass that were never matched when I came to the United States. Even though at times I was eating well over twice as much protein as I did when I was back home in an attempt to implement the ‘standard protein requirements’ in the bodybuilding world.
Several of my natural bodybuilding colleagues on the African continent have similar if not more impressive stories- most notably Kenyan bodybuilding champion Fred Sanya- whose economic situation only allowed him one meal a day. Nonetheless he was still able to build a remarkable physique as were his peers in spite of their relatively low protein intakes. The studies cited give us some insight into how our bodies build muscle, but protein intake is obviously not the most important factor in increasing muscle mass. Training intensity and how it affects naturally occurring testosterone and other hormones are major components of the equation for supporting muscle and strength gains and might be even more important.
A compromised standard of 1.2 to 1.6 grams of protein per kilogram of body weight has been suggested as a possible guide for athletes.  An intake that may be best utilized with meals of 20-25 grams of protein with the inclusion of some carbohydrates as well. Some would consider these figures on the lower end of the spectrum, but they are well within the limits of the Acceptable Macronutrient Distribution Range (AMDR). Safe as such intakes may be they are more conjecture than anything else as no real evidence can show that they yield any additional benefit. It should be noted that most athletes don’t think much when devising their dietary regiments whether their diet works because of, or in spite of what they are consuming. A trend that holds true even among the elite.[58,59] What we can take away from all the findings is that timing, protein quality and consumption in conjunction with some carbohydrates can offer some tangible benefits and that a high protein diet promotes the greatest fat loss while preserving muscle mass while dieting. 
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Kevin Richardson is an award winning health and fitness writer, natural bodybuilding champion, the creator of Naturally Intense High Intensity TrainingTM and one of the most sought after personal trainers in New York City. Get a copy of Kevin’s free weight loss ebook here!
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