There are four phases of carbohydrate intake on a low carb diet, the induction phase calls for a daily carbohydrate intake of 20 grams, the sustained weight loss phase calls for a daily carbohydrate intake of 25 grams, the weight maintenance phase calls for a weekly carbohydrate intake that can be increased by 10 grams, and the lifetime maintenance phase calls for the possibility of choosing different foods but restricting the intake of carbohydrates. A low-carb diet is a low-carbohydrate diet that calls for strict restriction of carbohydrate intake and increased fat and protein intake in the diet. It can be divided into four phases, namely induction, sustained weight loss, weight maintenance, and lifelong maintenance. Each phase has different requirements for carbohydrate intake. The induction phase requires a daily carbohydrate intake of 20 grams; the sustained weight loss phase requires a daily carbohydrate intake of 25 grams, after which the intake can be increased by 5 grams per week. The weight maintenance period requires that carbohydrate intake can be increased by 10 grams per week while the weight is still being lost; and the lifetime maintenance period requires that different food choices can be made, but carbohydrate intake is still restricted. It is important to note that the long-term effectiveness of low-carb diets cannot be determined. Low-carbon dieters eat less carbohydrates, protein and fat will be relatively eaten more, contrary to the health concepts of the nutritional community, is not suitable for patients with coronary heart disease, hyperlipidemia, gout, renal disease and advanced liver disease. People who need a low-carbon diet should be guided by professionals and should not start blindly.