Protein...How much is too much?

Some days I would swear we were back in the 90's...then I look in the mirror, and see that my sweet, sweet MacGyver mullet is still gone.  What does remind me of the 90's however, is that fact that we seem to be right back into the Atkins Diet age.  Low Carb-High Protein diets have made such a strong strong resurgence, that I am considering growing my hair out again.  Well, maybe not...nobody looks good in a skullet!

Quite often these days, I am either asked or told about someone who has decided to jump back on the 90's Atkins train by either eliminating or significantly reducing carbohydrate (CHO) intake, and cranking up the amount of protein they are ingesting.

I have one word for those people...AMDR.  Okay, Okay...so it's an acronym, not a word.  So sue me.

The acronym AMDR stands for Acceptable Macronutrient Distribution Range, and basically refers to the appropriate (acceptable) levels of nutrients that we put into our bodies daily.  We need to keep in mind that anything can reach toxic or harmful levels within our bodies...even stuff that we typically consider healthy.

Take good 'ol H2O for instance.  Water, considered by some to be the fourth macronutrient, is something we take for granted.  We know we should be consuming specific amounts of this relatively benign liquid, to prevent dehydration...but have we ever thought much about hyper-hydration?  Did you know that the consumption of too much water can kill you?  

It's a similar situation with protein.  You can ingest too much protein, and it can have harmful, untoward effects on your body...and your performance.  The performance aspect is somewhat ironic, as the majority of people who overdose - yes, I said overdose - are those looking to improve their performance.  I've been there myself at times.

I was recently reading an article in a health and fitness journal about protein, that referred to protein as a substance that has a halo effect.  A halo effect is a phenomenon that leads people to overestimate the healthfulness of a food or nutrient, based on one quality.  Food manufacturers have capitalized to the tune of multi-billion dollar revenues by creating (and often simply re-labeling) new products that align with the halo effect that protein currently has.  

Don't get me wrong here...protein is absolutely essential to maintaining homeostasis, as well overall health and longevity...but the old adage "if some is good, then more is better" truly does not apply when we are talking about daily protein intake.

Let's talk Protein 101 here...

First, what is protein? 

pro·tein

ˈprōˌtē(ə)n/

noun

noun: protein; plural noun: proteins

1.

any of a class of nitrogenous organic compounds that consist of large molecules composed of one or more long chains of amino acids and are an essential part of all living organisms, esp. as structural components of body tissues such as muscle, hair, collagen, etc., and as enzymes and antibodies.

 

 

Above, is the definition of protein found in Webster's Dictionary.  Let's take it down a notch, and try to make it easier to understand.

For the purposes of this particular blog, protein can be defined as any food source or dietary supplement that is comprised of chains of amino acids.  You should know that there are complete proteins, and incomplete proteins.  Complete proteins are those that contain all of the essential amino acids, while those that are classified as incomplete, are deficient in essential amino acids.  

So what is the difference between an essential amino acid and a non-essential amino acid?  That is a great question!  

Essential Amino Acids are those that cannot be synthesized by the human body.  This means that we must consume them from food sources or dietary supplements.  There are ten essential amino acids, and most everyone who has a background in nutrition or exercise physiology, knows these as Private Tim Hall....or more accurately, PVT TIM HALL.

PVT TIM HALL is a common mnemonic that students use to remember the ten essential amino acids:

Phenylalanine

Valine

Tryptophan

Threonine

Isoleucine

Methionine

Histidine

Arginine 

Leucine

Lysine

Branched Chain Amino Acids (BCAA) were quite popular back in the nineties, and like many supplements, have come full circle.  What is old is new again.  Recent studies have linked BCAA with performance enhancement, especially when it comes to reducing fatigue levels.  This is due to BCAA's ability to be metabolized at the skeletal muscle level, rather than within the liver.  This means that BCAA's can stave off fatigue during training and competition, allowing you to push harder for longer durations.

