The human body produces oils and other substances that circulate in the bloodstream. An example is insulin, which is secreted from the pancreas in response to the increase in the amount of sugar coming from the food that the person eats. The cells then absorb this, which gives the individual calories that are used as energy.
Another substance that the body produces naturally is cholesterol. This is also ingested in the food people eat. There are two types of cholesterol namely LDL an