Lipids

Definition
With the term lipids, we actually indicate i fat. These are made up of small elements called fatty acids. Depending on their chemical formula, they are organized into different families:
- saturated fatty acids are characterized by a resistance to degradation that occurs in fats under the influence of air or light, and are solid at room temperature.
- unsaturated fatty acids are divided into two categories: monounsaturated and polyunsaturated. Among the latter we find the famous essential fatty acids, which our body cannot manufacture but which are essential for its functioning: Omega 3 and Omega 6.
- Some polyunsaturated fatty acids are transformed by the food industry into "trans" fatty acids, ie hydrogenated fats strongly associated with the increased risk of heart disease.

From an energy point of view, 1 g of lipids, of any type = 9 calories.

Role
The consumption of fats, of whatever nature they are, is essential for the body for various reasons:
-form cell membranes.
- they enter into the composition of tissues, especially brain.
- they allow you to make hormones and other chemicals.
-are at the basis of the synthesis of bile salts, which intervene in digestion.
- some vitamins are introduced into the body: A, D, E and K.
Depending on their nature, lipids can have beneficial or harmful effects on health.
Called « bad fats ", the saturated fatty acids they have the drawback of increasing the synthesis of cholesterol and favoring cardiovascular disorders, especially when there is a predisposition for heredity, diabetes, smoking, stress ...
On the contrary, i monounsaturated they protect our arteries thanks to the action of reducing bad cholesterol.
Also polyunsaturated protect on the cardiovascular level, especially Omega 3 (which thin the blood, improve mood, protect skin tissues ...) and Omega 6 (decrease in bad cholesterol, cell architecture ...), as opposed to "trans" fatty acids, accused of increasing bad cholesterol and promoting the appearance of certain types of cancer.

Where are
No food contains only one type of fatty acid, but several, in varying proportions. Despite this, we find some fatty acids especially in some foods:
- Fatty acids saturated cheeses, cream, butter, cured meats, meat, palm oil. - Monounsaturated fatty acids cookies, pastries, fattened breads, some margarines and spreads, desserts, non-artisanal ice cream, chips ... : olive oil, rapeseed, peanut oil, nuts (almonds, pistachios, hazelnuts, walnuts).
- Polyunsaturated fatty acids of the Omega 3 series: fatty fish (tuna, mackerel, sardine, herring ...), rapeseed, walnut, soybean, linseed oil.
- Polyunsaturated fatty acids of the Omega 6 series: eggs, butter, dairy products, nuts, rapeseed, sunflower, walnut, borage, evening primrose oil.
- "Trans" fatty acids: : milk (mostly whole),

Needs and advice
Lipids are essential to the body and must never be eliminated from food, even when you want to lose weight. They should represent 30 - 35% of the daily energy intake (+ proteins 10 - 15% and carbohydrates 50 - 55%). Nevertheless, to stay healthy, especially from a cardiovascular point of view, it is important vary the fatty acids, respecting certain proportions: 25% of saturated fatty acids, 50% of monounsaturated fatty acids, 25% of polyunsaturated fatty acids.
In practice, it is necessary to limit the consumption of fatty dairy products, eggs, meats, cured meats, and to avoid industrial fatty products such as pastries and brioches, french fries, biscuits, ready meals ... encourage the consumption of fatty fish (at least once a week) and oil such as canola or walnut oil (about 2 tablespoons a day for cooking or seasoning). As for butter, 10 g per day is sufficient, preferably raw, for example spread on bread or melted on cooked starchy or legumes.