FISH IN THE DIET FISH provides another class of high-protein or tissue-building food. As this term is generally understood, it includes both vertebrate fish that is, fish having a backbone such as salmon, cod, shad etc. and many other water animals such as lobsters, crabs, shrimp, oysters and clams. Fish can usually be purchased at a lower price than many other food items and for this reason possesses an economic advantage over them. Some varieties of fish are sought more than others, the popularity of certain kinds depending on the individual taste or the preference of the people in a particular locality. As is well known, fish is an extremely perishable food. Therefore, when it is caught in quantities too great to be used at one time, it is preserved in various ways. The preservation methods that have proved to be the most satisfactory are canning, salting and drying, smoking and preserving in various kinds of brine and pickle. As such methods are usually carried out in the locality where the fish is caught, many varieties of fish can be conveniently stored for long periods of time and so distributed as to meet the requirements of the consumer. This plan enables persons far removed from the Source of supply to procure fish frequently.
COMPOSITION AND CLASSES OF FISH In general, the composition of fish is similar to that of meat, for both of them are high-protein foods. However, some varieties of fish contain large quantities of fat and others contain very little of this substance, so the food value of the different kinds varies greatly. As in the case of meat, fish is lacking in carbohydrate. Because of the close similarity between these two foods, fish is a very desirable substitute for meat. In fish, as well as in shell fish, a very large proportion of the food substances present is protein. This proportion varies with the quantity of water, bone, and refuse that the particular food contains, and with the physical structure of the food. The percentage of fat in fish varies from less than 1 per cent in some cases to a trifle more than 14 per cent in others.
