When pregnant women undergo a pre-pregnancy physical examination or create a card, they need to measure their body mass index, which is the weight in kilograms divided by the height in meters squared. Based on the body mass index, the weight range that needs to be controlled during pregnancy is determined. The standard body weight index is 18.5-25, and the normal range of weight gain during pregnancy is 20-25 pounds. If the body mass index is less than 18.5, the normal range of weight gain during pregnancy is 25-30 pounds. If the body mass index is greater than 25, the normal weight gain during pregnancy is 20 pounds. If the body mass index is greater than 28, the normal weight gain during pregnancy is 15 pounds. If the diet control effect of pregnant women is not good, they can eat according to the recipes provided by the weight control clinic to control their weight within the normal range.