What is metabolism?
Every time you eat food or have a drink, your body begins the process of breaking it down and processing the nutrients from the food you have eaten. It is these nutrients that turn into the energy you use to perform various activities. The process of converting food to energy is called metabolism. All of your food gets broken down into different energy-giving components through this process.
How does metabolism work?
Let us explain how metabolism works through an example. When you eat a slice of watermelon, your body will break down the watermelon by extracting the water content and the natural sugar in the fruit. These nutrients will get converted to minerals and glucose compounds. Next, these compounds will get absorbed in the blood stream and get transported to different cells in the body, which will further metabolise the compounds and extract energy from them. This energy, in addition to getting used by the body, also gets stored in different parts of the body like body tissues, muscles, the liver and body fat. Similarly, protein gets converted into amino acids, fat gets converted to fatty acids and carbohydrates get converted to glucose and a similar absorption and conversion process follows. This conversion process is known as metabolism.
Are there different types of metabolic activities?
There are two types of metabolic activities that are continuously taking place in the body:
Anabolism: Also known as constructive metabolism, it mainly involves building and storing metabolic activities. This metabolic activity supports the growth of new cells, helps maintain body tissues and also stores energy in the body for future use.
Catabolism: This metabolic activity on the other hand is known as destructive metabolism. This metabolic activity is mainly responsible for breaking up food molecules to provide energy to the entire body in order to function. Catabolism also provides fuel for storage purposes, in other words anabolic activity in the body. The rest of the energy produced helps the body maintain temperature, enables the body to move, provides muscular function, etc.
What is basal metabolic rate?
Just like a car needs fuel to run the engine, the body too needs food as fuel to function. However, if you overfill the car's fuel tank with excess petrol it is likely to overspill. Similarly, if you have a calorie-dense diet, all the excess energy derived from the food gets stored as fat in the body. This is where exercise comes in handy. Whenever you exercise, your body burns extra fuel, which in turns creates a balance that was previously missing. However, how many calories you burn in a day, is also a function of the fat/muscle ratio in your body and a measure known as your basal metabolic rate (BMR).
How does your BMR affect your body?
Going back to the car example, a car provides an average at which fuel gets consumed per kilometre, similarly the BMR is an average of how many calories a person burns while at rest. To some extent, a person's BMR is genetic; however, it can also get affected with health problems that slow down your BMR. A higher BMR means your body is capable of burning more calories than a person with a low BMR, even though the height, muscle ratio and level of activity may be the same. Having a low BMR could be the reason why one person piles on the kilograms while another person who eats the same amount of food doesn't seem to gain any weight!