Hahn was one of the first to use the term "Naturheilkunde" (Nature Cure). In 1850, he managed Buchenthal water cure in Canton of St. Gallen, Switzerland.[1] In 1852, he became director of Tiefenau water cure in Canton of Zürich.[1] Hahn completed the second and third part of Rausse's book Instructions for the Use of Water Cure during 1851–1852.[1] In the early 1850s Hahn gave up alcohol, coffee, meat and spices.[3]
Hahn operated a naturopathic sanatorium Auf der Waid in Oberwaid near St. Gallen from 1862.[3] Medical Historian Karl Eduard Rothschuh commented that Hahn "started out exclusively with the water cure but with his addition of dietetics and vegetarianism to nature cure, he pushed its influence into the beginning of the health and life reform movement."[4] Hahn was influenced by Christoph Wilhelm Hufeland's book Makrobiotik and began to prescribe to his patients a lacto-vegetarian diet from 1852 that consisted of whole wheat bread, milk and uncooked vegetables.[5][6] Hahn's vegetarianism influenced Eduard Baltzer, Richard Wagner and many others.[5][7]
Hahn's Die naturgemässe Diät ("The Natural Diet") in 1859 argued against the meat-based diet that was promoted by Jacob Moleschott, Gabriel Valentin and others.[3] He argued for a meatless diet and provided evidence of its physiological benefits, including longevity and physical strength.[3] In 1865, Hahn authored a bestseller Das Paradies der Gesundheit, das verlorene und das wiedergefundene ("The Paradise of Health, the Lost One, and the One Regained").[5] Hahn also opposed animal vivisection.[3]
^ abcdefKirchfeld, Friedhelm; Boyle, Wade. (1994). Nature Doctors: Pioneers in Naturopathic Medicine. Medicina Biológica. pp. 49-53. ISBN0-9623518-5-7
^Lloyd, Iva. (2009). The History of Naturopathic Medicine: A Canadian Perspective. McArthur & Company. p. 46. ISBN978-1552787786
^ abcdeTreitel, Corinna. (2017). Eating Nature in Modern Germany: Food, Agriculture and Environment, c.1870 to 2000. Cambridge University Press. pp. 41-42. ISBN978-1-107-18802-0
^Rothschuh, Karl E. (1983). Naturheilbewegung, Reformbewegung, Alternativbewegung. (Nature Cure Movement, Reform Movement, Alternative Movement). Stuttgart: Hippokrates. p. 79. ISBN978-3777306155
^ abcBergdolt, Klaus. (2008). Wellbeing: A Cultural History of Healthy Living. Polity Press. p. 286. ISBN978-07456-2913-1
^Puskar-Pasewicz, Margaret. (2010). Cultural Encyclopedia of Vegetarianism. ABC-CLIO. p. 116. ISBN978-0-313-37556-9
^Lentz, Carola. (1999). Changing Food Habits: Cases Studies from Africa, South America and Europe. Harwood Academic Publishers. p. 183. ISBN90-5702-564-7