> I’ve read a doctor saying when we fast the liver pulls glucose and pumps it into the body but I’m not so sure about it.
It’s true. Your body stores glucose in the liver and the muscles. When you fast, it will pump out the stored glucose to fuel itself. This is exactly the point of fasting — to let your body use up that stored fuel. I recommend reading Dr. Jason Fung’s books to learn more — or you can watch some of his YouTube videos. For now, check out this Q&A post.