Many people with anorexia have a very thin appearance and fall down when the wind blows, yet they are very energetic and feel better about themselves than when they were at a normal weight. People around them are also confused. They eat so little and are so thin, but they work harder than anyone else and get better grades, and they also do heavy exercise, so could it be that they have become gods and are not eating? Why do anorexics behave this way? There are two reasons: 1, physiological reasons: starvation state, the human body endocrine will appear some changes. One of these substances – cortisol secretion increases. When people are under stress, such as nervousness and anxiety before exams, panic and heartbeat after shock, etc., are caused by cortisol secretion, and this substance soon declines after the stress, and people’s emotions return to normal. While anorexia patients continue to starve, cortisol levels continue to rise, anorexia patients will show euphoria, energy, concentration, etc., but at the same time there will be emotional instability, irritability and other performance. This continuous state of tension and hyperactivity will lead to further deterioration of the patient’s physical condition and eventually weakness and even heart failure. Therefore, the energy level of anorexia patients is only a temporary and superficial illusion. This phenomenon only means that the patient’s body is in a state of hunger. 2, psychological reasons: anorexia patients lose weight successfully, will win the praise of others, patients feel better than others, and different from others, etc. This is the spiritual motivation of anorexics. Under the support of this strong spiritual motivation, anorexia patients will also be more motivated to lose weight and do things. And this reckless desperation accelerates the process of physical exhaustion. Therefore, the self-perception of anorexia nervosa patients as well as their energy level is actually a pathological manifestation. However, anorexics themselves often use this as an excuse to refuse treatment, and even parents often ignore the seriousness of the problem because of this illusion, thus delaying treatment. Through this article, I hope to help people with anorexia nervosa and their families to get out of the misunderstanding and to reconnect with the superficial phenomenon of “high energy” in anorexia nervosa, and to correct it as soon as possible.