Blood donation will not lead to weight loss, and blood donation will not lead to weight loss. Generally speaking, losing weight is consumed in the previous 1 ~ 3 weeks, and the effect of strengthening exercise and taking diet pills will only have obvious effect in 3 ~ 5 days. I've given blood myself, and I haven't lost weight overnight. Generally, there is no problem in the range of 200 ~ 400. However, due to the reduction of blood volume, the body itself will consume a certain amount of blood volume when it makes blood again, which may make it lose a little weight. It is normal that its weight fluctuates within 1KG. Don't worry. Drink plenty of water and replenish water. It doesn't matter if you don't have dizziness, headache, nausea and vomiting.