Weight gain varies from one pregnant woman to another, so the timing of weight gain during pregnancy cannot be generalized. In the first trimester, some pregnant women not only have no early pregnancy reaction, but also have accelerated gastrointestinal motility, and such pregnant women will start to gain weight in the second trimester. For pregnant women with severe early pregnancy reactions and inadequate nutrition in the early pregnancy, their weight may even drop slightly; when the early pregnancy reactions disappear and their appetite is restored, they will start to gain weight. In addition, weight gain is also related to the degree of food absorption in the intestine. Usually, weight gain is faster after the fifth month of pregnancy and slows down in the middle and later stages. It is recommended that women eat a reasonable diet during pregnancy to ensure balanced nutrition, can consume low-calorie foods and exercise appropriately, and avoid over-supplementation, which can result in an oversized fetus and excessive fat accumulation, leading to complications such as obstructed labor. In short, the correct nutritional supplementation is beneficial to the healthy development of the fetus.