This systematic review evaluates the environmental impact of 49 dietary scenarios and shows that shifts in consumption could reduce diet-related GHG emissions and land use demand by up to 50%. The paper states that the amount and type of meat in the diet mainly affects the improvement potential. The research also identifies and addresses research gaps and key methodological aspects influencing outcomes.
Global food production is identified as a great threat to the environment. In combination with technical advances in agriculture, dietary change is suggested to be necessary to reduce the environmental impact of the food system. In this article a systematic review assessing the environmental impact of dietary change is performed. The aims are to i) evaluate the scientific basis of dietary scenario analysis, ii) estimate the potential environmental effects of dietary change, iii) identify methodological aspects of importance for outcome and iv) identify current gaps in knowledge. The review includes 14 peer-reviewed journal articles assessing the GHG emissions and land use demand of in total 49 dietary scenarios. The results suggest that dietary change, in areas with affluent diet, could play an important role in reaching environmental goals, with up to 50% potential to reduce GHG emissions and land use demand associated with the current diet. The choice of functional unit, system boundaries and methods for scenario development and accounting for uncertainties are methodological aspects identified to have major influence on the quality and results of dietary scenario analysis. Further understanding of dietary change as a measure for more sustainable food systems requires improved knowledge of uncertainty in dietary scenario studies, environmental impact from substitutes and complements to meat and the effect of dietary change in different groups of populations and geographical locations.
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