After a long break, we have a new manuscript. Currently, this is a preprint published at Preprint.org, an open-access platform. "Preprint" means that it has a DOI number and it can be cited by any other scholarly article. This article is about the C-peptide as measured in non-T1DM patients. Here, we highlight its use and usefulness in the follow-up of patients undergoing dietary intervention therapy. Most importantly, in the article, we point to the very real danger of misdiagnosing low-carb dieters as T1DM patients as a result of low C-peptide levels, specifically when seen in combination with ketones in the urine. Practitioners (including diabetologists) should not dismiss patients following low-carb diets or the knowledge coming from patients following unconventional yet entirely scientific approaches to regain health. preprints.org/manuscript/202…