That theory is wrong. It is the most scientific exercise way to gain muscle first and then lose fat. Practice has proved that the so-called muscle training after eating fat and muscle training after reducing fat are too different. The former will be like a bucket, and the latter will be symmetrical and clear. There will be a small amount of muscle consumption while losing fat, so it is impossible to lose fat and gain muscle at the same time. When the body fat content drops to 8%, systematic muscle training can be carried out. If people with high body fat content, during exercise, substances such as cellulose in fat can quickly increase muscle fiber and gain muscle, with obvious effect. If the fat content is low, it is thin, and chickens have to transport nutrients to gain muscle, instead of using them directly. So fat people exercise and their muscles grow fast.

Extended data:

Lipid is a general term for oil, fat and lipid. The fat in food is mainly fat. Generally speaking, liquid at room temperature is called oil, and solid at room temperature is called fat. Fat is composed of three elements, C, H and O. Fat is a triacylglyceride composed of glycerol and fatty acids, in which the molecule of glycerol is relatively simple, but the types and lengths of fatty acids are different. Fatty acids are divided into three categories: saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids. Fat is soluble in most organic solvents, but insoluble in water. Is glyceride C3H5(OOCR) 3 one or more fatty acids?

References:

Baidu encyclopedia-pang