Buchinger studied medicine at the Ludwigs-University in Gießen, Germany. After his promotion he went to the German Navy as an army physician. In 1917 he was discharged due to illnes, he suffered from tonsillitis that never completely healed and led to rheumatism in his joints. According to his daughter, on the advice of a physician colleague, the fasting doctor Gustav Riedlin, he tried fasting for the first time and after the 19th day of fasting, his condition started to improve rapidly. He then turned with full interest and enthusiasm to fasting as a therapy.
In 1920 he founded his small fasting clinic in Witzenhausen in Germany. Later in 1935 he founded his first real sanatorium in Bad Pyrmont. In that year developed the fasting method and described it in his book, "The Therapeutic Fasting Cure", published in the same year. In 1953 he founded a new clinic at Überlingen, together with his daughter Maria and son-in-law Helmut Wilhelmi. His grandson Raimund Wilhelmi leads the Buchinger Wilhelmi clinic in Überlingen with his wife Francoise Wilhelmi de Toledo.