Aajonus has pointed out that the ptyalin in human saliva will interfere with meat digestion and recommends chewing as little as possible. Many here also recommend this. But ptyalin is an amylase, and an amylase's job is to begin the conversion of starch into sugar. Ptyalin's job specifically is to accomplish this with the chewing process. Many people (non-RPD) would undoubtedly point to the presence of amylase in saliva as prima facie evidence that man is meant to eat starchy vegetables. Else, they would argue, why would we have this adaptation if it served no use? Its a good argument. Indeed the presence of ptyalin in saliva appears to be a digestive adaptation to eating something starchy, on the basis that the resultant sugars are needed by some metabolic processes. However, it falls short in assuming that only starchy veggies have starch, which many here know to be false, as certain organs (liver) are relatively high in glycogen, an animal starch. The original claim that ptyalin interferes with protein digestion seems rather odd, considering that its job is starch digestion.