The main objective of this paper is to describe the process of the inclusion of sustainability in the Italian Dietary Guidelines (IDGs). In the IDGs’ sustainability chapter, particular emphasis was put on the selection of foods, recommending a plant-based diet with a large quota of vegetable proteins. Advice was also given on the selection of local seasonal products, with low growth input, such as fertilizers, artificial light and heating. Reduction of animal food was recommended, to be substituted with lower impact foods (poultry, milk, eggs and Mediterranean fish including aquaculture). Food waste was largely addressed. Recommendations were made for food purchase planning, food storage and the reuse of leftovers as strategies to reduce waste and save money. The IDGs sustainability recommendations were related to the 16 guiding principles of a sustainable healthy diet and their contribution to the achievement of the Sustainable Developing Goals was provided. The inclusion of sustainability in dietary guidelines requires a multidisciplinary approach to cover the wide range of aspects of a sustainable diet. In the IDGs, it was possible to show that practical recommendations for improving sustainability behavior can be passed on to consumers. Methodological aspects for developing recommendations are not definitive.