Eating lean fish allows you both to increase your percentage of protein and to lower the percentage of fat in your diet. Fish are aquatic vertebrates with a streamlined body, usually covered with scales, that move through the water using fins and that breathe through gills. Although some species are dwindling (turbot, salmon), other species that were once underrated or looked down upon, such as monkfish, are now filling in the gaps and providing us with a wide variety. Aquaculture, practiced by the ancient Romans, is once again becoming increasingly important. It contributes to the preservation of some species that otherwise would be threatened with extinction - sea bass, gilthead seabream, turbot and sturgeon.

Buying fish
Modern means of transportation allow fish to be shipped quickly and ensure the utmost freshness. For this reason, we now have access to fish that were once considered exotic.

It is essential that fish be very fresh, unlike meat that becomes more tender after a few days in a cold room.

Scale-less fish, such as eel, do not keep well and should be bought live.

Nutritional value of fish
The tender flesh of fish is more digestible than meat. It gives the impression of being less nourishing, but in fact it is lower only in fat, particularly in the saturated animal fats that promote cardiovascular disease. Remember that the unsaturated fats found in fish are more like vegetable oils. Not only do they not contribute to an increase in blood cholesterol levels, but they actually promote its elimination by the liver.

There are three categories

Lean fish
These are the most numerous: sea bass, cod, plaice, hake, sea bream, haddock, dab, skate, John Dory, sole, etc; 100 g of flesh from these fish contains only 0.3 to 1 g of fat and 65 to 80 calories.

Semi-fatty fish
This category includes conger, halibut, sea robin, herring, monkfish, whiting, mullet, red mullet, sea trout and turbot; 100 g of their flesh contains from 2 to 10 grams of fat and between 90 and 160 calories.

Fatty fish
These include eel, mackerel, salmon and tuna; 100 g of their flesh contains 10 to 15 g of fat and between 180 and 225 calories.

Fish are as high in protein as meat, containing approximately 18 g of protein per 100 g of fish. No matter what category they fall into, fish contain no carbohydrates. They are a source of essential amino acids (since our body does not synthesize them), are rich in phosphorus and calcium, and contain iron and vitamins, particularly from the A and B groups. In the case of lean fish, the caloric content is one-third lower than chicken flesh, and only half that of red meat, even with its visible fat removed.

In the case of fatty fish, the caloric and fat contents are almost equal to those of red meat with its fat removed, but fish has the advantage of containing only unsaturated fats, which promote the metabolizing of cholesterol.

Furthermore, fish oils contain unsaturated fatty acids, called omega 3, which are not contained in vegetable oils, and which are believed to have a particularly beneficial effect on blood vessel walls.