Refined flour and sugar rob the body of nutrients and provide nothing but calories. Mice died from malnutrition after being fed breakfast cereals for a month.
Sucrose, for example.......sugar cane has lots of calcium which acts as a lubricant for the nerves as the synapses fire. In sucrose, it's removed.
With the advent of the industrial age, manufacturers realized that wheat germ, the kernel of wheat, had something called Lecithin which gummed up their machinery. So they removed it. If it weren't for the vitamin additives, you're essentially eating bleached grass.