[1] UCL, Dept Epidemiol & Publ Hlth, Hlth Behav Res Ctr, Gower St, London WC1E 6BT, England
[2] Anglia Ruskin Univ, Cambridge Ctr Sport & Exercise Sci, Dept Life Sci, East Rd, Cambridge CB1 1PT, England
[3] UCL, UCL Inst Environm Design & Engn, Bartlett Fac Built Environm, Cent House,14 Upper Woburn Pl, London WC1H 0NN, England
[4] Glasgow Ctr Populat Hlth, Third Floor,Olympia Bldg, Glasgow G40 2QH, Lanark, Scotland
[5] UCL, UCL Bartlett Fac Built Environm, 132 Hampstead Rd, London NW1 2PS, England