Most fish are very particular feeders and require a high quality diet that is adapted to their stage in life. A young fish has quite a different dietary requirement to an adult one. They are fed using nutrient-dense, dry feed pellets. Different types of feeds, mainly distinguished by variations in pellet size, fat and protein content, are fed according to the life stage of the fish.

The feeds have been developed to meet the nutritional requirements of healthy growing fish and contain a variety of ingredients, with fish meal and fish oil being the major ones. They also include vitamins, essential micronutrients and vegetable proteins and cereals. The latter serve also to bind the feed together so that it does not disperse quickly in water.

No growth hormones are used in professional aquaculture in Europe. .