To date, biological indicators used to assess river health are mainly based on assemblage structure (species composition), and poorly incorporate the functional features of ecosystems. Food webs, as networks of species linked by trophic interactions, integrate both structural (via the species) and functional (via the interactions) features of ecosystems. We propose to take advantage of this duality for assessing the “ecological status” of rivers in a more comprehensive way. In our project we address this issue by developing isotopic metrics of food webs, and examining their suitability to assess river health. For that, we described the food webs of 57 French streams analysing carbon and nitrogen stable isotopes of organic matter sources, macroinvertebrates and fish. We calculated the food web metrics and examined their responses to three environmental factors (fluvial gradient, geology and climate) under low and high anthropogenic pressures (related to river morphology and/or organic pollution). The project aims at giving a representative picture of the stream food webs of France, and at selecting the metrics displaying the highest sensitivity to human pressures in a monitoring perspective. Preliminary results let us think that food web metrics constitute a highly promising area of research to assess river health.