Shifting towards more plant-based diets can reduce the environmental burden of the food system including its impact on the nitrogen cycle. However, such changes need to be compatible with healthy nutrition. To discuss the health aspects of plant-based dietary patterns, this literature review analyses vegetarian and vegan diets and concludes that well-planned, balanced vegetarian diets are nutritious and healthy. Food-based dietary guidelines (FBDGs) that include environmental aspects and practical advice to individuals and society are needed as crucial instruments to further promote public health within the planetary boundaries. FBDGs need to be better exploited to serve as a basis to policies that promote diets supporting the UN sustainable development goals.