David Raubenheimer, PhD, is the Leonard P. Ullman Professor of Nutritional Ecology in the School of Life and Environmental Sciences, and Nutrition Theme Leader in the Charles Perkins Center at the University of Sydney. He lectures extensively at universities and conferences around the world. He is the co-author with Stephen J. Simpson of The Nature of Nutrition: A Unifying Framework from Animal Adaptation to Human Obesity.

Stephen J. Simpson, PhD, is academic director of the Charles Perkins Center and professor in the School of Life and Environmental Sciences at the University of Sydney. He is the recipient of the numerous awards, a Fellow of the Royal Society of London, and a Companion of the Order of Australia. He has appeared on National Geographic, Animal Planet, and the history channels in the United Kingdom and also as the presenter of a four-part documentary series for ABC TV, “Great Southern Land.”