The reason why running on an empty stomach is discouraged is that if you run to lose weight, you will consume more energy during running. If it is not supplemented in time, it may bring irreparable harm to the body, which will be harmful to the body in the long run. In addition, because running consumes too much, the hunger will be stronger after running, so it may make you eat more food unconsciously, increase the chance of weight gain, and lead to the opposite effect of running to lose weight. Thank you.