[1] Vrije Univ Amsterdam, Amsterdam UMC, Amsterdam Publ Hlth, Dept Publ & Occupat Hlth, Boelelaan 1117, NL-1081 HV Amsterdam, Netherlands
[2] Open Univ Netherlands, Welten Inst, Res Ctr Learning Teaching & Technol, NL-6419 AT Heerlen, Netherlands
[3] Maastricht Univ, Fac Hlth Med & Life Sci, Sch Nutr Toxicol & Metab, Dept Complex Genet, NL-6200 MD Maastricht, Netherlands