Fatty acids are a class of organic compounds that are widely found in nature. According to the different molecular structures, fatty acids can be divided into two categories: saturated fatty acids and unsaturated fatty acids.

Saturated Fatty Acids (SFA) do not have a double bond on the carbon chain, i.e., the connections between carbon atoms are all single bonds. They are found mainly in animal foods such as meat, dairy products and butter. Excessive intake of saturated fatty acids may lead to elevated blood cholesterol levels, thereby increasing the risk of cardiovascular diseases. Therefore, people are advised to consume saturated fatty acids in moderation to maintain good health.

Unsaturated Fatty Acids (UFA) have at least one double bond on the carbon chain and are classified into Monounsaturated Fatty Acids (MUFA) and Polyunsaturated Fatty Acids ( PUFA.) Monounsaturated fatty acids are mainly found in vegetable oils such as olive oil and peanut oil, which have the effect of lowering cholesterol and preventing cardiovascular diseases.

Polyunsaturated fatty acids include omega-3 and omega-6 types, which are found in fish, flaxseed oil and other foods. They play an important role in maintaining human physiological functions, such as regulating blood lipids, anti-inflammatory and antioxidant. However, excessive intake of polyunsaturated fatty acids may also have adverse health effects, so moderate intake is needed.

Fatty acids:

1. Energy source: Fatty acids are one of the most important sources of energy for the body. When the body needs energy, fatty acids are broken down into acetyl coenzyme A, which enters the tricarboxylic acid cycle to produce energy.

2, cell structure: fatty acids are an important component of the cell membrane and cell organelles. They can regulate the fluidity and stability of the cell membrane and maintain the normal function of the cell.

3, the transportation of fat-soluble vitamins: fatty acids can help fat-soluble vitamins (such as vitamins A, D, E and K) in the body for absorption, transit and storage.

4, hormone synthesis: fatty acids are involved in the synthesis and regulation of hormones, such as androgens, estrogens and prostaglandins. These hormones have an important impact on the physiological functions of the human body.

5. Organ protection: Fatty acids can serve as the body's natural protective layer to protect internal organs from external damage. For example, the fatty tissue in the brain can buffer the external impact and protect the brain.