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 Centre, at the University of Sydney. He lectures extensively at universities and conferences around the world. He co-wrote The Nature of Nutrition: A Unifying Framework from Animal Adaptation to Human Obesity with Stephen J. Simpson. He lives in Sydney, Australia.