The Difference and Relationship Between Fat and Blood Lipids: A Scientific Analysis of Their Relationship

It's important to understand the relationship between fat and blood lipids: Although fat and blood lipids differ by only one character, their meanings are quite different. The fat we commonly refer to is adipose tissue, an important component of the human body. Adipocytes, a small number of fibroblasts, and a small amount of intercellular collagen are the main components of adipose tissue. A normal adult stores approximately 564,840 kilojoules (135,000 kilocalories) of energy in adipose tissue, enough to sustain life for 40-50 days. Recent research indicates that adipose tissue not only serves as a reservoir for storing and releasing energy but also sends out certain "signals," allowing it to play a more active role in regulating energy metabolism.

In biomedical terms, fat refers to the fat contained in adipose tissue. Adipose tissue stores most of the body's fat. Fat is composed of one molecule of glycerol and three molecules of fatty acids, hence it is also called "triglycerides." Fatty acids are broadly classified into two categories: saturated fatty acids and unsaturated fatty acids. Saturated fatty acids raise cholesterol levels and are found in high amounts in animal fats such as lard, butter, and cream; they are not suitable for excessive consumption. Unsaturated fatty acids are further divided into monounsaturated and polyunsaturated fatty acids. Monounsaturated fatty acids are found in various foods, primarily providing energy and having no effect on cholesterol levels. Polyunsaturated fatty acids are mainly composed of linoleic acid, linolenic acid, and arachidonic acid, and are most abundant in vegetable oils (such as soybean oil, corn oil, and sesame oil), fish oil, and poultry products. Polyunsaturated fatty acids have a mild cholesterol-lowering effect, making them suitable for patients with coronary heart disease and hyperlipidemia. Normally, the fat ingested by the body is digested and absorbed, then stored in adipose tissue as triglycerides. When the body's energy supply is insufficient, the stored fat in adipose tissue is broken down into fatty acids and glycerol. Fatty acids release energy through oxidation to meet the body's needs, while glycerol is converted into glucose to maintain blood sugar levels within the normal range.

Blood lipids are a general term for lipid substances contained in the blood, mainly composed of cholesterol, triglycerides, phospholipids, and free fatty acids. Blood lipids are obtained from food and processed within the body, and can also be synthesized by the body using other substances. Although blood lipids constitute only a small portion of the total lipids in the body, their physiological functions are crucial. They are transported between various tissues and directly reflect the body's lipid metabolism status, as both excessively high and low blood lipid levels can adversely affect health.