He graduated from the New York University Medical College in 1891 and spent 16 years in regular medicine and surgery, specializing in the latter. He later discovered he had Bright's disease, and was unable to cure it using accepted medical methods of the time. This led him to find alternative methods to rid himself of disease. He came up with the concept of food combining (also known as the Hay diet), the idea that certain foods require an acid pH environment in digestion, and other foods require an alkaline pH environment, and that both cannot take place at the same time, in the same environment. After allegedly curing himself through proper diet, he wrote several books, started a sanatorium, and lectured throughout United States and Canada.