Sustainability assessment of diets-environmental and health aspects

• Food choices affect both the environment and health. When assessing the sustainability of diets both these aspects need to be considered. Health impacts as a consequence of dietary habits and environmental impacts from food production occur at different stages of the food chain. The present interdisciplinary study presents a detailed evaluation of health effects from dietary habits and an environmental assessment, linking food intake and primary production. The aim was to develop a model for evaluating whole diets from both environmental and health perspectives. In a case study this model was used to compare three Swedish diets: the Swedish Nutrition Recommendations Objectified (SNO) as the recommended diet from the Swedish National Food Agency, the habitual diet of the Swedish population as assessed in the national food consumption survey “Riksmaten 2010-11” and a Low Carbohydrate High Fat (LCHF) diet which is popular but under debate regarding environmental sustainability and effects on health. The food production required for the intake of a specified amount of each food item was estimated using published factors for waste in the food chain and weight losses during cooking and preparation of foods. Three environmental impact categories were included: global warming potential, land use and land use biodiversity damage potential (BDP). Data was gathered from previous LCA studies for global warming potential and land use. Land use and its location were determined from statistics on yield and trade. BDP from land use was assessed applying the method developed by de Baan et al. (Int J Life Cycle Assess 2012). The number of primary products included was limited to 50, due to the level of detail in food intake statistics and the availability of LCA data and yield statistics. The health impact of the diets was determined by evaluating the intake of energy, macro- and micronutrient for compliance with Nordic Nutrition Recommendations 2004. For the LCHF diet a land use of around 0.44 ha land per capita was required, substantially higher than the current Riksmaten diet with 0.33 ha and the recommended SNO diet with 0.25 ha. For all diets, around 60% of the land use was located in Sweden and around 30% in Europe. The LCHF diet had a Global warming potential of 2.3 ton CO2-eq per capita and year compared to the Riksmaten and SNO diets with 1.7 and 1.4 CO2-eq, respectively. Biodiversity damage potential (BDP) was dependent on area occupied, therefore the LCHF diet with the highest land use had the highest BDP. The recommended SNO diet showed, as expected, compliance with dietary recommendations for all micro- and macronutrients, demonstrating that the new model is valid. The other two diets Riksmaten and LCHF resulted in too high intakes for particular nutrients, e.g. saturated fatty acids and cholesterol, and in a too low intake for e.g. fiber, which is detrimental for sustaining health potentially promoting e.g. cardiovascular diseases and cancer. Summarizing, the new model allows for a simultaneous evaluation of diets from environmental and health perspectives. It provides a tool for estimating health and environmental impact when modulating diets according to either national public health or environmental targets.

Ämnesord

LANTBRUKSVETENSKAPER  -- Annan lantbruksvetenskap -- Miljö- och naturvårdsvetenskap (hsv//swe)

AGRICULTURAL SCIENCES  -- Other Agricultural Sciences -- Environmental Sciences related to Agriculture and Land-use (hsv//eng)

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