David is well recognized for his nutritional research and is credited with developing the concept of glycemic index as a way of explaining how dietary carbohydrate impacts blood sugar. Our dietary plans were influenced by his research, which includes over 15 clinical studies on the glycemic index.

He received his scientific degrees from Oxford University and is a fellow of the Royal Society of Canada: the Academies of Arts, Humanities and Sciences of Canada. He's the international editor of the Journal of the American College of Nutrition, and the author of numerous published scientific articles on dietary intervention in the management of disease and reduction of risk factors.

He's also actively practicing medicine. David's a staff physician in the endocrinology division of St. Michael's Hospital in Toronto, as well as the director of its Clinical Nutrition and Risk Factor Modification Center. He also serves as an associate physician on the gastroenterology staff at Toronto General Hospital.