Alright, let's talk about how much protein we should be getting.  Early on in this rant, I mentioned the word - sorry...the acronym AMDR (Acceptable Macronutrient Distribution Range).  But wait...there's another acronym out there that provides guidance for the quantity of nutrient intake - RDA (Recommended Daily Allowance).  The RDA provides quantities of food and nutrient intake, based on age and gender.

 "So" you ask, "What is the AMDR for protein?" 

The Institute of Medicine recommends an AMDR of 10-35% of total caloric consumption from protein.  This falls far short of the high protein diet fad recommendations of up to 50% total calories from protein sources.  The RDA for protein is as follows:

Recommended Dietary Allowance for Protein
	Grams of protein needed each day
Children ages 1 – 3	13
Children ages 4 – 8	19
Children ages 9 – 13	34
Girls ages 14 – 18	46
Boys ages 14 – 18	52
Women ages 19 – 70+	46
Men ages 19 – 70+	56

The next question one should ask is "What happens when I take in too much protein?"

There are a host of different outcomes of overdoing protein intake.  Some of them are as benign as gastrointestinal cramping and diarrhea.  If you are lucky, this is all that you will experience.  It is important to understand however, what happens to protein in your body.  The breakdown of protein cleaves nitrogen from the molecule.  Excess nitrogen levels in the body can create an acidic environment.  Acidic environments can be harmful to the body, and thus, the body strives to maintain nitrogen balance.  Athletes can benefit from a slight nitrogen balance due to their activity levels and need for muscle repair and synthesis.  The average person however, or the person who has adopted a high-protein diet in hopes of losing weight, may find that while they do lose weight (sometimes quite rapidly) their body fat levels do not drop in accordance to their total weight loss.

This condition is due to the fact that excess amino acid levels in the body, like any excess form of energy, can be converted and stored as adipose tissue...commonly referred to as fat.  Often times the significant weight loss comes at the expense of decreased lean muscle mass, and decreased body fluid levels.  

You see, when nitrogen levels begin to rise within the body, our amazingly designed 'machines' kick into protection-mode, forming greater amounts of urea, and stimulating an increase in urine production/output.  This is a mechanism used to rid the body of excess proteins and the byproducts of excess protein intake.

This may seem relatively unimportant, but it is important to understand that body fluid loss as little as 1% of total body weight, can have a profound impact on performance.  If you are an athlete, like me, the last thing you want to do is begin a training session or a competition...already dehydrated.

If you are not an athlete, and you are simply someone who has adopted the high-protein lifestyle to lose weight, it is also important for you to exercise.  You should strive to be well hydrated prior, during, and after any exercise session.

"So what else can happen if I take in too much protein?" 

For you women out there...excess protein intake can play a role in leeching bone-strengthening calcium from the body.  This can increase one's risk of developing osteoporosis later in life, which can lead to frequent bone fractures, and a significant reduction in quality of life.

Protein is good, but like anything else...too much, can be bad.  I encourage you to do additional research on your own, and make an informed decision about how you should eat...not a fad-based decision.  Fad diets and eating plans are rarely sustainable.  If you are an aging athlete like me, sustainability is paramount!

Here a just a few of the references for the information above, that you might find useful in your search for the truth.

AND (Academy of Nutrition and Dietetics). 2013a. Eat right for endurance.  www.eatright.org?Publication/content.aspx?id=7085;accessed June 1, 2013.

Bonjour, J.P. 2011.  Protein intake and bone health.  International Journal of Vitamin and Nutrition Research.  81 (2-3), 134-42

Tipton, K.D. 2011.  Symposium 2: Exercise and protein nutrition: Efficacy and consequences of very-high-protein diets for athletes and exercisers.  Proceedings of the Nutrition Society, 70 (2), 205-14

Westerterp-Plantenga, M.S., Lemmens, S.G., & Westerterp, K.R. 2012.  Dietary protein: its roe in satiety, energetics, weight loss and health.  British Journal of Nutrition, 108, s105-s102.