Researchers generally determine Protein quality by using the protein efficiency ratio (PER) or the protein digestibility corrected amino acid score (PDCAAS). They determine the PER by evaluating the weight gain in growing rats fed a particular protein compared with a standard protein, egg whites being the gold standard. The higher the PER value, the greater the protein quality. The PDCAAS was introduced as a more accurate way to evaluate protein quality for humans, because it uses human, not rat, amino acid requirements to calculate the amino acid score. It compares the amino acid profile of a protein with the essential amino acid requirements for humans according to The food and Agriculture Organization. When a protein meets this requirement, it gets a score of 1.0. PDCAAS has now been adopted as the official method by the World Health Organisation, the US Food and Drug Administration and the US Department of Agriculture.

Although the PDCAAS method is the internationally recognised standard for comparing Proteins for human consumption, it does not allow for differentiation among proteins with a PDCAAS of 1.0, so proteins can have different PERs while still having a PDCAAS of 1.0. This is significant, because researchers are now exploring how variances in specific essential and/or conditionally essential amino acids, as well as the availability of various peptides and micronutrients, affect human physiology. Claims of consumer-relevant superiority or inferiority, when performance of physique modificaitons are concerned, have yet to be supported by population-specific evidence in humans.

Protein

PCDAAS PER

Gelatin/collagen 0.08. --

Beef/poultry/fish 0.80-0.92. 2.0-2.3

Soy 1.00. 1.8-2.3

Ovalbumin (egg) 1.00. 2.8

Milk protein 1.00. 2.8

Casein 1.00 2.9

whey 1.00. 3.0-3.2

Bovine colostrum. 1.00. 3.0-3.2

Table 1

Table 1 (above) lists the PER and/or PDCAAS for the major types of protein used in nutritional supplements. The following discusses the relative strengths and weaknesses of these basic types of proteins that are often used as starting materials for nutritional supplements. Of course, adding deficient amino acids and other nutrients to these proteins may increase the PDCAAS, nutrient value and/or functionality of the protein.

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As you can see above collagen/gelatin is nearly useless to the human body. This is what is in almost all protein shots. Always check the ingredients. Many makers of protien shots are giving them names that have Whey in their title but are still using collagen/gelatin as their primary protein source.

Also keep in mind that ingredients on labels are listed in the order of amount used. So if collagen or Gelatin is listed first then it is the primary protein source for that product.

I think this should be pinned to answer the numerous posts about protein shots! Thank you for taking the time to find the research, OTR!

WOW!! thanks for some great & helpful info! It can be very confusing protein shopping. OTR - you have helped me more than you know as I am standing in the store aisles! :-))

Thank you for sharing this information with us.

Great information - Thanks!