The good and the bad fats
Their role
The consumption of lipids (this is the scientific name of fats), whatever their nature, it is essential to the body for many reasons:
- form cell membranes
See also
- they are part of the composition of tissues, especially those of the brain
- they allow the creation of hormones and other chemicals
- they are the basis of the synthesis of bile salts that intervene in the digestion process
- they carry some vitamins in the body: A, D, E and K.
Fatty acids and health
Lipids are made up of small elements called fatty acids. There are various families, with different characteristics, depending on their chemical formula:
- saturated fatty acids are characterized by the resistance to alteration that characterizes fats in contact with air or light and are generally solid at room temperature. Called "bad fats", they have the drawback of increasing the synthesis of cholesterol and promoting cardiovascular problems, especially in the case of hereditary predisposition, or due to diabetes, smoking or stress.
- Unsaturated fatty acids, called "good fats", are divided into two categories. Monounsaturates protect the arteries by causing the decrease in bad cholesterol. Polyunsaturated fats also protect from a cardiovascular point of view. It is precisely among the latter that we find the famous essential fatty acids, that is, those that our body cannot produce, but which are essential for its functioning: Omega3 (which thin the blood, improve mood, preservation of skin tissues ... ) and Omega 6 (which lower bad cholesterol, help structure cells…).
- Sometimes it may happen that polyunsaturated fatty acids are, unfortunately, transformed by the agri-food industry into "trans" (hydrogenated) fatty acids, accused of increasing bad cholesterol and promoting the appearance of certain types of cancer.
Where to find them
No food contains only one type of fatty acid, but it is always a mixture of variable proportions. However, certain fatty acids are found in higher quantities in some foods:
Type of fatty acid
Food
Saturated fatty acids
milk (especially whole milk), cheeses, cream, butter, cold cuts, meats,
Monounsaturated fatty acids
olive, rapeseed, peanut oil, various seed oil, oil fruits (almonds, pistachios, hazelnuts, walnuts)
Polyunsaturated fatty acids of the Omega 3 series
Fatty fish (tuna, mackerel, sardine, herring ...), rapeseed, soybean, linseed, walnut oil
Polyunsaturated fatty acids of the Omega 6 series
Eggs, butter, dairy products, oleiferous fruits, rapeseed, sunflower, walnut, corn, grape seed, borrana, evening primrose oil
"Trans" (hydrogenated) fatty acids
Biscuits, sweets, industrial bread containing fats, margarines and sauces, dessert creams, industrial ice creams, chips
Some recommendations
Indispensable for the body, lipids must in no case be eliminated from food, even when you intend to lose weight. According to official figures, they must represent between 30 and 35% of the daily energy intake (proteins 10-15%, carbohydrates 50-55%). Despite this, to preserve one's health, especially from a cardiovascular point of view, it is important to vary the intake of fatty acids, respecting these proportions: 25% of saturated fatty acids, 50% of monounsaturated acids, 25% of polyunsaturated fatty acids .
Practically:
- It is necessary to limit the consumption of fatty dairy products, eggs, meats and cured meats, and absolutely avoid processed fatty products such as snacks, chips, ready meals ...
- Instead, we must encourage the consumption of fatty fish (at least once a week) and olive or rapeseed oil (about two tablespoons a day for cooking or seasoning).
- As for butter, 10 grams per day are enough, preferably raw, for example spread on bread or melted on cooked vegetables.
