The vast majority of obesity is caused by an imbalance between calorie intake and calorie consumption income and expenditure, which is commonly known as eating too much. First we need to understand what control our appetite. Appetite is regulated by a variety of factors, such as blood sugar, leptin, hunger hormone, the wrong gallbladder peptide, etc.. The ultimate factor that makes us feel hungry is hunger hormone, and it is what often makes us “unable to control our mouths” will not, leading to weight loss failure and weight rebound. Previous studies have found that if the body reduces energy intake, the hunger hormone will rise at the next meal, making people full of appetite. A recent study from the University of Cincinnati makes a surprising point: hunger hormones are stimulated by the fat in food. The study, published in Nature Medicine, found that hunger hormone is not active as soon as it is made; it has to undergo an acyltransferase process to become active. The researchers found that the amount of active hunger hormone was not elevated during fasting. Once you start consuming high-fat foods, the level of active hunger hormone rises rapidly. We may also have experience in our lives that food made with more oil tastes better and smells better, and that making high fat soup also requires frying the food, etc… Our appetite may be stimulated by the fat in food. How do we control calorie intake? You cannot destroy your own absorption capacity to control your weight at the moment. Many studies have investigated that the hunger control hormone method of keeping calories out of the body is the least harmful method to the body. However, there are still few methods to control hunger factor, and only self-control can be adjusted. However, for patients with a BMI greater than 32, this can only be done through weight loss surgery. There are pros and cons to everything, and in order to protect the health of the body, weight loss surgery is only a push to control caloric intake for a few years. But to truly guarantee a lifelong non-rebound, the patient’s own cooperation and efforts are needed.