Most whole wheat breads are not made only of whole wheat flour. They contain some amount of white (all-purpose) flour, however little. The inclusion of all-purpose flour is two-fold – an improved texture in the finished product and the rise it gives to the bread when baked.
Based on regulatory standards set universally and in individual countries, breads are allowed to be marketed and sold as 100% whole wheat based on the ratio or quantity of the primary ingredient in the product, in this case, whole wheat flour. The same is true for many products sold as partly skimmed, low fat, no fat, light, sugar free etc. It is about how much is in and how much is out based on the premise of it being marketed as whole or healthy. Most, if not all of the time, if these products do not contain some of the things that are considered “bad” for us, they won’t taste good. We won’t find them appealing and we would not buy them.