As you know, metabolism and weight loss are deeply intertwined.
My last post was all about how to raise your metabolism but in fact I realize it just raised more questions 🙂
“OK, metabolism can cause overweight, but again, what is it exactly?”
“How do I know if I have a slow metabolism?”
OK, let’s step back and answer these questions.
What is the Medical Definition of Metabolism?
Said in easy words, metabolism is the minimal energy required daily by your body to survive.
Now the medical definition :
The Basal Metabolic Rate (BMR) is the energy required by your vital organs when your sympathetic nervous system is not stimulated. It is the minimal energy expended by your lungs, heart, liver, kidneys, skin, muscles etc. when sleeping.
The Resting Metabolic Rate (RMR) is just the same measure but at rest, not when sleeping.
How Do You Measure Metabolism?
The unit of measure is calories, as Basal and Resting Metabolic Rates measure energy.
In common words, they represent the minimum number of calories burnt per day to cover your vital functions. Your basal metabolic rate represents approximately 70% of the total number of calories burnt daily.
What is the Link between Metabolism and Thermogenesis?
Thermogenesis is the consequence and metabolism is the cause.
Your body requires energy for its basic functions and consuming this energy produces heat: this process of heat creation is called thermogenesis.
Let’s picture this: if your body was a house with a nice fireplace inside, metabolism would be the number of wood logs required to keep your house warm, and thermogenesis would be the fire burning the logs and producing heat.
Any Idea of Your Own Metabolic Rate?
We have several medical surveys that measure metabolic rates based on weight, height, age and sex. Based on that, you have many online tools that will do the guess work for you. You just have to enter these values (your weight, age etc) and you get a fair approximation of your BMR. Careful though: some sites don’t mention if they estimate your Basal Metabolic Rate or your Resting Metabolic Rate, in that case run and try other ones 🙂
Metabolism and Weight Loss: Why Should You Care?
It’s important since it will give you an idea of your minimum energy needs per day. Thus, you can compare to your calories taken in food and beverages and realize what is burnt and what is stocked as fat for future usage (in theory).
Is Metabolism Linked to Fat?
There are several aspects in this question:
Your fat mass plays a role in your metabolic rate, but fat cells (adipocytes) require very few calories to keep alive, compared to your lean body mass which is much more active and which burns many more calories.
That’s why you always hear that it is important to keep your muscle mass, because it will burn many calories even at rest, where fat cells could be stocked for years at very low cost of energy.
As a consequence, your fat mass will increase you metabolic rate, but in a low proportion.
In other words, you will need more calories to stay fat! Your food intake will be used to cover higher energy needs (your metabolic rate plus your daily activity) and as usual, the surplus will be stocked as fat in your adipocytes.The only way to break this vicious circle is to destock fat.
This brings me finally back to my previous post: how to raise your metabolism in order to lose weight. I hope that these explanations gave you a better understanding of this key physiological process, metabolism. From my experience, knowing how your body works is a crucial step to your overall health.