This results in a quick rise in blood sugar which is soon followed by a drop in blood sugar which is interpreted by the body as a craving for more sugars. This sugar low may also result in fatigue, dizziness, nervousness, and headache. However, not all carbohydrates do this. Most fruits, vegetables, legumes, and whole grains are digested more slowly. Fats, which are lipids, are the source of energy that is the most concentrated.
Fats produce more that twice the amount of energy that is in carbohydrates or proteins.
Besides having a high concentration of energy, fat acts as a carrier for the fat soluble vitamins, A, D, E, and K. Also, by helping in the absorption of vitamin D, fats help make calcium available to various body tissues, in particular, the bones and teeth. Another function of fat is to convert carotene to vitamin A. Fat also helps keep organs in place by surrounding them in a layer of fat. Fat also surrounds the body in a layer that preserves body temperature and keeps us warm. One other function of fat is to slow the production of hydrochloric acid thereby slowing down digestion and making food last longer. Some sources of fats are meats and nuts as well as just plain oils and fats.