The article illustrates selected results of an exploratory research study on ‘GAS movement’ coordinated by the Solidarity Economy Network in Marche Region, Italy. The GAS experience proves to revolve substantially around food purchasing groups practice. Therefore, the research aimed at investigating the economic and eco-logical determinants characterising the world of critical food consumption. Qualitative and quantitative data have been analysed from a socio-economic and ecological point of view, providing an insight on different issues concerning the framework of the solidarity economy and possible further developments. The ecological performance of a “critical food consume” in comparison with a “conventional one” was assessed using the Material Input Per Service unit (MIPS) concept.