[1] Univ Bristol, NIHR, Bristol Biomed Res Ctr BRC Nutr Theme, Bristol, Avon, England
[2] Univ Bristol, Bristol Med Sch Populat Hlth Sci, Bristol, Avon, England
[3] Univ Bristol, Dept Maxillofacial Surg, Bristol, Avon, England
[4] Univ Bristol, Sch Social & Community Med, Dept Randomised Trials Collaborat, Bristol, Avon, England