Foods that are high in water and low in fat-such as fruits, vegetables soup, lean meat, and low fat dairy pro low in calorie density and v provide few calories per bite. "Eating a diet that is low in calorie density allows people to eat satisfying portions of food, and this may decrease feelings of hunger and deprivation while reducing Dr. Julia calories," said A. Ello-Martin, who conducted the study as part of her doctoral dissertation in the College of Health and Human Development at Penn State. Previously, little was known about the influence of diets low in calorie density on body weight. "Such diets are known to reduce the intake of calories in the short term, but their role in promoting weight loss over the 15 long term was not clear," said Dr. Barbara J. Rolls, who directed the study and who holds the Helen A. Guthrie Chair of Nutritional Sciences at Penn State.