Reaven's work on insulin resistance and diabetes mellitus with John W. Farquhar goes back at least to 1965.
Still, Reaven believes that contemporary criteria are arbitrary and that it may not be necessary to define it as a diagnostic entity more than a pathophysiological parameter.
After research work in Stanford and two years in the U.S. Army medical corps he completed his residency at the University of Michigan.
He then took up a US Public Health Service research post at Stanford, where he progressed to a full professorship in 1970.
[6][7] Apart from his work at Stanford he was also Senior Vice President for Research for Shaman Pharmaceuticals, Inc. in South San Francisco.