Competing interests: We have read and understood BMJ policy on declaration of interests and declare the following: DM receives research support from the National Institutes of Health and the Gates Foundation. DM has received personal fees from Acasti Pharma, GOED, DSM, Nutrition Impact, Pollock Communications, Bunge, and Indigo Agriculture; scientific advisory board, Omada Health and Elysium Health; and chapter royalties from UpToDate; all outside the submitted work. He receives support from National Heart, Lung, and Blood Institute. NGF receives support from the Medical Research Council.