GrainWhole grain foods have been an essential source of nutrients for millennia.
A cereal grain is comprised of three parts: the bran (shell), germ bud and endosperm (the nutritive tissue covering the germ bud).
The bran and the germ bud are the healthiest components of corn, because they are rich in vitamins, minerals and proteins. The endosperm on the other hand is primarily just sugar.

Why we should eat more whole grain

Whole grain contains ideally all three components (bran, germ bud, endosperm). White flour is made out of refined grain, which due to reasons of storage life only includes the endosperm and not the two important components (bran and germ bud).
Whole grain is not only rich in important nutrients, but also the type of sugar (long-chained carbohydrates) will make you feel full for a longer period of time. Consumption of refined grain products though, will make you feel hungry pretty quick.
Health wise, it’s better to eat more whole grain products and to avoid refined grain products. In the beginning it makes sense to mix both whole grain and classical refined products. That way you can slowly get used to the taste and digestion of whole grain and after a while you will make the complete change and learn to love it, since it’s not only healthier, but is also more rich in taste.