Competing interests: We have read and understood BMJ policy on declaration of interests and declare the following: AA: has received financial support from Danish Dairy Foundation, Global Dairy Platform, Arla Foods Amba, Denmark, and European Milk Foundation for projects conducted at the University of Copenhagen exploring the effects of dairy fats and cheese consumption on human health. The European Milk Foundation (EMF) sponsored the Expert Symposium on the Dairy Matrix 2016, organised by AA and co-chaired by AA and IG. AA has received travel expenses and honorariums in connection with meetings and lectures from Danone, Arla Foods, EMF, and Global Dairy Platform. HCSB: through employment at Aarhus University, has received financial support for research activities from Arla Foods amba, the Danish Dairy Research Foundation, and Arla Food for Health (a consortium between Arla Foods amba, Arla Foods Ingredients Group P/S, Aarhus University and University of Copenhagen). J-PB: None. LCPdeG: None. MCdeOO: None. ELF: has received research funding from Food for Health Ireland, a dairy technology centre part financed by Enterprise Ireland and partly by dairy companies in Ireland. ELF has received speaking expenses from the National Dairy Council and the European Milk Forum. MLG: None. IG: Estonian BioCompetance Centre of Healthy Dairy Products, consultant to the Dairy Council on fats in dairy products and cardiometabolic disease; have received travel expenses and honorariums in connection with meetings and lectures from the Dairy Council, Dutch Dairy Association, Global Dairy Platform and the International Dairy Federation. FJK: None. RMK: Grant funding from Almond Board of California and Dairy Management. BL: chair of nutrition at Laval University, which is supported by private endowments from Pfizer, La Banque Royale du Canada, and Provigo-Loblaws. None of these organisations are involved in the research conducted by BL and his team. BL has received funding in the past five years from the Canadian Institutes for Health Research, the Natural Sciences and Engineering Research Council of Canada, Agriculture and Agri-Food Canada (Growing Forward programme supported by the Dairy Farmers of Canada, Canola Council of Canada, Flax Council of Canada, Dow Agrosciences), Dairy Research Institute, Dairy Australia, Merck Frosst, and Atrium Innovations. All support is investigator initiated, with no influence of the organisations in defining the research questions, in the process related to data analysis and interpretation, and publication of results. J-ML: Works for the Centre National Interprofessionnel de l’Économie Laitière (CNIEL), Yoplait, Syndifrais, Lactalis Alliance 4, LESAFFRE, member of scientific advisory board of Agence pour la Recherche et l’Information en Fruits et Légumes, European Natural Soyfoods Association, Fédération Française des Industriels Charcutiers Traiteurs, Observatoire CNIEL des Habitudes Alimentaires, Institut Olga Triballat. PL: None. MM: Receipt of honorarium and travel expenses for presentations given at conferences organised by the Dairy Council for Northern Ireland and the European Milk Forum. RM: reports grants from NIH/NHLBI R01 HL130735, the Bill and Melinda Gates Foundation, and from Unilever, and personal fees from World Bank, outside the submitted work. M-CM: Paid consultancies for CNIEL (French Dairy Interbranch Sector) and for different food and dairy companies, research laboratory received funding from CNIEL (French Dairy Interbranch Sector), Sodiaal-Candia R&D, Nutricia Research, Danone Research, and is co-supervisor of a PhD student seconded from Institut des Corps Gras (ITERG). Member of the scientific committee of ITERG (non-financial interest). DM: Research funding from the National Institutes of Health and the Gates Foundation; personal fees from GOED, Nutrition Impact, Pollock Communications, Bunge, Indigo Agriculture, Amarin, Acasti Pharma, Cleveland Clinic Foundation, America’s Test Kitchen, and Danone; scientific advisory board, Elysium Health (with stock options), Omada Health, and DayTwo; and chapter royalties from UpToDate; all outside the submitted work. SSS-M: received funding from the Global Dairy Platform, Dairy Research Institute and Dairy Australia for a meta-analysis on cheese and blood lipids (2012) and a meta-analysis of dairy and mortality (2015). She received The Wiebe Visser International Dairy Nutrition Prize from the Dutch Dairy Association’s (NZO) Utrecht Group. In 2017, a student’s internship project was partly funded by the Dutch Dairy Organisation and Global Dairy Platform.