The world’s oceans can no longer sustain the ever-rising demand for fish. Aquaculture offers an alternative approach – if production is sustainable and high quality. INRAE, the Aqualande group and its selective breeding company Les Sources de l’Avance, and the French Poultry and Aquaculture Breeders Technical Center (SYSAAF) reviewed data from 20 years of a rainbow trout breeding programme conducted by the company. They compared the growth and nutrition needs of trout from this programme with those of an unselected trout population. Their findings, published in Aquaculture Reports, show that selected trout need 17% to 20% less feed to achieve the same growth as the unselected ones. As a result, the environmental impacts of fish farming can be reduced. A locally produced feed, made without fish oil, fishmeal or soy, was also tested on both groups of fish. The fish fed this “future” feed, which has similar nutritional characteristics, achieved similar growth performance. These unique results show that selective breeding and innovative feed sources can be effectively combined to make aquaculture more sustainable.