This data set contains the results from a nutritional trial performed at the Centre of Marine Sciences of Algarve (CCMAR, Faro, Portugal) within the framework of WP2 of the MedAID project (Mediterranean Aquaculture Integrated Development, Horizon 2020, GA number 727315). This experiment evaluated the impacts of protein to lipid ratios in low fishmeal/fish oil diets on key performance indicators of gilthead seabream (Sparus aurata, initial weight: 100 g ± 7 g) on-grown during summer temperature conditions. For further information on experimental conditions, please refer to the publication: “Aragão C., Cabano M., Colen R., Teodósio R., Gisbert E., Dias J. and Engrola S., 2022. Modulation of dietary protein to lipid ratios for gilthead seabream on-growing during summer temperature conditions. Aquaculture Reports, 25: 101262. doi:10.1016/j.aqrep.2022.101262”. In addition to properly cite this dataset, it would be appreciated that when using this dataset in a publication the original publication is cited.