Advice about choosing a bodybuilding protein is often misleading and based on unscientific opinion or irrelevant research studies on starved rats. This is fine if you are starved rat. If you want to boost bodybuilding, though, here is what you should know.

Flaws in Common Opinion

The idea for consuming a bodybuilding protein is that it goes into building muscle tissue. The obvious research should, therefore, show how proteins from different food sources end up in muscle. Here is how a typical piece of advice by a well-known bodybuilder would incorrectly imply this kind of result:

The following quote was taken from this article: How To Choose the Best Protein Supplements for Achieving Your Bodybuilding Goals: Everything You Need To Know About Choosing Protein Supplements by Hugo Rivera.

There are many sources of protein from which protein powders or bars can be made. Protein quality is measured by Biological Value (BV). BV is a value that measures how well the body can absorb and utilize a protein based on nitrogen retention. The higher the Biological Value of the protein you use, the more nitrogen your body can absorb, use, and retain. As a result, proteins with the highest BV promote the most lean muscle gains. Whey protein has the highest BV value, rating at 104. Egg protein is only second to whey rating as a 100 with milk proteins being a close third rating as 91. Beef rates as an 80 with soy proteins a distant 74. Bean proteins, due to the fact that are plant-based proteins, only rate a 49. Now that we have discussed BV values, let’s discuss each protein source in more detail.

The key to the above comment is: …proteins with the highest BV promote the most lean muscle gains.

This got my curiosity, since I like to think about these kinds of statements as open to scientific research. Even though the comment sounds logical, let’s see how it stands up to the evidence that scientists have discovered.

Irrelevance of Biological Value

Fortunately, I didn’t have to look too hard, since Wikipedia has so much good information on this topic. Oh, you have to beware of Wikipedia, too, since the information there can be still be incorrect. What I do to judge Wikipedia entries is to go to the original sources that are cited in the article to see how good they are. In so doing, this is what I found to be true about Biological Value on Wikipedia:

Since the method measures only the amount that is retained in the body critics have pointed out what they perceive as a weakness of the biological value methodology.[17] Critics have pointed to research that indicates that because whey protein isolate is digested so quickly it may in fact enter the bloodstream and be converted into carbohydrates through a process called gluconeogenesis much more rapidly than was previously thought possible, so while amino acid concentrations increased with whey it was discovered that oxidation rates also increased and a steady-state metabolism, a process where there is no change in overall protein balance, is created.[18] They claim that when the human body consumes whey protein it is absorbed so rapidly that most of it is sent to the liver for oxidation. Hence they believe the reason so much is retained is that it is used for energy production not protein synthesis. This would bring into question whether the method defines which proteins are more biologically utilizable.

A further critique published in the Journal of Sports Science and Medicine states that the BV of a protein does not take into consideration several key factors that influence the digestion and interaction of protein with other foods before absorption, and that it only measures a proteins maximal potential quality and not its estimate at requirement levels.[19] Also, the study by Poullain et al., which is often cited to demonstrate the superiority of whey protein hydrolysate by marketers, measured nitrogen balance in rats after three days of starvation, which corresponds to a longer period in humans.[20] The study found that whey protein hydrolysate led to better nitrogen retention and growth than the other proteins studied. However the study’s flaw is in the BV method used, as starvation affects how well the body will store incoming protein (as does a very high caloric intake), leading to falsely elevated BV measures.[21]

So, the BV of a protein is related to the amount of protein given. BV is measured at levels below the maintenance level. This means that as protein intake goes up, the BV of that protein goes down. For example, milk protein shows a BV near 100 at intakes of 0.2 g/kg. As protein intake increases to roughly maintenance levels, 0.5 g/kg, BV drops only around 70.[21] Pellet et al., concluded that “biological measures of protein quality conducted at suboptimal levels in either experimental animals or human subjects may overestimate protein value at maintenance levels.” As a result, while BV may be important for rating proteins where intake is below requirements, it has little bearing on individuals with protein intakes far above requirements.

This flaw is supported by the FAO/WHO/UNU, who state that BV and NPU are measured when the protein content of the diet is clearly below that of requirement, deliberately done to maximize existing differences in quality as inadequate energy intake lowers the efficiency of protein utilization and in most N balance studies, calorie adequacy is ensured. And because no population derives all of its protein exclusively from a single food, the determination of BV of a single protein is of limited use for application to human protein requirements.[22]

Another limitation of the use of Biological Value as a measure of protein quality is that proteins which are completely devoid of one essential amino acid (EAA) can still have a BV of up to 40. This is because of the ability of organisms to conserve and recycle EAAs as an adaptation of inadequate intake of the amino acid.[23]

Lastly, the use of rats for the determination of protein quality is not ideal. Rats differ from humans in requirements of essential amino acids. This has led to a general criticism that experiments on rats lead to an over-estimation of the BV of high-quality proteins to man because human requirements of essential amino acids are much lower than those for rats (as rats grow at a much faster rate than humans). Also, because of their fur, rats are assumed to have relatively high requirements of sulphur-containing amino acids (methionine and cysteine).

(The numbers in brackets refer to citations at the end of the article.)

I encourage you to go to the Wikipedia link and read the entire entry about Biological Value (there are two ways for listing it, for example) for yourself. In the immortal words of Commander Spock, “Fascinating!”

A Better Way to Judge Protein Sources

At the end of the entry on Biological Value is this brief comment on a much more meaningful to measure protein quality:

As a result, the analytical method that is universally recognized by the Food and Agriculture Organization (FAO), World Health Organization (WHO), the U.S. Food and Drug Administration (FDA), the United States Department of Agriculture (USDA), United Nations University (UNU) and the United States National Academy of Sciences when judging the quality of protein in the human is not PER or BV but the Protein Digestibility Corrected Amino Acid Score (PDCAAS), as it is viewed as accurately measuring the correct relative nutritional value of animal and vegetable sources of protein in the diet.[24][25]

If you are like me, you will want to follow that link to the PDCAAS entry on Wikipedia, too. This is it here: (PDCAAS.) The main point that you should pay attention to is the list of proteins in order of how useful they can be as bodybuilding protein, which is as follows:

A PDCAAS value of 1 is the highest, and 0 the lowest. The table shows the ratings of selected foods.[2][3][4]

1.00 casein (milk protein)
1.00 egg
1.00 soy protein
1.00 whey (milk protein)
0.92 beef
0.91 soybeans
0.78 chickpeas
0.76 fruits
0.73 vegetables
0.70 legumes
0.59 cereals and derivatives
0.42 whole wheat

Isn’t it interesting that casein, egg protein, soy protein and whey protein are all equivalent? Those comments by Mr. Rivera sure look to be off base. Choosing a good protein for bodybuilding purposes isn’t as complicated as he (and lots of bodybuilding gurus, by the way) make it out to be.

Just some good food for thought (pardon the pun…I couldn’t resist!).

By the way…

The best books that I know of for showing you how to stay fit with quick, simple, at-home workouts are the Lightning Speed Fitness Program by Roger Haeske and the Fit Over 40 for Women by Brett Yokley. Roger and Brett also throw in lots of bonus books on diet, exercise, and lifestyle when you purchase their books. Click on images below for details.

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All the best in natural health,

Dr. D

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