Category Archives for "Protein Intake"

Protein Intake

Important dietary considerations for inducing muscular hypertrophy

During my competitive bodybuilding years I, just like everyone else in this particular field, was mainly interested in increasing my muscle size. This is no longer the case. Still, the science of inducing Muscle Protein Synthesis (MPS) and counteracting the Muscle Protein Breakdown (MPB) fascinates me a lot. It still applies to what I do, if not for any other reason, at least for the fact that being careless in this matter might result in losing muscle mass – and from there diminishing athletic performance. And, I care a lot about optimal athletic performance.

While I was researching my post on the methods for calculating protein intake, I stumbled on a meta study. In this post I want to examine this meta study alone. It’s quite interesting and, even more importantly, it is written in a language that a layman like me can easily understand. I encourage you to read the paper if you have time.

The name of the paper is, “A Brief Review of Critical Processes in Exercise-Induced Muscular Hypertrophy” and it could be found here. Of course, the paper includes references to other papers, based on which it draws its conclusions (in case you’re interested in the sources).

My notes are below. I’ve capitalized a few words here and there for additional emphasis. I did this only in places where the conclusion drawn ran counter-intuitive to popular belief (and counter-intuitive to many industry publications and the advertisers in them), or I didn’t know about it at all.

Regulation of muscle protein turnover

  • Resistance exercise in a fed state (with enough protein) promotes Muscle Protein Synthesis (MPS)
  • Resistance exercise in a fasted state promotes Muscle Protein Breakdown (MPB)
  • Addition of amino acids post-exercise suppresses the rise in MPB
  • Post-exercise (PE) hyperinsulinemia (from fast-digesting carbs with your PE protein) does not cause MPS, but it suppresses MPB
  • ONLY the essential amino acids (EAA) produce MPS
  • The EAA Leucine ALONE appears to be the metabolic trigger for MPS
  • Exercise increases the sensitivity to Leucine. Aging and inactivity decrease it
  • Post-exercise is the most optimal period for inducing aminoadicemia (eating protein) which in turn induces MPS
  • Protein synthesis in the muscles remains enhanced for at least 24 hours PE.

Protein dose and MPS response

  • Young people (in their 20-ies) achieve the same MPS with just 20g protein (0.25g/kg body mass/meal) PE that old adults (in their 70-ies) can achieve with close to 40g of protein
  • Beyond these levels of protein intake the amino acids are more heavily oxidized (not entirely used for MPS)

Protein quality and muscle protein turnover

  • Even a protein dose that is 25 percent of what is considered to be an optimal dose for MPS can become ‘optimal’ with the addition of the amino acid Leucine.
  • Whey is superior to casein in stimulating MPS despite the fact that it is only 20 percent higher in Leucine. This effect of superiority is due to the fact that whey is digested much faster than casein
  • Proteins with naturally higher Leucine content (whey) are superior for inducing MPS when compared to proteins with naturally lower Leucine content (soy).

Protein and weight loss

  • High-quality protein in doses that are higher than the normally consumed (15-17 percent of calories is what’s normally consumed) has a ‘sparing’ effect on muscle tissue only when the calorie deficit is not huge. The higher the calorie deficit the less muscle-sparing effect of protein

Strategies for increased MPS

  • Addition of carbohydrates to a protein meal PE: 1) serves to reverse the exercise-induced suppression of protein synthesis, and 2) helps restore glycogen stores
  • Glutamine, taken alone post-exercise (PE) does NOT augment MPS
  • Arginine, a precursor to nitric oxide, has NO effect on nitric oxide concentration even at large doses (10g). Nitric oxide dilates (widens) blood vessels, therefore it potentially promotes increased flow of nutrients and hormones to muscle tissues.

 

Methods for calculating total daily protein intake

In my last article I wrote about the different dietary protein needs in general. I also expressed that although it is clear who needs baseline protein levels (current RDA), who needs more than that and who needs less, it is still not very clear how to determine the exact needs for each individual.

