What Contributes to the Variation of Dairy Recommendations in Global Food-Based Dietary Guidelines

Abstract

ObjectivesDairy consumption remains controversial due to uncertainty about its health impacts and effects on food sustainability. There are variations in dairy recommendations in global food-based dietary guidelines (FBDGs). Yet, how methods used to develop recommendations contribute to such variation is unknown. In this study, we assessed this dietary context in dairy recommendations. MethodsWe search the FBDG database at the Food and Agricultural Organization website in 2019 to identify dietary guidelines published since 2009. Eligible guidelines needed to include dietary recommendations and describe the guideline development processes. Protocols for this review were registered (CRD42019125258; CRD42019126452) and published previously. Two reviewers independently reviewed the guidelines and extracted information on dairy recommendations. Systematic review methods, quality of evidence assessment, evidence underpinning the recommendations, and information on health equity were evaluated. We used descriptive statistics to summarize the findings. ResultsWe included 26 eligible FBDGs, including the Dietary Guidelines for Americans 2020–2025. Serving sizes of dairy recommendations varied, ranging from 1 ser/d (11.5%) to 3–5 ser/d (3.9%), with 27% of the guidelines recommending 2 ser/d and another 27% having no or unclear recommendations. The majority of the guidelines (n = 19, 73%) endorsed low-fat or skimmed fat dairy, while 7 (27%) did not emphasize fat contents. All guidelines recommended dairy as a dietary source for calcium (n = 16, 61.5%) and/or vitamin D (n = 10, 38.5%). Only 8 guidelines (31%) recommended dairy alternatives, among which 4 (18%) recommended soy products. Systematic review methods and evidence quality assessment were implemented in 5 guidelines (19%). Only 12 guidelines (46%) considered health equity to address cultural/regional aspects to formulate dietary recommendations. ConclusionsMost dietary guidelines recommend reduced-fat dairy consumption, but only 31% recommend plant-based protein as dairy alternatives, despite lactose intolerance and food sustainability as global concerns. Methodological rigor in the evidence base and health equity considerations remain a challenge in dietary guideline development. Funding SourcesThe Australian National Health and Medical Research Council.