Crab is one of the best possible dietary sources of protein available. It contains almost as much protein per 100 grammes as meats without anywhere near the same levels of saturated fat, which is linked to an increased risk of heart disease.
Fish is a high-protein, low-fat food that provides a range of health benefits. White-fleshed fish, in particular, is lower in fat than any other source of animal protein, and oily fish are high in omega-3 fatty acids, or the "good" fats.
Chicken is not only a good source of protein, very rich in vitamins and minerals. For example, B vitamins are useful in preventing cataracts and skin disorders, as well as preventing migraine, heart disorders, gray hair, high cholesterol, and diabetes.