Preparation for pregnancy can lose weight, but to choose the appropriate way, can be through a scientific diet combined with exercise, but not recommended through dieting and taking drugs to lose weight. Obesity caused by over-nutrition may lead to endocrine disorders, decreased egg viability, it is recommended that obese women lose fat during pregnancy preparation, so that the body’s internal environment tends to stabilize, which can increase the chances of conception. Scientific diet, to ensure comprehensive nutrition at the same time, reduce the intake of calories, combined with appropriate exercise to achieve the purpose of metabolizing excess energy, fat loss. Dieting to lose weight will lead to insufficient nutritional intake, affecting the quality of eggs, can not lose weight through dieting during the preparation period; in the preparation period can not lose weight through medication, weight loss drugs may be potentially harmful to reproductive cells, and weight loss drugs usually cause diarrhea, nutrient loss and so on. During the preparation for pregnancy, scientific weight loss, weight and physical condition regulation in the ideal state, is conducive to the success of conception.