Barbara Rolls, Ph.D, holds the endowed Guthrie Chair of Nutritional Sciences at Pennsylvania State University and has served on the advisory council of the NIH's National Institute of Diabetes and Digestive and Kidney Diseases.
She is the author of the "Volumetrics Weight-Control Plan," "The Volumetrics Eating Plan," and three books for health professionals on nutrition, as well as more than 200 research articles.