The association between obesity and severe disability among adults aged 50 or over in nine high-income, middle-income and low-income countries : a cross-sectional study - Koyanagi, Ai (Centro de Investigación Biomédica en Red de Salud Mental) ; Moneta, Maria Victoria (Centro de Investigación Biomédica en Red de Salud Mental) ; Garin, Noe (Institut d'Investigació Biomèdica Sant Pau) ; Olaya, Beatriz (Centro de Investigación Biomédica en Red de Salud Mental) ; Ayuso-Mateos, Jose Luis (Instituto de Investigación Hospital Universitario de la Princesa) ; Chatterji, Somnath (Department of Health Statistics and Information Systems, World Health Organization, Geneva, Switzerland) ; Leonardi, Matilde (Neurological Institute Carlo Besta IRCCS (Milà, Itàlia). Department of Neurology, Public Health and Disability Unit) ; Sainio, Päivi (National Institute for Health and Welfare, Helsinki, Finland) ; Galas, Aleksander (Department of Epidemiology, Jagiellonian University Medical College, Krakow, Poland) ; Haro Abad, Josep Maria (Centro de Investigación Biomédica en Red de Salud Mental) ; Universitat Autònoma de Barcelona