Eating the whole plant, including the skin or outer hulls can have many benefits.
The recommendation to include whole foods in the diet goes far beyond maintaining a healthy weight; it may well prevent conditions such as osteoporosis that requires adequate supplies of vitamins and minerals in the proper balance especially in women beginning in their early teens.
Links:
[1] http://www.takingcharge.csh.umn.edu/create-healthy-lifestyle/diet-nutrition/consider-food-medicine
[2] http://www.takingcharge.csh.umn.edu/explore-healing-practices/food-medicine/how-are-food-and-environment-related