However, modifying diets to favour decreased emissions, must also account for appropriate protein and nutrient intake. In this context, Henrik Saxe and colleagues evaluate the Global Warming Potential (GWP) of two healthy Nordic diets relative to the Average Danish Diet, to establish whether the New Nordic Diet (NND) is environmentally sustainable or not, and how it could be improved. Recognizing that the GWP is only one of several categories for evaluating diet-related environmental effects, the researchers calculate the GWP for food and beverages by consequential Life Cycle Assessment (cLCA), and describe the GWP of each diet according to the food items. The study revealed that the contents of the Nordic diets support climate mitigation because of lower animal-sourced material, higher vegetable and fruit content and locally and organically produced food.
The potential greenhouse gas (GHG) emissions from the production of food for three different diets are compared using consequential Life Cycle Assessment. Diet 1 is an Average Danish Diet (ADD); diet 2 is based on the Nordic Nutritional Recommendations (NNR), whilst diet 3 is a New Nordic Diet (NND) developed by the OPUS project. The NND contains locally produced Nordic foods where more than 75 % is organically produced. NNR and NND include less meat and more fruit and vegetables than the ADD. All diets were adjusted to contain a similar energy and protein content. The GHG emissions from the provision of NNR and NND were lower than for ADD, 8 % and 7 % respectively. If GHG emissions from transport (locally produced versus imported food) are also taken into account, the difference in GHG emissions between NND and ADD increases to 12 %. If the production method (organic versus conventional) is taken into account so that the ADD contains the actual ratio of organically produced food (6.6 %) and the NND contains 80 %, the GHG emissions for the NND are only 6 % less than for the ADD. When the NND was optimised to be more climate friendly, the global warming potential of the NND was 27 % lower than it was for the ADD. This was achieved by including less beef, and only including organic produce if the GHG emissions are lower than for the conventional version, or by substituting all meat with legumes, dairy products and eggs.
Saxe, Henrik, Larsen, Thomas and Mogensen, Lisbeth, (2013), The global warming potential of two healthy Nordic diets compared with the average Danish diet, Climatic Change, 116, issue 2, p. 249-262
Read the full study here. A new FCRN discussion paper addressing the question ‘What is a sustainable diet?’ will be out early next week. In the meantime you can browse our website for information on “sustainable healthy diets”.