Fletcher’s central health claim was that thorough chewing, by extracting full nutriment and preventing the absorption of imperfectly prepared food, keeps the body free of disease. It is classified as mechanism_only: the claim rested on a posited physiological mechanism (“head digestion” and thorough insalivation) and on Fletcher’s own testimony of robust health, not on any measured disease outcome. It is recorded as refuted rather than merely untested because the broad claim, including assertions that the regimen could counter conditions from anaemia to alcoholism, is regarded in the medical-history literature as food faddism without scientific support (Christen and Christen, J Hist Dent 1997), and because Fletcher himself died of bronchitis in 1919, an ordinary infectious illness inconsistent with the immunity the doctrine promised.