Kyklos Kyklos Peer Effects on Weight Status, Dietary Behaviour and Physical Activity among Adolescents in Europe: Findings from the I.Family Study Gwozdz W. Nie P. Sousa-Poza A. DeHenauw S. Felso R. Hebestreit A. Iguacel I. Universidad de Zaragoza Lissner L. Lauria F. Page A. Reisch L.A. Tornaritis M. Veidebaum T. Williams G. Foraita R. 2019 research-article