Originally posted on futurefood.hellobox.co.
LabDoor is an independent testing firm that analyzes foods and supplements. In the linked report they compared 81 protein supplements, analyzing each for their actual nutritive contents as well as for contaminants like heavy metals.
(None of the complete meal replacements we focus on are included in this set. Labdoor’s analysis of Soylent is here. They don’t seem to have reviewed any other meal replacements.)
Scroll down in the linked page, or click “Report” at the top, to find the discussion. One interesting point is that they have no issues with Soy protein and make no reference to the internet controversies about it. Another “surprising” finding is that many products contain free-form amino acids which
spike protein content in standard laboratory tests but add little nutritional benefit
Free-form aminos are isolated chemicals, as opposed to amino acids that are bound up as the “lego brick” building blocks of soy or whey protein molecules. It isn’t clear to this reader whether they have “little nutritional benefit.” I couldn’t find much about them, but this article from a body-builder website thinks they are just fine,
Unbound or free form amino acids can access the general circulation within 15 minutes. Thus the use of branched chain amino acids during training helps to fight fatigue and helps muscles to recover after a strong effort.
I suppose LabDoor’s point is that amino acids are not proteins, whereas the products they are reviewing claim to be protein supplements. For this reason they subtract the free aminos from the nominal test results, which results in some products having less protein than their labels claim.