In 1970, he became Director of the Clinical Research Center at the Harbor UCLA Medical Center, and the organizer of the First Fogarty International Center Conference on Obesity in 1972. Dr. Bray also Chaired the Second International Congress on Obesity held in Washington DC in 1977.
In 1989 he became the first Executive Director of the Pennington Biomedical Research Center in Baton Rouge, Louisiana, where he is now a Boyd (University) Professor and Professor of Medicine at the Pennington Biomedical Research Center of Louisiana State University in Baton Rouge His principal research grants have included several NIH-funded trials: The Dietary Approaches to Stop Hypertension which showed that a diet with high fruits and vegetable and low fat dairy products (the DASH Diet) lowered blood pressure; The Diabetes Prevention Program Outcomes Study which showed that weight loss and metformin will reduce the risk of developing diabetes; the Look AHEAD study which showed many benefits of weight loss in diabetics; The POUNDS Lost study which found no difference in weight loss over 2 years with 4 different macronutrient diets; and the Vitamin D and Prevention of Diabetes Study which is still on-going.
He is a member of numerous professional societies. In 1982 he founded the North American Association for the Study of Obesity (NAASO now The Obesity Society), and was the founding editor of Obesity Research, as well as co-founder of the International Journal of Obesity and the founding editor of Endocrine Practice.
His awards have included the Goldberger award from the AMA, The Willendorf Award from the IASO and the Osborne-Mendel Award from the American Society of Nutrition and the Johns Hopkins University Society of Scholars.