Protein Basics

On January 15, 2010, in Protein, by Andrea


As important as it is, protein is perhaps one of the most confusing topics in the WLS world – even though there is a ton of research and information available about it out there.

Protein is an important macronutrient required to help maintain and build muscle mass within the human body.  Without protein, the body will not have the requisite materials to keep the heart beating, legs walking, or arms moving.

Protein, during digestion, is broken down into it’s components to provide amino acids.  Amino acids are building blocks of proteins and are critical in various biochemical reactions throughout the body on the molecular level – without them, our mood, energy, brain function, ability to move, EVERYTHING is affected.  Some of these amino acids can be synthesized by the body using other amino acids as building blocs, but there are nine according to one accepted classification (eight by another, even ten by even another) that must be provided by the diet called Indispensible Amino Acids (IAA’s) or essential amino acids.  The IAA’s are:

  • Isoleucine
  • Leucine
  • Valine
  • Histadine
  • Lysine
  • Methionine
  • Phenylalnine
  • Threonine
  • Tryptophane

Additionally, there are three conditionally indispensable amino acids, so-termed depending on the body’s ability to synthesize them.  They are:

  • Arginine
  • Cysteine
  • Tyrusine

Lastly are the dispensable amino acids.  These are amino acids the body can synthesize given that it has enough of the basic building blocks to create them.  These are also found in food and supplements — the body does not have to create these if we consume enough in dietary or supplemental sources.  The DAA’s are:

  • Alanine
  • Aspartic Acid
  • Cystene
  • Glutamic Acid
  • Glutamine
  • Glycene
  • Ornithine
  • Proline
  • Serine
  • Taurine

The content and ratio of these amino acids in your foods and protein supplements are the things that control the quality of the food or supplement that you are ingesting.

Bioavailability of protein has been measured in a number of ways for years.  Rats have been fed various diets and their fur growth has been measured as a way to determine digestibility of protein – this especially rings true as the standard test for protein in foods and supplements actually looks for nitrogen, not protein.

Depending on the industry, you are likely to see any number of protein quality measurements – of course using the one that makes their particular product look best.

PER (Protein Efficiency Ratio) — Basically, various combinations of proteins were given to young rats; their growth was then measured.  A PER above 2.5 was considered excellent.  This method gave too much weight to the importance of methionine, which is more important to developing rat hair than it is in human nutrition.

NPU (Net Protein Utilization) — Outdated and seldom used, egg protein given a score of 94; 100 would indicate that every bit of protein eaten would be used to produce lean tissue

BV (Biological Value) — Also generally considered outdated; evaluates protein based on amount of nitrogen retained in body after absorption of a protein food; egg is the standard and highest value possible is 100 (despite some products selling tactics)

PDCAAS (Protein Digestibility Corrected Amino Acid Score) — In 1991, the World Health Organization adopted the PDCAAS method of protein scoring.  In this method, the amino acid profile of the food or supplement in question is compared against a standard amino acid profile.  PDCAAS looks at the limiting amino acid – meaning that if a food is completely missing one of the IAA’s, it has a score of 0.  Rather than score the protein on what it has, the PDCAAS scores on the lowest common denominator – on what it does not have.
While PDCAAS is the preferred scoring method supported by the NIA and WHO, it is not the end-all to protein scoring.  While many see it as the most reliable, it does have it’s criticisms as well.  If a food product is missing just one IAA, it has a PDCAAS score of 0; however the same food item paired with another item that has that missing amino acid will work together to create a complete protein, raising the PDCAAS score – potentially even to the max score of 1.  The question, of course becomes how soon do the two food products have to be consumed to be of benefit to one another?  There’s some speculation and the answer, typically depends on the industry involved.  For example, the collagen protein industry would like for you to believe that the IAA’s they are missing can be made up through the diet.  There are two flaws with this argument:  first, the IAA’s collagen is missing are the ones many diets are typically low in, thus the shortfall still exists; second,  there is a time frame, albeit it’s one of those wishy washy mythical numbers that tends to get turned into rules of law when said too many times sorta deal for you to consume the missing IAAs so we really don’t know what the number is deal.  Sometimes, it’s just easier not to have to plan your protein supplements that much.

