The effect of dietary macronutrients on the food intake of juvenile gilthead seabream, Sparus aurata (L.), was examined in two experiments. In the first experiment, fish (68.14 plus minus 12 g) were randomly assigned to two outdoor tanks (30 fish/tank) and fed to satiation twice daily (9:00 and 21:00) for 30 days on one of the two diets with similar gross energy content. In the second experiment, four groups of fish (67.19 plus minus 13 g) were randomly assigned to four outdoor tanks (30 fish/tank). Each group was fed to satiation twice daily (9:00 and 16:00) for 4 weeks on one of the four experimental diets with varying macronutrient contents, and using the Latin square design (4 weeks x 4 diets x 4 groups). Both experiments suggest that protein is the controlling factor regulating food intake in gilthead seabream.