Region-specific and nutritionally adequate dietary transitions can bolster sustainability and socioeconomic benefits

Shifting towards plant-based diets and reducing ruminant-based food consumption offers broad benefits but varies across regions. Here we use an integrated assessment model to explore sustainable dietary transitions under diverse consumers, behavioural adoption and regional uncertainties. Increasing plant protein intake or lowering ruminant reliance can support nutritionally adequate diets while improving calorie intake. These dietary shifts also reduce greenhouse gas emissions, air pollution-related mortality, water scarcity and food expenditure. In addition, they promote re/afforestation, biodiversity and lower mitigation costs under Nationally Determined Contributions and Long-Term Targets climate policies. Regional strategies prove more effective than uniform global targets. Our results highlight the importance of supportive policies to enable dietary change, demonstrating the dual public health and environmental gains of sustainable consumption patterns.