Poor diet is a leading risk for non-communicable diseases, but adherence to food-based dietary guidelines in Europe is low. In addition, our current diet has a major impact on the environment. There is thus an urgent need to improve the diets for European consumers. This thesis shows and evaluates possible solutions for improved diets using a benchmarking diet model. The great advantage of this model is that it implicitly incorporates dietary preferences of consumers by making use of existing diets. Within the ranges of observed dietary practices, results show that consumers may improve their nutrient quality up to 16% and reduce their diet-related greenhouse gas emissions up to 20%. However, to simultaneously achieve these improvements, dietary preferences need to be inspired by the rich diversity of European diets and complementary changes in the food supply chain are needed.