Changes in body weight in healthy adults are mainly related to changes in food intake and activity; when the energy intake from food exceeds the energy expended from activity, body weight increases, and vice versa, body weight decreases. Food energy producing nutrients are mainly proteins, lipids and carbohydrates. Because of the general increase in activity during pregnancy is not much, some also reduced, so how much weight gain during pregnancy is related to how much food intake. First, the appropriate weight gained during pregnancy The appropriate weight gained during pregnancy can refer to the Institute of Medicine (IOM) 2009) recommended value. In the use of the recommended value, to understand my body mass index (BodyMassIndex, BMI), BMI = weight (kg) / height (m) 2. Recommended value of the appropriate weight gain during pregnancy: pre-pregnancy BMI (kg / m2) total weight gain range (kg) growth rate in mid-late pregnancy (kg / week) low body weight (<18.5) 12.5-18 0.51 (0.44) -0.58) Normal weight (18.5-24.9) 11.5-16 0.42 (0.35-0.50) Overweight (25.0-29.9) 7-11.5 0.28 (0.23-0.33) Obesity (≥30.0) 5-9 0.22 (0.17-0.27) II Health Risks of Excessive Gain During Pregnancy Cesarean section rates increase as maternal Weight gain often has elevated blood lipids and blood sugar, resulting in increased probability of large children, inability to deliver successfully or difficult labor, increased cesarean section rate; postpartum weight retention; increased risk of gestational diabetes mellitus, gestational hyperlipidemia, hyperlipidemia, hyperuricemia, and so on. Third, the health risks of increasing too little during pregnancy Maternal hypoproteinemia, which can easily lead to their own edema and small fetus; iron deficiency anemia, other nutritional deficiencies, resulting in postpartum weakness, etc. . Insufficient weight gain can lead to fetal growth retardation, low birth weight babies, low immunity of newborns, and increased risk of chronic diseases in adulthood. Fourth, the principle of balanced diet in mid-late pregnancy What is the difference between the diet in mid-late pregnancy and the usual diet? The energy intake during pregnancy is only 200 kcal more than usual. The specific dietary principles are as follows. 1. Foods that must be increased (1) Milk and its products require an extra 200 ml of milk during pregnancy. (2) Animal foods need to add an extra 50 to 100 grams of meat dishes in the middle and late pregnancy. If the meat intake is not enough, you can add tofu, dried beans and other soy products. In terms of supplemental high-quality protein, soy products are a substitute for meat dishes. 2, a small increase in food (1) fruit overweight pregnant mothers are a lot of fruit to eat more caused by fruit intake during pregnancy and the same as usual, 200 to 400 grams, divided into 3 times to eat, eat a good meal 2 hours after eating. (2) staple food staple food and usual than, at most, increase 50 grams, the staple food is including cereals, potatoes and miscellaneous beans. Please pregnant mothers to remember to potatoes and miscellaneous beans as staple food. 3, do not need to increase the intake of food fat and salt we are now cooking with oil are more, pregnant mothers are not necessarily able to control, but pregnant mothers do not eat nuts, nuts are almost no direct DHA, the main complementary fat; do not eat fried rice, fried noodles and other refueling staples; do not eat pig bone marrow, do not make up for the calcium, make up for the lard. Dietary points in mid-pregnancy:1, eat a good milk, meat or soy products every day; 2, total control, small meals; 3, to maintain a suitable weight gain, after 20 weeks of pregnancy, the weekly increase in body weight of 0.4 to 0.5 kg.