In order to determine exactly how much dietary protein an individual needs, IDEALLY, we need to know and be able to use ALL of the following:

  • His (or her) general lifestyle
  • Type and intensity of training, if any
  • Age
  • Gender
  • Morphological body type
  • Omnivore or vegetarian/vegan
  • Primary, secondary, tertiary, etc. sources of dietary protein and their approximate ratios in one’s diet
  • Macro nutrient (and more precisely protein) digestion efficiency (is the digestive system compromised in any way)
  • Individual tolerance to different sources of protein
  • Total and per-meal dietary carbohydrate ingestion levels (carbohydrates divert the use of protein from the body as a source of energy and direct its use toward body tissues recovery, rebuilding, etc., so may be less total dietary protein is needed if enough carbohydrates are eaten)
  • Nitrogen balance / nitrogen retention efficiency (1 full paper, not abstract)
  • Protein turnover – maintenance and growth
  • Protein synthesis –  maintenance and growth
  • Metabolic response of the different tissues (muscles, bones) to different types of dietary protein
  • Presence of metabolic syndrome issues and CVD (cardio-vascular disease), especially presence of insulin resistance and issues with other hormones, involved in the protein metabolism

Unfortunately, after some serious time spent looking for official papers I was not able to find the type of research that could help me devise an exact daily protein intake for a particular individual, based precisely on the points of inquiry I described above.  At the very least, this does not seem possible without using a very sophisticated lab (I can only guess).

Nonetheless, there is enough information that can at least provide us with a good starting point, which can represent a level of dietary protein intake that, with some perhaps minor adjustments and fine-tuning, could allow us to arrive to a relatively precise (for the particular time in one’s life) daily dietary protein intake levels.

Method, based on specific needs for total daily protein intake

These are the general numbers that can provide a starting point. Examples below.

(Tip: Use the instant kilograms to pounds converter at the bottom right if you don’t know your body weight in kilograms)

  • Sedentary individuals, in order to maintain zero nitrogen balance (nitrogen entering vs. nitrogen leaving the body), generally require 0.69g protein/kg/day (2), 0.66g to 0.83g/kg/day (3), and 0.8g/kg/day is the RDA (Recommended Dietary Allowance) for adults 19 and older. For simplicity sake I think it’s best to take the RDA’s number (0.8g/kg/day) as the zero nitrogen balance and work with it
  • Top athletes require 1.41g/kg/day (2)
  • Top male athletes require  2 x 0.8g (1.6g)/kg/day of dietary protein, and top female athletes require (0.8g + (0.8g x 0.5)) to (0.8g + (0.8g x 0.6))/kg/day. In other words, top female athletes require only 40-50 percent dietary protein in excess of the zero nitrogen balance requirements for sedentary individuals (0.8g/kg) (4)

My comments:

Not sure how to interpret “top athlete”. The Merriam-Webster dictionary defines “athlete” as “A person who is trained in or good at sports, games, or exercises that require physical skill and strength”. If I have to work with this definition and adapt it to “top athlete” it would probably be something in those lines: “A person who is trained to have superior abilities at sports, games, or exercises that require physical skill and strength”. A top athlete – for the purposes of establishing total dietary protein requirements – would be someone who trains intensely at least 5-6 times a week.

My personal suggestions for additionally modifying the baseline daily protein intake (o.8g/kg/day), based on activity level and intensity:

  • Recreational athletes – moderate activity exercise – 2 to 3 times a week: add 0.2g/kg/day protein to RDA level or a total of 1g/kg/day
  • Endurance athletes – long-distance running – 3 – 5 times a week: add 0.4-0.6g/kg/day protein to RDA level or a total of 1.2-1.4g/kg/day (along with higher carbohydrate intake)
  • Strength athletes – heavy weights lifting 4-6 times a week: add 0.6-0.8g/kg/day protein to RDA level or a total of 1.4-1.6g/kg/day (levels of daily protein intake above these do not show clear benefits as far as increase in muscle protein synthesis, and create nutrient overload – 2)

Example:

Subject: Female top athlete
Weight: 125 lbs (57 kg – using the converter – bottom right)

(0.8×57)=45.6
45.6×0.5=22.8
45.6+22.8=68.4g protein/day

Subject: Male, sedentary lifestyle
Weight: 175 lbs (79 kg)
0.8×79=63.2g protein/day

Method, based on the total daily calories requirements

There is an alternative way to determine the dietary protein levels. It’s based on total daily calories intake:

  • Dietary protein intake for sedentary adults is 12-15 percent of the total daily calorie intake
  • Dietary protein intake for active adults is 15-30 percent of the total daily calories intake. This depends on the level of activity – more active will require a higher percentage of dietary protein

The rest of the calories, after total daily protein is calculated, go toward total carbohydrate and fat intake.

Example:

Total daily calories: 2000

Subject: Sedentary individual (15 percent):
2000×0.15=300 (calories from protein)
300/4=75g/day

Subject: Very active individual (30 percent):
2000×0.3=600 (calories from protein)
600/4=150g/day

More comments:

I do not personally prefer the second method – it is far more general and less specific than the first method. However, the second method is easier to put to use.

