So what is Metabolism?
This word “metabolism” is used a lot these days.
You know that if yours is too slow you might gain weight. But what exactly does this all mean?
In technical terms “metabolism” is the word to describe all of the biochemical reactions in your body.
It's how you take in nutrients and oxygen and use them to fuel everything you do.
Your body has an amazing ability to grow, fix itself, and generally stay alive. And without this amazing biochemistry you would not be possible.
Metabolism includes how the cells in your body:
● Do activities you can control (e.g. physical activity etc.).
● Do activities you can't control (e.g. heart beat, wound healing, processing of nutrients & toxins, etc.).
● Allow for excess energy to be stored for later.
So when you put all of these processes together then you can imagine that these processes can either work too quickly, too slowly, or just right. (kind of like Goldilocks!)
Which brings us to the “metabolic rate”.
This is how fast your metabolism works.
It is measured in calories.
The calories you eat can go to one of 3 places:
● Work (i.e. exercise and other activity, like breathing or blinking).
● Heat (i.e. from all those biochemical reactions).
● Storage (i.e. leftover “unburned” calories stored as fat).
As you can imagine the more calories you burn as work or by creating heat the easier it is to lose weight & keep it off. This is because there will be fewer “leftover” calories to store as fat.
There are a couple of different ways to measure metabolic rate. One is the “resting metabolic rate” (RMR).
This is how much energy your body requires when you're not being physically active.
Think of it as the number of calories your body needs to use while you sleep.
The other way to measure metabolic rate is via the “total daily energy expenditure” (TDEE). This measures both the resting metabolic rate AND the energy used for “work” (e.g. exercise) during a 24-hour period.
What affects your metabolic rate?
A number of factors!
The first thing you may think of is your thyroid.
Remember, this gland is at the front of your throat. It releases hormones to tell your body to “speed up” your metabolism.
Of course, the more thyroid hormone there is the faster things will work and the more calories you'll burn and vice versa.
But that's not the only thing that affects your metabolic rate.
How big you are counts too!
Larger people have higher metabolic rates; but your body composition is crucial!
The more fat you have the lower your metabolic rate compared to someone who has more muscle.
Muscles that move and do work need more energy than fat does.
So the more lean muscle mass you have the more energy your body burns and the higher your metabolic rate will be.
This is even when you're not making a point of working out.
This is exactly why weight training is often recommended as a part of a weight loss program. Because you want muscles to be burning those calories for you.
The thing is, when people lose weight their metabolic rate often slows down. This is because there is less of you. Now of course you don't want that to happen.
The way to solve this decline is to have MORE muscle mass.
Aerobic exercise also temporarily increases your metabolic rate. Your muscles are burning fuel to move so they're doing “work”.
The type of food you eat also affects your metabolic rate.
Your body uses calories to absorb, digest, and process your food. It is called the “thermic effect of food” (TEF).
Since your body processes foods differently you can use this TEF to your advantage.
Fats, only increase your TEF by 0-3%. Carbohydrates increase it by 5-10%. Protein increases it by 15-30%.
By decreasing your intake of fats or carbs and increasing the amoutn of lean protein you eat, you can slightly increase your metabolic rate.
An added bonus of eating protein is that your muscles need it for growth. By working them out and feeding them what they need, they will help you to lose weight and keep it off.
And don't forget the mind-body connection.
There is plenty of research that shows the influence that things like stress and sleep have on the metabolic rate.
This is just the tip of the iceberg when it comes to metabolism and how so many different things can work to increase (or decrease) your metabolic rate.