[1] Univ Cambridge, Sch Clin Med, Dept Publ Hlth & Primary Care, Cambridge, England
[2] Univ Cambridge, MRC Human Nutr Res, Cambridge, England
[3] Pfizer Worldwide Res & Dev, Computat Sci Ctr Emphasis, Cambridge, MA USA
[4] Univ Penn, Perelman Sch Med, Dept Biostat & Epidemiol, Philadelphia, PA 19104 USA