Today, various types of fair trade systems propose new forms of relationships between producers and consumers. If several studies have provided accurate understandings of consumers' motivations to buy fair trade products, the specific kinds of consumer involvement that are emphasized in those systems remain partly unknown. In France, controversies about the regulation and organization of fair trade with producers from Southern countries has led to broader debates about how consumers can best express their solidarity with producers. In these debates local food networks are often portrayed as good examples of fair trade and as having potential to redefine the role of the consumer in the marketplace (or in commercial relations). Based on examination of the type of mechanisms used to enrol consumers in local and fair trade networks, we have distinguished two main kinds of consumers' involvement. The first one may be called "delegation" and is based on market mechanisms. The second one is called "empowerment" and is based on contractual mechanisms between consumers and producers and on the construction of collective choices. This latter kind of consumer involvement points out the capacity of alternative food networks to empower consumers in a more broadly political sense.