The International Life Sciences Institute (ILSI) is pleased to bring you the 7th edition of Present Knowledge in Nutrition, a well-respected, authoritative source for the state-of-knowledge in nutrition. This publication, which has been published continuously for over 50 years, is a key reference used for instructing nutritional professionals. Given that nutrition is a key factor in improving public health worldwide, which is ILSI's mission, this publication is a useful tool in accomplishing this mission. The chapter authors were selected for their knowledge, experience, and ability to transmit knowledge effectively. The field is expanding rapidly, so the publication has also expanded to a new two-volume format that is easy to read and digest.