Transitions to sustainable consumption and production patterns now appear as a widely acknowledged necessity for contemporary food systems. Sustainable transition processes raise major issues of social justice as they often exclude some actors and social groups, as the literature on alternative food networks has amply shown. Based on three case studies anchored in different national contexts (France, Brazil and Belgium), which all emerged at the interface of civil society and public policy, the aim of this article is to show how their promoters try to tackle together sustainable transitions, food justice and food democracy, and thus make food system transitions not only sustainable but also socially just. They adopt on the one hand, an analytical stance on transitions to more sustainable food practices, on inequalities of access and on participation, and on the other hand, an experimental stance leading them to put to test specific mechanisms to support these transitions, to alleviate food injustice and to favour participation and thus also food democracy. We show that it is by combining these analytical and experimental stances that these social experiments succeed to different degrees in articulating sustainable transitions, food justice and food democracy.