The word “meat” refers to all the edible parts of warm-blooded animals, which also includes internal organs, innards or entrails. In everyday language and in many regulations, the term excludes fish and fishery products, so it is actually the flesh of the fish that is referred to with the term “fish”.
According to the European Council, meat is divided into different categories according to the animal it comes from: domestic ungulates (cattle, pigs, sheep, goats, horses); poultry; rabbits, hares and rodents; game. Meat is also commonly categorised according to its colour: red meat (ox, horse, mutton and some birds like guinea fowl, goose, pigeon and duck); pink (pork and veal); and white (chicken, turkey, rabbit, lamb and goat). Meat deriving from fish is also white. The colour of a meat depends on its concentration of myoglobin, a pigmented molecule containing iron that carries the oxygen supply in the muscle tissue. The amount of iron found in meat is therefore usually proportional to its colour.
From a nutritional point of view, the meat is classified among the foods of the first group, i.e. those characterised by the high concentration of proteins with high biological value. The biological value of a protein molecule depends on how many essential amino acids it has, which must be consumed as food, since humans are not able to synthesise them. Meat contains 16-22 g of protein per 100 g of its raw edible form, changeable depending on the species, the breeding characteristics and the cut in question. However, proteins are not the only nutritional benefit particular to meat – it is also characterised by the presence of iron in a form more easily absorbed than that found in vegetables, and by group B vitamins. Most notable among these vitamins is vitamin B12, which is found only in food of animal origin.
Fish, too, is part of the first group of foods, and contains 15-20 g of protein per 100 g of its raw edible meat. This again can vary according to the species and breeding conditions of the fish. Like meat, fish provides bio-available iron and B vitamins, in particular, vitamin B12. In addition, fish is a good source of another important mineral, iodine, which is essential for the correct functioning of the thyroid.
But the big difference between meat and fish is in the type of fat they contain: in fish, the percentage of fat varies between different species from 0.5% to 27%, and is characterised by the high concentration of long chain omega 3 fatty acids (EPA and DHA). The positive effects of these fatty acids, in particular for the cardiovascular system, have been known for a long time: they are found exclusively in fish products, and it is recommended to consume fish at least 2-3 times a week precisely because of these fats. You may have heard bad things about the presence of mercury in fish, but remember that while it accumulates significantly in very large fish (tuna, swordfish, etc), the risk is non-existent for small-sized fish.
In conclusion, meat and fish are foods that have lots in common, but also many differences, and because of these differences, both should be included into our weekly diet, in the right quantities, of course.
Department of Agricultural and Food Sciences
University of Bologna