The present study part of the the European Prospective Investigation into Cancer and Nutrition (EPIC) - Heidelberg, a large-scale observational cohort study located at the German Cancer Research Center, Heidelberg, Germany. The study started between 1994 and 1998, when 25 540 adults from the local general population were recruited. Study participants are being followed-up by active and passive procedures. The main aim of the study is to evaluate associations between diet, lifestyle as well as metabolism and risks of major chronic diseases (cancer, cardiovascular diseases, diabetes).