Improving Health And Carbon Footprints Of European Diets Using A Benchmarking Approach

Objective: This study aimed to identify diets with improved nutrient quality and environmental impact within the boundaries of dietary practices.Design: We used Data Envelopment Analysis to benchmark diets for improved adherence to food-based dietary guidelines (FBDG). We then optimised these diets for dietary preferences, nutrient quality and environmental impact. Diets were evaluated using the Nutrient Rich Diet score (NRD15.3), diet-related greenhouse gas emission (GHGE) and a diet similarity index that quantified the proportion of food intake that remained similar as compared with the observed diet.Setting: National dietary surveys of four European countries (Denmark, Czech Republic, Italy and France).Subjects: Approximately 6500 adults, aged 18-64 years.Results: When dietary preferences were prioritised, NRD15.3 was similar to 6 % higher, GHGE was similar to 4 % lower and similar to 85 % of food intake remained similar. This diet had higher amounts of fruit, vegetables and whole grains than the observed diet. When nutrient quality was prioritised, NRD15.3 was similar to 16 % higher, GHGE was similar to 3 % lower and similar to 72 % of food intake remained similar. This diet had higher amounts of legumes and fish and lower amounts of sweetened and alcoholic beverages. Finally, when environmental impact was prioritised, NRD15.3 was similar to 9 % higher, GHGE was similar to 21 % lower and similar to 73 % of food intake remained similar. In this diet, red and processed meat partly shifted to either eggs, poultry, fish or dairy.Conclusions: Benchmark modelling can generate diets with improved adherence to FBDG within the boundaries of dietary practices, but fully maximising health and minimising GHGE cannot be achieved simultaneously.