Beyond the basics (I know, I know — THAT was basic?), the next question invariably comes into type of protein supplements.  The typical supplements are made from whey (milk product), soy, and egg.  Beyond the type of protein, which simply states where it came from, you have classifications of concentrate and isolate.

Concentrates are proteins that are typically concentrated through dehydration to remove the moisture.  The process will leave some things like lactose in whey, fat, and sugars behind and are only about 60-70% protein by dry weight.

Soy and whey isolates, however, have been further filtered to remove additional impurities.  It is this process that leaves whey protein isolate lactose-free as this is one of the molecules removed through filtration.  In the end, isolates are 90-95% pure protein, and have less taste due to fewer contaminates within the protein itself.  Additionally, within the isolate market, there are grades of isolates — depending on the company purchasing and marketing the product, you may get “A” grade isolate or “B” grade.  The quality is typically a taste difference — although there are a few small differences as well.

Typical protein supplements will have combinations of protein types.  The more expensive proteins will be the isolates due to the expensive filtration process.  It is said that isolates will absorb better, but in many cases it is thought that blends will absorb just as well.

A special note about collagen bullets: Collagen, in of itself, has a PDCAAS score of 0.08 and a PER of 0.  Knowing this, the companies marketing these products have added just enough whey protein to give a minor amino acid profile, but not enough of one to benefit unless you drank several gallons worth.  Additionally, these proteins will deflect their inferior amino acid profile by highlighting their “hydrolyzed” content.  Hydrolyzation, which is the process of breaking up protein molecules, is actually how collagen protein is created.  This process of hydrolyzation is how the collagen is rendered from the carcasses of the animals it once came from.  So while hydrolyzed protein is neither good nor bad — the fact that collagen is using it as a selling point is a bit under-handed here.  Along the same vein, if we absolutely needed our food to be hydrolyzed, then we would waste away — because the chicken in our sandwich hasn’t been pre-digested for us, and neither has that steak you ate last week.

There is much controversy when it comes to protein amounts needed by adults.  The current reccomendation is 0.8g/k or 0.37g/lb of body weight, which works out to a nice 59.2g for a 160lb person.  Looking at this number, it’s not hard to believe why some groups feel this number is severely understated.

However, if you were to plug in the same numbers for an obese individual — say someone weighing 350lbs — the same formula has the need at 129.50g per day, which seems a bit high.

If we really want to get fun and interesting, let’s look at WLS concerns.  What about the malabsorption component?  How much protein should we factor in for that?  Current recommendations for normies is that no more than 35% of their daily calories come from protein, but with such strictly restricted carbohydrate diets, many post-0ps have protein amounts in the 40-50% range.  How does this measure up with recommendations?

So while there is plenty of research on the amount people should eat, there are still no hard and fast rules — yet.  So that means there are even fewer rules when it comes to US.

PDCAAS and PER scores for common foods and supplements.  PDCAAS scores out of 1; PER above 2.5 considered good

PDCAAS:  0.08
PER:  0

PDCAAS:  0.8 – 0.92
PER:  2.0-2.3

PDCAAS:  1.0
PER:  1.8 – 2.3

Egg White
PDCAAS:  1.0
PER:  2.8

Milk Protein
PDCAAS:  1.0
PER:  2.8

PDCAAS:  1.0
PER:  2.9

Whey Protein
PER:  3.0-3.2

Special thanks to Jerome at Unjury for going over some of this info with me.

Information compiled from National Academies Press: Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients)

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2 Responses to “Protein Basics”

  1. MacMadame says:

    This is great, but I wish you’d included some info about the bogus “no more than 30 g in an hour” rule. I’d like a one-stop-shop article I could include in my response to that one.

  2. Andrea says:

    You know, honestly it escaped my attention because I don’t even think about it being a fact. I’d also like to find a specific source that can discredit the fallacy to cite before I list it as well — I’m sure I’ll add that at some point along the way.

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