Lynn Parker Klees, MA, RDN, LDN, FAND was an Assistant Teaching Professor and the professor in charge of undergraduate education in the Department of Nutritional Sciences at The Pennsylvania State University when this text was created in 2019. She has taught introductory nutrition courses for undergraduates and nutrition education and counseling to both undergraduates in residence at University Park, and to graduate students in the P.S.U. World Campus Master of Professional Studies in Nutritional Sciences. Lynn has worked as a clinical dietitian and held management positions in hospitals, physician offices, and private practice. She is a registered dietitian nutritionist, certified diabetes care and education specialist, and a member and fellow of the Academy of Nutrition and Dietetics.