1 Medical Research Council (MRC) Unit, Banjul, The Gambia; MRC International Nutrition Group, London School of Hygiene and Tropical Medicine, London, United Kingdom; andrew.prentice@lshtm.ac.uk.
2 Medical Research Council (MRC) Unit, Banjul, The Gambia; MRC International Nutrition Group, London School of Hygiene and Tropical Medicine, London, United Kingdom;
3 Department of Child Life and Health, University of Edinburgh, Edinburgh, United Kingdom; and.
4 MRC Human Nutrition Research, Elsie Widdowson Laboratory, Cambridge, United Kingdom.