Evaluating the sustainability of diets–combining environmental and nutritional aspects. Issue 47 (March 2015)

• Record Type: Journal Article
• Authors: Röös, Elin; Karlsson, Hanna; Witthöft, Cornelia; Sundberg, Cecilia
• Is Part Of: Environmental science & policy. Issue 47(2015:Mar.)
• Page Start: 157
• Page End: 166
• Publication Date: 2015-03
• Subjects: Sustainable diets -- Climate -- Land use -- Biodiversity -- Nutrient density score -- Nutrition; Environmental policy -- Periodicals; Environmental sciences -- Periodicals; Environnement -- Politique gouvernementale -- Périodiques; Sciences de l'environnement -- Périodiques; Environmental policy; Environmental sciences; Periodicals; Electronic journals; 363.70561
• DOI: 10.1016/j.envsci.2014.12.001
• Languages: English
• ISSNs: 1462-9011

Abstract

Highlights: Joint assessment of environmental impact and nutritional quality of diets. Three different diets were evaluated using two different methods. One method normalised environmental impact to sustainable levels. One method calculated impacts in relation to the diets' nutrient density scores. All diets assessed were above the sustainable level of climate impact. Abstract: This study examined two methods for jointly considering the environmental impact and nutritional quality of diets, which is necessary when designing policy instruments promoting sustainable food systems. Both methods included energy content and 18 macro- and micronutrients in the diet, the climate impact, land use and biodiversity damage potential. In Method 1, the content of different nutrients in the diet was normalised based on recommended intake or upper levels for average daily intake and presented together with the environmental impacts, which were normalised according to estimated sustainable levels. In Method 2, the nutritional quality of different diets was considered by calculating their nutrient density score, and the environmental impact was then expressed per nutrient density score. Three diets were assessed; a diet corresponding to Nordic recommendations, the current average Swedish diet and a lifestyle Low Carbohydrate-High Fat (LCHF) diet. Method 1 clearly showed that the climate impact was far beyond the sustainable level for all diets, while land use was within the sustainability limit for the recommended diet, but not the other two. Comparisons based on nutrient density scores depended on the score used, but the current and LCHF diets had more impact than the recommended diet (less livestock products) for all but one score. Over- and under-consumption of nutrients were clearly shown by Method 1 but not possible to distinguish with Method 2, as normalisation was not possible, making it difficult to evaluate the absolute scale of the impacts when nutrient density scores were used. For quantitative information on the environmental and nutritional impacts of diets as support in decision-making processes, it is important that data presentation is transparent. There is limited value in reducing results to a low number of indicators that are easy to read, but difficult to interpret, e.g. nutrient density score. Method 1 allows combined assessment of diets regarding environmental impact and nutritional intake and could be useful in dietary planning and in development of dietary recommendations and other policy instruments to achieve more sustainable food systems.