Eating fat, if not consumed, is converted into fat. Fats ingested by the body are digested in the small intestine and converted into fatty acids and triglycerides. After that, short-chain fats and medium-chain fatty acids can go directly into the epithelial cells of the small intestine and enter the bloodstream, while long-chain fatty acids need to pass through the celiac particles to enter the bloodstream. All glycerol and fatty acids eventually enter the liver for processing. Fatty acids and glycerol that are not oxidized and broken down to provide energy are transported out of the liver by low-density lipoproteins in the liver and through the bloodstream to reach various tissues of the body, especially the mesentery, or the subcutaneous adipose layer to be stored as body fat. Therefore, after excessive intake of fat, it is converted into the body’s own fat, which leads to weight gain and obesity problems. Fat is very high in calories, and every 1 gram of fat can be broken down to form 9 calories, so if you need to control your weight, the first thing you should do is to reduce your fat intake in moderation. Excessive fat intake can also trigger hyperlipidemia, hypercholesterolemia and many other problems, increasing the incidence of cardiovascular and cerebrovascular diseases. Dietary guidelines recommend that adults consume 25-30 grams of cooking oil a day to meet the body’s needs.