Dr. Poston has graduate degrees in the behavioral sciences (University of California, Santa Barbara) and epidemiology (University of Texas Houston Health Science Center, School of Public Health).

Dr. Poston completed postdoctoral fellowships in Behavioral Health Psychology (Wilford Hall Medical Center) and in Cardiovascular Health (American Hospital Association Health Forum). His research focuses primarily on the areas of obesity, tobacco control, and cardiovascular disease prevention with an emphasis on minority populations and military and first-responder health.

He has been a principal investigator or co-investigator on grants from the American Heart Association (AHA), the American Legacy Foundation, the National Heart, Lung, and Blood Institute, the National Institute of Digestive Disorders and Kidney Diseases, the Agency for Healthcare Research and Quality, the Department of Defense US Army Medical Research and Material Command, and the Department of Homeland Security/FEMA. He also has been the recipient of a Minority Scientist Development award from AHA.