Carbohydrates and fats are the important sources of energy, which must be sufficiently included in the diets. Though high content of fat and carbohydrate in diet can provide rich nutrients for organism, it also causes fatty liver, obesity, cardiovascular disease, hyperglycemia, hyperlipidemia and affect offspring development etc. The effect of different proportions of fat and carbohydrate in diets on fat metabolism, sugar metabolism and propagation and so on were briefly reviewed. The therapy effects of plant extracts on the diseases caused by the diets with different proportions of fat and carbohydrate were introduced in order to provide a reference of rational diet for people.