Study protocol of a population-based cohort investigating Physical Activity, Sedentarism, lifestyles and Obesity in Spanish youth: the PASOS study oleh Susana Aznar, Camille Lassale, Santiago Felipe Gómez, Clara Homs, Julia Wärnberg, Maria Medrano, Marcela Gonzalez-Gross, Narcis Gusi, Elena Marín Cascales, Miguel González-Valeiro, Lluis Serra-Majem, Nicolás Terrados, Josep A Tur, Marta Segú, Juan Carlos Benavente-Marín, Idoia Labayen, Augusto García Zapico, Jesús Sánchez-Gómez, Fabio Jiménez-Zazo, Pedro Emilio Alcaraz, Marta Sevilla-Sanchez, Estefania Herrera-Ramos, Susana Pulgar, Maria del Mar Bibiloni, Olga Sancho, Helmut Schröder