Reduced meat and dairy consumption improves health, environmental and most nutritional outcomes without increasing diet costs among Scottish adults.

Shifting diets away from high levels of meat and dairy is increasingly considered an important part of climate mitigation, yet the best pathways for achieving these reductions without compromising nutrition, health or affordability remain unclear. Here, in a representative sample of Scottish adults, we evaluate 33 pathways to meeting the UK Climate Change Committee's recommendations to reduce meat and dairy consumption by 20% by 2030, increasing to a 35% reduction in meat by 2050. The pathways incorporate existing dietary guidance, and modelled outcomes include intakes of 54 nutrients, obesity, type 2 diabetes, cardiovascular disease, all-cause mortality, diet costs, greenhouse gas emissions, freshwater use, land use and eutrophication. Nearly all pathways were estimated to benefit most nutritional, health and environmental outcomes without increasing diet costs. Benefits were greater when reductions targeted high consumers of red meat and when meat and dairy were replaced gram for gram with foods such as vegetables, beans, eggs and plant-based dairy alternatives.