Alternative food networks (AFNs) have emerged to improve both environmental and socio-economic aspects of food provisioning, including the living and working conditions of farmers. Their objectives are supposed to be mediated through the shortening of chains and/or the implication of alternative value chain actors (VCAs). Through the application of a social life cycle assessment methodological proposal on two products from three Belgian AFNs, we first verify how the AFNs meet sustainability promises. Second, we investigate how such social sustainability of the assessed products is influenced by the differentiated configurations of chain governance in the AFNs. Such a discussion of root causes of social sustainability performances in product chains have been investigated very little as of yet. Our results show that AFN perform well in some aspects (consumer aspects, work satisfaction, social ties between VCAs), but in some others, AFN chains use similar mechanisms as the ones used by mainstream chains (unbalanced market power, unfair prices, and low commitment between VCAs), with potentially detrimental effects on profitability and employment conditions for VCAs located upstream, i.e., farms. Our framework is useful to highlight social hotspots in product chains, and to discuss these across the differences in the configurations of the chain layout and—in the end—chain governance.