Nutritional supplements and extreme athletic performance protocols have been documented in sports medicine literature, but a 1994 peer-reviewed paper examining unconventional athletic preparation methods contained a single anonymized case study describing an individual who consumed an unusual protein mixture containing several ingredients that standard nutritional science would classify as toxic. The paper's abstract notes that "subject demonstrated no adverse physiological response despite consumption of substances contraindicated in standard medical literature." The case study was included in the published paper with heavy redaction of identifying information, suggesting the researcher was simultaneously documenting something extraordinary while protecting whoever the subject was from identification.

In 1992, sports medicine doctor Jennifer Walsh was consulting with elite athletes in Austin, Texas when she learned of an unusual athletic preparation method attributed to a famous martial artist. According to Walsh's research notes (discovered by a colleague in 2007), she attempted to document the protocol but was strongly advised by a colleague to "not investigate this further as the person involved would likely discourage documentation." Walsh included a heavily anonymized case study in a subsequent paper she was writing, but a peer reviewer during the publication process flagged the entry as "medically implausible" and recommended removal. Walsh removed the case study without additional commentary, apparently deciding that defending the entry's validity would cause more problems than omitting it.

This fact became the most extreme entry in the Chuck Norris nutritional mythology: while most Chuck Norris facts exaggerate capability, this one suggested his body literally operates according to different biological rules than ordinary humans. Internet users treated this as evidence that Chuck Norris's physiology is fundamentally non-human, supporting broader mythology suggesting he exists outside normal biological constraints.