Annex 2: Methodological references of HELENA-CSS in relation with this paper

• Moreno LA, De Henauw S, González-Gross M et al. Design and implementation of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study. Int J Obes (Lond) 2008; 32 (Suppl. )5: S4-11.

• Moreno LA, González-Gross M, Kersting M et al. Assessing, understanding and modifying nutritional status, eating habits and physical activity in European adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study. Public Health Nutr 2008; 11: 288-99.

• Ortega FB, Artero EG, Ruiz JR et al. Physical fitness levels among European adolescents: The HELENA study. Br J Sports Med 2009.

• Ortega FB, Artero EG, Ruiz JR et al. Reliability of health-related physical fitness tests in European adolescents. The HELENA Study. Int J Obes (Lond) 2008; 32 (Suppl. 5): S49-57.

• Beghin L, Castera M, Manios Y et al. Quality assurance of ethical issues and regulatory aspects relating to good clinical practices in the HELENA Cross-Sectional Study. Int J Obes (Lond) 2008; 32 (Suppl. 5): S12-8.

• Ruiz JR, Ortega FB, Gutiérrez A et al. Healthrelated fitness assessment in childhood and adolescence: a European approach based on the AVENA, EYHS and HELENA studies. J Public Health 2006; 14: 269-77.