If you don't eat anything for three days, just drink water, and run for six hours every day, you will lose weight on the first day 1 kg -2 kg, but you will be extremely tired the next day, and you will not be able to get up or run. If you run forcibly, you will not last for a few minutes. Abnormal heartbeat, leg cramps, the next day because there is no strength to do exercise, there is not much weight loss effect, if the third body does not eat, it will start to be life-threatening.
After three days, you won't lose much weight. Because you are hungry, you will drink a lot of water. If you control the amount of water you drink, your weight will drop significantly, but it will rebound quickly within 2 days after you resume eating.