This work contributes to the urban agriculture field of investigation in one aspect that remains lightly explored: the coupling of material and social dimensions in urban metabolisms studies. This paper offers an urban metabolism path investigation, which aims at confronting the flows of organic waste, the practices of the city-dwellers and the strategies of public bodies. We've applied the "metabolic rift" theoretical framework, established by McClintock (2010), to explore the ecological, social and individual dimensions of organic waste management in Rennes Metropolitan Area (France). In this way, the trajectory of the Rennes Metropolitan waste programs, the material flow analysis of biomass, and the study of inhabitants' composting practices have allowed us apprehending the metabolic rift between its social dimension (the decommodification of land, food, and labor), its ecological dimension (short-loop recycling by distributing compost to participants or other users), and its individual dimension (de-alienation from nature). The strengths and weaknesses relating to these three dimensions are then discussed to bring out some opportunities and threats.