Claus Leitzmann, born in 1933, studied chemistry, microbiology and biochemistry in the US. Fellow researcher of the Nobel laureate Paul Boyer at UCLA. Five years of teaching and research in Bangkok and Chiang Mai, Thailand. Since 1974 at the Institute of Nutrition at the University of Giessen. Habilitation 1976. From 1978 until 1998 professor of nutrition in developing countries. 30 books on various aspects of nutrition, numerous volunteer activities and several awards. Areas of Focus: International Nutrition; Wholefood Diet; Vegetarianism; Foraging Ecology; Nutrition Education.