Substituting whole wheat flour for all-purpose flour:
You can replace part but not all of the all-purpose flour with whole wheat flour when baking. Blending whole wheat flour with all-purpose flour will lighten the finished product while maintaining the nutritional benefits of whole wheat.
When baking, use half all-purpose flour and half whole wheat flour. The end product might not look the same, and it could have a coarser texture and less volume.