What is Metabolism?

Some people think metabolism is a kind of organ, or a body part, that influences digestion. 

Actually, the metabolism isn’t a body part. 

Metabolism, is the process of transforming food (e.g. nutrients) into fuel (e.g. energy).  The body uses this energy to conduct a vast array of essential functions. 

In fact, your ability to read this page is driven by your metabolism. 

If you had no metabolism you wouldn’t be able to move. 

In fact, long before you realized that you couldn’t move a finger or lift your foot, your internal processes would have stopped, because the basic building blocks of life – circulating blood, transforming oxygen into carbon dioxide, expelling potentially lethal wastes through the kidneys and so on – all of these depend on metabolism. 

Although we think of our metabolism as a single function, it’s really a catch-all term for countless functions that are taking place inside the body.  Every second of every minute of every day of your life numerous chemical conversions are taking place through metabolism, or metabolic functioning. 

In a certain light, the metabolism has been referred to as a harmonizing process that manages to achieve two critical bodily functions that seem to be at odds with each other. 

Anabolism and Catabolism

Our bodies are continually creating more cells to replace dead or disfunctional cells.  For example, if you cut your finger, your body starts the process of creating skin cells to clot the blood and start the healing process instantly. This creation process is a metabolic response, and is called anabolism.

On the other hand, there is the exact opposite activity taking place in other parts of the body.  Instead of building cells and tissue the body is breaking down energy so the body can function. 

For example, as you exercise, your body temperature rises and your heart beat increases.  As this happens, your body requires more oxygen, so your breathing increases.  If your body couldn’t adjust to this enhanced requirement for oxygen, you would collapse. And all of this requires additional energy. 

Presuming that you aren’t overdoing it, your body will begin converting food into energy in a metabolic process called catabolism.

Your metabolism is a constant process that works in two seemingly opposite ways: anabolism uses energy to create cells, and catabolism breaks down cells to create energy. 

The metabolism is a harmonizer. It brings together two seemingly opposite functions, and does so in an optimal way that enables the body to create cells as needed, and break them down, again as needed.

 

Metabolism and Weight Loss

Calories

Calories are simply units of measure, not actual things.  They are labels like an inch which really isn’t anything, but it measures the distance between two points. 

So what do calories measure? 

Energy.

Your body creates energy from the food you eat, whether it's healthy food or not. It creates energy from fruits and vegetables using the same process that it uses to create energy from chocolate bars and candy.

While you know it's better for your body to get energy from fruit and vegetables, your body doesn't evaluate the food. It creates energy from whatever you feed it.

It sounds strange, but the body really doesn’t care.  To the body, energy is energy.  It takes whatever it gets, and doesn’t really know that some foods are healthier than others.  It’s kind of like a garbage disposal: it takes what you put down it, whether it should go down or not.

So let’s apply this to the body, and to weight gain.  When the body receives a calorie it must do something with that energy.  If a carrot delivers 100 calories to the body, it has to accept those 100 calories.  The same goes for 200 calories from chocolate bars and candy. 

The body does one of two things to the energy, it either metabolizes it via anabolism, or it metabolizes it via catabolism.  That is, it will either convert the energy (calories) into cells/tissue, or it will use that energy (calories) to break down cells.

When there is an excess of energy, and the body can’t use this energy to deal with any needs at the time, it will be forced to create cells with that extra energy.  It has to. 

It doesn’t necessarily want to, but after figuring out that the energy can’t be used to do anything (such as help you exercise or digest some food), it has to turn it into cells through anabolism. 

And those extra cells?  Yup, you guessed it: added weight.

In a nutshell, the whole calorie/metabolism/weight gain thing is really just about excess energy.  When there are too many calories in the body, they are transformed into fat. 

Sometimes those extra calories are transformed into muscle. In fact, muscles require calories to maintain their mass, so people with strong muscle tone burn calories without actually doing anything; their metabolism burns it for them. 

This is the primary reason why exercising and building lean muscle is part of an overall program to boost your metabolism. The more lean muscle you have, the more places excess calories can go before they’re turned into fat.

A Final Word About Fat

There’s a nasty rumor floating around that fat cells are permanent.  Unfortunately, the rumor is true. Most experts agree that once fat cells have been created, they're permanent.  But this doesn’t spell doom and gloom for those of us who could stand to drop a few pounds. Even though experts believe that fat cells are permanent, they also agree that fat cells can be shrunk.  So even if the number of fat cells in your body remains the same, their size, appearance and percentage of your overall weight, can be reduced.