Dietary change for sustainable food systems: Effects on climate, land use and health

Abstract: Food production and consumption are key drivers of environmental pressures and essential factors in the promotion and maintenance of health. Production of food occupies more than 1/3 of global land areas and is estimated to be responsible for some 30% of global greenhouse gas emissions. At the same time, we live in a world where nearly one billion people go hungry and even more people suffer from health problems related to overweight and obesity. This raises the question about sustainability of the current food systems.
In this thesis the potential of dietary change as a measure to reduce environmental impact and increase health is analyzed with special attention to uncertainty aspects in used data and methods. The results illustrate that awareness of the variability and uncertainty in used data and methods may be crucial for a proper use and interpretation of results in sustainability studies of food and diets. It is further suggested that dietary change, in areas with affluent diet, could play an important role in reaching environmental and health goals, with up to 50% potential to reduce GHG emissions and land use change. The potential to improve sustainability of the food system through dietary change can be substantial and mainly depends on the amount and type of meat included in the diet.
Further understanding of dietary change as measure for more sustainable food systems requires interdisciplinary and holistic assessments of the diet including more sustainability aspects. There is also need for improved knowledge of the environmental impact of substitutes and complements to meat, of the effect of dietary change in different geographical regions, of the uncertainties in dietary scenario studies and of policy instruments that can facilitate the transition towards more sustainable diets.