Metabolism is the amount of energy (calories) our body burns to maintain itself. It is essentially the speed at which our body’s motor is running.The speed at which our body burns calories is called the metabolic rate.
Metabolism literally means “transformation.” It is the term used to describe the process by which your body changes caloric intake into energy for all of your bodily processes. Your body’s metabolism is running all of the time while you are exercising, while you are eating, and even while you are sleeping in order to help your body:
create new cells and tissue
maintain its temperature
perform all bodily activities
Metabolism is generally measured according to your basal metabolic rate (BMR). This is a calculation of how quickly your metabolism works when you are resting. BMR can be calculated by any health professional using special equipment. Your Basal Metabolic Rate (BMR) is what your body needs at rest to maintain normal functions like beating of heart, respiration and the maintenance of body temperature at a thermostatic setting just under 100 deg. All these mechanical and thermometric functions require a base level of energy. About 60-75% of energy is expended by the body at rest in such activities. You use another 10% of calories to digest and metabolize food.
Your body’s metabolism is based on the food that you eat. Your body gets all of its energy from plant and animal products that you ingest on a daily basis. This energy is measured in calories. After you eat your food, your body breaks down the different components into energy that it can use to run different cellular processes. Special molecules, called enzymes, which are released by your pancreas and thyroid gland, help to break your food down into sugars, amino acids, and fatty acids. These three types of energy are then absorbed into your bloodstream and transported to all of the different cells in your body to help to run all of your body’s different processes. Any excess energy is then stored by your body as muscle or fat so that it can be used in the future.
Factors Affecting Metabolism
There are a number of different factors affecting metabolism. The most important factor is the amount of lean muscle mass that your body contains. Lean muscle mass burns energy all of the time, even when you are not actively working out. It also burns more calories than any other part of your body. The more lean muscle mass you have, the higher your metabolism will be. Other factors affecting metabolism include:
Age: As you age, your metabolism naturally slows down. This is because the body loses lean muscle mass over the years. Expect your metabolism to decline by about 2% every decade after the age of 20.
Sex: Men have naturally higher levels of lean muscle mass. This means that women will generally have lower metabolisms than men.
Height: People who are taller have a greater surface area for their bodies to fuel. As a result, taller people tend to have a more active metabolism and require more calories in order to stay energized.
Family History: Your genetic makeup will also play a role in your metabolism. Some families have a naturally high metabolism, while others have a naturally low metabolism.
Eating Habits: The more often you eat, the more active your metabolism will be. If your body doesn’t get a regular supply of calories, it will enter into “starvation mode,” during which your metabolism will slow down and store excess energy as fat. This is why many people who are trying to lose weight suffer from the yo-yo dieting syndrome.
Basal Metabolic Rate can be calculated by the following formula of the World Health Organization.
Female = [ 655+(9.6 x Weight in kilogram) + (1.7 x Height in centimeter) – (4.7 x Age) ]
Male = [ 66+(13.7 x Weight in kilogram) + (5 x Height in centimeter) – (6.8 x Age) ]