Fats include three major categories: triglycerides, cholesterol and phospholipids. Triglycerides, also known as neutral fats, are the main type of fat that is normally referred to. Neutral fats are compounds composed of glycerol and fatty acids, and are found in high levels in fatty meats, lard, butter, cream, vegetable oils and various nuts. Depending on their sources, fats can be divided into animal fats, which are mainly composed of saturated fatty acids, and vegetable fats, which contain a large amount of unsaturated fatty acids. Fat is an important energy supplier in the body, and fat contains more than twice as many calories as carbohydrates and proteins, with each gram of fat providing 9 calories. Some fats are important for the absorption of fat-soluble vitamins, and when too little is consumed, the absorption of vitamins A, D and E, which can only be dissolved in fat, may become impaired. In addition to this, the fat layer in the body has a protective function for the body by keeping it warm and shockproof. Cholesterol is a small molecule fat, which is not only an important component of the organism, but also a precursor of the body’s synthesis of some hormones (such as cortisol, which belongs to the same category as hydrocortisone in drugs) or vitamins (such as vitamin D). Phospholipids are a class of phosphorus-containing lipids, which are also important components of the body and have important physiological functions in the body’s metabolism. As you can see, fats are an important component of food and one of the main components of the human body. After being digested in the gastrointestinal tract, fats are broken down into glycerol, fatty acids and other components, which, when absorbed, are used as a source of important energy and material metabolism, and excess glycerol and fatty acids are then synthesized and stored as fats in the body.