It is recommended to eat whole wheat bread when exercising, because it is full. Whole wheat flour contains high dietary fiber, which takes a long time to digest and is full. In other words, the biggest problem faced by people who have lost weight is that they are hungry and can't control their mouths. Whole wheat is a food with medium GI and high GL, and it is not easy to cause the rapid rise and fall of blood sugar, thus reducing the insulin concentration.