Basically, the nutrients are stripped out, and then a handful are added back in, resulting in too much of some, and too little of others.
When flour is refined, it is not just bran that is removed. The wheat germ, an important part of the grain containing oils and the nutrients in the grain that are responsible for the potential for life and growth in the grain, is removed also. The remaining white starch is relatively devoid of nutritional variety.
What is left of the grain is little more than a bit of simple carbohydrate, which converts so rapidly to sugar in the body that it is not far different from eating sugar directly. Addition of preservatives and chemicals does not help the situation any, nor does the addition of supplementary vitamins and minerals. They are added back in unnatural amounts and proportions, and only a small amount of the total number are added back in. Added nutrients also may not be in the most digestible forms.
This information was written by Laura Wheeler, Owner of Firelight Business Enterprises, Inc. Her explanation made the most sense after reading numerous other sources.So basically we are eating the sugar that our bodies cannot metabolize which leads to oxygen starved cells.