The protein content of fish varies, but it generally amounts to 15 to 20 percent of the tissue. Water and fat account for most of the remaining 80 to 85 percent. Fat content varies greatly among species and fluctuates seasonally within species. Fat content depends on the season and on the fish's size, age, and sex. It tends to be higher during warmer months, when food is more plentiful.
Fish provides important nutrients for the human diet.
Fish protein is a complete protein that contains all the essential amino acids. It is also easily digested. The fat in fish is highly unsaturated, and research has shown that this type of fat can be associated with a reduced risk of coronary disease. Most fish have a low sodium content, and most species can be used in low-sodium diets. Caught Changes take place in a fish after it is caught because of its biological composition and its environment.