More sustainable food choices are part of a complex system that combines practices, which themselves are interconnected in a network of elements made up of competences, meanings and material devices. This article proposes an innovative method for studying this system through a non-deductive quantitative approach. The research adds to the corpus of the ‘theory of practices’ by defining the concepts of ‘central’ practices (i.e. connected to many elements of the system, such as the practice of buying and cooking sustainable products in the sustainable food system) and ‘peripheral’ practices (i.e. connected in a lesser extent to other elements of the system, such as the practices of anti-waste, growing your own food and the consumption of plant proteins). It also highlights the ‘connector’ role between the practices of certain elements. Finally, based on the current structure of the system of sustainable food practices, the article makes several propositions for speeding up change.