CHAPTER 1
What Is Metabolism?
“I’ve searched the web but found nothing that tells me how to
distinguish if my metabolism is healthy. I’ve found plenty of
ways to tell me how to improve my metabolism but nothing
that explains what is normal. Are there outward signs that
will tell you if your metabolism is healthy?”
Metabolism.com member
According to Webster’s Dictionary, metabolism is “the chemical and physical processes continuously going on in living organisms.” But when most people think about metabolism they focus on one specific process—the process that releases and stores energy from the food we eat. This is because this type of metabolism not only affects how efficiently your body burns fuel but also influences how easily our bodies gain or lose weight.
Turning Food into Energy
In simple terms, your metabolism is the rate at which your body breaks down nutrients from the foods you eat and converts them into a form the body can use. After you’ve eaten a bowl of cereal or a sandwich, chemicals produced in the digestive tract, known as enzymes, break down all of the complex molecules that make up the food into smaller, more usable nutrients. Proteins are broken down into amino acids, fats into fatty acids, and carbohydrates into simple sugars like glucose. These nutrients are then absorbed into the blood where they are transported all over the body.
At this point the nutrients can be used in different processes. Amino acids are usually used to build and repair tissues, while glucose enters cells and is metabolized for energy. Any extra nutrients left over after these processes are generally stored in body tissues, especially the liver, muscles and body fat, and used for energy at a later date if the body needs it. (Think of it like a squirrel stocking up nuts for the winter.)
In this way, the process of metabolism really is a balancing act between two very different types of activities: (1) building up body tissues and energy stores, and (2) breaking down energy-rich nutrients, body tissues and energy stores to produce fuel that will power the body. Continue reading