Hi Dan!
I didn't know what is "self muscle testing" and I had to search.
Our body can reliably tell us if a food is good or bad for us only if that stuff is completely natural, raw, unprocessed, unmixed and un-spiced. The nose is just over our mouth to check what we intend to put in. Smell and (or) taste is how all animals choose their food, and humans are animals.
What else can I tell you? If you want more info, you're welcome: don't hesitate to ask me and I'll try to answer within the limits of my limited knowledge and understanding.