During the process of digestion the body only uses the liquid from what we ingest. That liquid gets extracted from our food and the remainder becomes what is known as feces. The ideal foods for the body are those that contain an abundance of water and/or those that are easily dissolved in water. Fruits and vegetables are excellent examples of such types.
The food we eat gets liquefied by the stomach and then gets absorbed into our bloodstream through the villi in our small intestine. The less water that is contained in our food; the more trash (feces) it will produce in our body. The less water soluble the food is, the more problems it will create in the body.
Processed white (starches) foods create a lot of stress on the body because they do not dissolve easily and neither do they contain sufficient amounts of water. Eating foods of this kind creates many complications; especially constipation, which is very common among junk food eaters. These types of foods that are not easily broken down solidify in the intestine, which is the most common cause of constipation.