Lipids, also known as fats, play an essential role in the functioning of our body. They perform several key functions that help maintain optimal health.

First of all, lipids are an important source of energy for our body. When we eat foods high in fat, such as oils, butters and fats found in meats and dairy products, they are digested and metabolized to release energy. Fatty acids, which are the main components of lipids, can be used as fuel by our body's cells. In fact, fat provides more than twice the amount of energy per gram as carbohydrates or protein.

In addition to their role in providing energy, lipids also play an important role in energy storage. When we consume more calories than we burn, the excess calories are converted to lipids and stored as adipose tissue in our body. These fat stores serve as an energy reserve for periods of fasting or when our energy needs increase, such as during intense physical activity.

Lipids also have a crucial role in the thermal insulation of our body. Subcutaneous fatty tissue acts as an insulating layer that helps maintain our body temperature by limiting heat loss. They help us resist temperature variations and maintain a constant body temperature.

In addition, lipids play a role in protecting organs. Fat deposits around our internal organs act as a protective cushion, absorbing shock and reducing the risk of potential injury.

Finally, lipids play a crucial role in the transport of fat-soluble vitamins. Vitamins A, D, E and K are fat-soluble vitamins, meaning they require lipids to be transported and absorbed effectively by our bodies. Lipids allow the transport of these essential vitamins to the tissues where they are needed, contributing to our overall health.

In summary, lipids are essential to our body. They provide energy, store excess energy, thermally insulate our body, protect our organs and facilitate the transport of fat-soluble vitamins. It is important to consume fat in a balanced way as part of a healthy diet to maintain these essential functions and support our overall well-being.

Here is an overview of the different types of fatty acids:

Unsaturated Fat

This type of fat is divided into two classes:

• Polyunsaturated fatty acids (omega-6 and omega-3): They remain liquid at room temperature and do not solidify when refrigerated. The main sources of omega-6 fatty acids are corn, soybean and sunflower oils. However, these oils have poor resistance to high temperatures and should not be heated if one wishes to preserve these fragile fatty acids. Oily fish and the oils extracted from them are also good sources of omega-3 fatty acids, but of a different type than plants. Omega-3 fatty acids are known for their protective effect on cardiovascular health.
• Monounsaturated fatty acids (omega-9): They also remain liquid at room temperature and can withstand heat, making them suitable for cooking. Considered “good fats”, unsaturated lipids have proven beneficial effects on cardiovascular health and can contribute to better blood sugar control in people with diabetes. Avocados, most nuts and seeds, and olive, canola, and peanut oils are good sources of monounsaturated fatty acids.

Saturated Fat

Saturated fats are solid at room temperature and are more resistant to heat during cooking than unsaturated fats. Although excessive consumption of saturated fats can increase “bad” cholesterol levels in the blood, they have their place in a balanced diet. Saturated fats are found particularly in dairy products such as butter, cheese and whole milk, as well as in foods of animal origin.

Trans Fat

Hydrogenation is an industrial process that changes the configuration of unsaturated fatty acid molecules. This leads to the formation of trans fats, used in the manufacture of margarines that are more or less solid at room temperature, obtained from unsaturated vegetable oils (usually soy, corn or canola). Trans fats allow better tolerance to high cooking temperatures and provide extended shelf life. However, the harmful effects of trans fatty acids on cholesterol and triglyceride levels are well known, so it is best to avoid them.

References :

• Mozaffarian D, Aro A, Willett WC. Health effects of trans-fatty acids: experimental and observational evidence. Eur J Clin Nutr. 2009 May;63 Suppl 2:S5-21. doi: 10.1038/sj.ejcn.1602973. PMID: 19424218. (Health effects of trans fatty acids)
• Kris-Etherton PM, Innis S, American Dietetic Association, Dietitians of Canada. Position of the American Dietetic Association and Dietitians of Canada: dietary fatty acids. J Am Diet Assoc. 2007 Feb;107(2):159-65. doi: 10.1016/j.jada.2006.11.010. PMID: 17274677. (Fatty acid recommendations)