The one thing people most often say to me is, "my metabolism has slowed down", but very few individuals truly understand what metabolism is or how to improve it.
Metabolism is the term used for all of the physical and chemical reactions in the body. The chemical reactions of metabolism take the food we eat and transform it into fuels and building blocks for the body. These chemical reactions are necessary for providing energy for activities such as movement and thinking, and for organ function such as digestion, and the formation of urine. These reactions are also critical for breaking down old tissue and building new tissue.
The foods that we consume are chemically complex. They must be broken down by the body into simpler chemical forms called nutrients. Nutrients are taken in through the intestinal walls and transported by the blood to the cells. The processes involved are called digestion, absorption, and metabolism.
Digestion begins the process through a series of physical and chemical changes by breaking down the food in preparation for absorption from the intestinal tract into the bloodstream. Digestion actually begins when chewing breaks large pieces of food into smaller pieces.
The next step in this process is absorption. Absorption takes place primarily in the small intestine, where its surface area is comparable to a quarter of a football field and its length is 20 feet. That's pretty amazing, isn't it?
Nutrients are taken up by the intestines and passed into the bloodstream to facilitate cell metabolism. Within 3 to 4 hours after a meal has been eaten, the body must find a way to absorb millions of nutrient molecules including amino acids (proteins), monosaccharides, monoglycerides, glycerol (carbohydrates), fatty acids and glycerol (fats),vitamins, and minerals.
A whole lot of stuff goes on here, with villi (several hundred cells covered with microscopic hairs) in constant motion, trapping nutrient molecules and digesting and absorbing them into the cells.
By the time we get to metabolism, the handling of food within the body has reached its final stage. The process of metabolism involves all the chemical changes that nutrients undergo from the time they are absorbed until they become part of the body or are excreted from the body. Metabolism is the conversion of the digested nutrients into components for energy or for building material for living tissue.
Metabolism happens in two general phases that occur simultaneously, anabolism and catabolism. Anabolism (uses energy) involves all the chemical reactions that the nutrients undergo in the construction or building up of body chemicals and tissues such as blood, enzymes, and hormones.
Catabolism (releases energy) involves the reactions in which various compounds are used to do the body's work produce heat, or to be stored for later use.
Energy from carbohydrates, fats, and protein for the body's cells, comes from their conversion to glucose, which combines with oxygen in a series of chemical reactions that form carbon dioxide, water and cellular energy. The energy is used for body functions, and the carbon dioxide and water are waste products that are carried out of the body by the bloodstream.
The process of metabolism requires that extensive systems of enzymes be maintained to facilitate the thousands of different chemical reactions that must be performed, and also to regulate the rate at which these reactions proceed. The presence of protein, vitamins, and minerals is essential for these enzymes to perform their functions at their very best.