The reason is the high production cost of whole wheat flour and healthier whole wheat flour.

1. Whole wheat flour is directly ground from wheat with bran. Compared with refined flour separated from wheat bran, the production process of whole wheat flour is more complicated and requires more energy and time. At the same time, whole wheat flour needs better planting conditions, such as better soil and climate, which increase the cost of whole wheat flour.

2. Whole wheat flour retains the crude fiber, vitamins and minerals in bran, which has higher nutritional value and is healthier, but the price will be higher accordingly.