Additionally, in my personal view the first method would be more accurate if it is used to determine the dietary protein intake for persons of normal body weight (not overweight or obese). I do not see a reason why one should provide extra protein by accounting for large quantities of fat as a part of total body mass. Fat is far less metabolically active tissue than muscle tissue and it does not need much protein at all.

So, how do you tell if you are of normal body weight?

Normal body weight is when the body fat levels are 20-25 percent for women and 10-17 percent for men. Essential fat (must have to be healthy.. and alive) for women is about 10 percent and for men is about 5 percent. So, we are talking about 10-15 percent above this essential fat level for women and 5-12 percent above for men (On the ‘Net you will find sources offering different numbers as to what’s a normal body fat percentage for women and men. The numbers above are my rounded up approximations, based on my experience as a heavy individual and as an extra lean competitive athlete. Also they are based on my personal observations of populations on two continents.)

Example:

The subject is a male, sedentary, body weight=225lb (102 kg), body fat percentage=30%.
Weight of fat tissue alone: 67 lbs (30.6 kg)
Weight of fat tissue above normal weight levels (at 17 percent body fat): 29 lbs (13 kg)
225-29=196 lbs (89 kg)
If protein requirements were calculated using the initial 225 lbs body weight, the total protein would come out to 81.6g/day
If protein requirements were calculated with the correction for excess body fat, the total protein would come out to 71.2g/day.
That’s more than 10g of extra protein a day – and more than 40 Calories extra a day – that the body simply doesn’t need.

So, when calculating total daily dietary protein requirements using the first method, I’d suggest that, if necessary, you make a correction of the total body weight and equate that to ‘normal’ total body weight.

– – –

If this article has any omissions or inaccuracies, please use the comments below to let me know. I will research and update the article accordingly.

How much protein should different people eat

Protein, as opposed to carbohydrates, is an essential macro nutrient – meaning you must have it in your diet because you can’t live without it – not for very long.

Different people have different demands for the amount of protein they should consume.

Earlier today I listened to a podcast by Chris Kresser. Chris discussed a topic that isn’t often discussed even in the nutrition and diet circles – ‘Should you eat more protein in your diet’.

I urge you to head over to Chris Kresser’s website and listen to this podcast.

The take-away points of his talk – the way I understand it – are:

  • We have a feed back system in our brains that tells us how much protein we need – if we need more we crave it, if we need less we eat less of it. So, eat as much protein as you crave (that’s Chris Kresser’s general advice on protein)
  • In some people this feed back mechanism in the brain does not work properly. It could be due to inflammation in the brain or other disease
  • Most people who lead normal lives are fine with 15 percent protein intake, based on total calories consumed. 15 percent is the average protein consumption in the western countries
  • Some individuals require less protein in their diets. Those include individuals with pre-existing kidney disease and pregnant women
  • Some individuals require more protein. People that need more protein in their diets include: athletes, individuals on a fat loss diet, individuals with metabolic and blood sugar health issues, people with adrenal fatigue syndrome, people that waste muscle tissue (elderly and those with wasting diseases)
  • If you require higher protein intake for recovery and re-building you cannot rely on this feed back mechanism. You have to know that you need more
  • Wholesome sources of protein are better than highly-processed sources (like protein powders)
  • But, when it makes sense (very high protein demands and costs of wholesome sources, or disrupted digestive processes – inefficient bile or stomach acid, etc.) protein powders are a reasonable addition to the diet
  • Animal protein sources are better (more bioavailable) than plant protein sources
  • Dairy proteins are the most bioavailable, followed by eggs and meat
  • Non-denatured whey is better (I have an article on this, too)
  • Hydrolyzed(partially digested) beef protein powder is another good choice – especially if it includes collage protein in it. It is balanced better as far as amino acids – it doesn’t have over-abundance of certain amino acids (like methionine from pure lean meats and whey)
  • If plant proteins must be used – pea protein is a good choice, especially if it is hydrolyzed (I used to use pea protein in baking when I had my specialty bakery)

This is all good info, but the question that remained unanswered for me is: ‘If a person requires more protein in their diet how much exactly should that person eat? How much is too little? How much is just enough? And, how much is too much?

These are questions that I want to find answers to. I am trying to practice and master extreme calisthenics (still an amateur, but..) and these bodywegith workouts could be very, very demanding.

And, there are subtleties, too. For example, if you eat more protein (and calories) than you need you gain too much mass and become too heavy. If you eat less you don’t recover well and your performance suffers.

So, I am personally interested in knowing exactly how much protein should I eat daily, based on my personal activities and lifestyle so that I recover well enough but don’t gain even an ounce of non-efficient mass (fat).