Robert H. Lustig is an American pediatric endocrinologist at the University of California, San Francisco (UCSF) where he is a professor of clinical pediatrics. He practices in the field of neuroendocrinology, with an emphasis on the regulation of energy balance by the central nervous system. He also has a special interest in childhood obesity. Lustig came to public attention through his efforts to establish that fructose can have serious deleterious effects on human (especially children's) health if consumed in excessive amounts.
Bio from Wikipedia.