AMES, Iowa (AP) — A new Iowa State University study shows your mother was right when she told you to chew your food thoroughly. James Hollis, an Iowa State assistant professor of food science and human nutrition, says chewing food 40 times before swallowing reduces food intake by boosting the feeling of fullness and improves nutrient absorption. He studied 20 ISU students who were given pizza. Half chewed each bite 15 times and the other half 40 times. Researchers monitored the subjects’ appetite and took blood samples to study plasma glucose levels and hormones. Those who chewed more ate less. The study results will be presented this weekend at an experimental biology conference in San Diego, Calif.