With the publication of this book, researchers from the HELENA (funded under the 6th Framework Programme) Consortium, put at the disposal of the scientific community a rigorous work to obtain epidemiological data on dietary intake, lifestyle (physical activity, sedentary lifestyle, eating behaviour), body composition, physical condition, biological samples (blood, saliva) in the context of a European multicenter project. 18 chapters and annexes, introduces the documentary basis of the methodology, questionnaires and sheet records in nine languages.