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The word “metabolism” gets thrown around a lot these days. Or maybe I’m just hyper-aware because I’m currently struggling with a slow metabolism thanks to my Hashimotos.
If you’re like me and have a slow metabolism, you’ll know because you will probably start gaining weight, even if you’re doing all the “right things” like eating right and exercising.
What Is “Metabolism?”
Technically “metabolism” is the word to describe all of the biochemical reactions in your body. Let that sink in for a moment.
In other words, metabolism is how your body takes in nutrients and oxygen and uses them to fuel literally everything you do.
Because of this, your body has the incredible ability to grow and heal. In fact, without metabolism, you would be here.
Metabolism indicates how the individual cells that make you, well, YOU:
- Tolerate and use physical activity;
- Manage heart beat, wound healing, processing of nutrients & toxins, etc.; and
- Store excess energy for starvation periods or later use.
When you put all of these processes together, you get what makes you tick. Obviously everyone is different, and because of our different chemical make ups, your metabolism can work too quickly, too slowly, or just right. We’re all shooting for “just right” here. Kind of like Goldilocks.
Which brings us to your metabolic rate.
Metabolic rate is how fast your metabolism works and is measured in calories (yup, those calories!).
The calories you consume will go to one of three places:
- work (exercise and other activities),
- heat (from all those biochemical reactions), or
- storage (otherwise known as fat).
Obviously the more calories you burn for either work or heat the easier weight loss is because there are simply less “leftover” calories to send to storage.
Measure Your Metabolism
There are a couple of different ways to measure metabolic rate. One is your “resting metabolic rate” (RMR). This measures how much energy your body uses when you are not active.
The other is your “total daily energy expenditure” (TDEE). TDEE measures both the resting metabolic rate as well as the energy used for “work” throughout a 24-hour period.
What Effects Your Metabolism
Want to know a secret? A whole lot of things effect your metabolism.
First up is your thyroid. You may recall that your thyroid is a butterfly shaped gland at the front of your throat. Your thyroid releases hormones that tell your body to “speed up” your metabolism. If your thyroid isn’t functioning optimally (like with Hashimotos or Grave’s Disease), this doesn’t happen…or it happens too much.
The more thyroid hormone there is the faster things will work and the more calories you’ll burn. If you feel like you are gaining weight faster than you should be, or if you are losing weight and nothing you seem to do is keeping it on, you need to make an appointment with your doctor or naturopath to get your thyroid checked.
But that’s not the only thing that affects your metabolic rate. Body composition matters. It sucks, but it’s the truth.
Basically, the more muscle you have, the higher your metabolic rate.
Muscles that actively move and are constantly working naturally need more energy than fat does (because honestly, what on earth does fat do but lay around your body?). The more lean muscle mass you have, the more energy your body will burn, and the higher your metabolic rate will be. Even when you’re not working out.
Weight Training & Metabolism
This cause-effect marriage is why strength training is almost always recommended as a part of a weight loss program. Your muscles will burn calories for you, but only if you build them.
Oddly, when you lose weight your metabolic rate may slow down. Obviously this is something that you don’t want. But, if you have lean muscle mass (because you’ve been strength training), then you have a better chance at keeping your metabolism burning at a higher rate.
Unlike strength training, aerobic exercise temporarily increases your body’s metabolic rate. Basically, your muscles are burning fuel while they’re moving. They’re working.
Food & Metabolism
Your body actually burns calories to absorb, digest, and metabolize your food. This is called the “thermic effect of food” (TEF). Now, this does not give you license to go eat a pint of ice cream and call it ‘exercise’, even if it is Halo Top or Arctic Zero.
Understanding how different foods effect your body’s metabolism is key to eating in a way that will encourage a healthy weight (and a healthy burn).
Fats, for example, increase your TEF by between 0 and 3%; carbohydrates increase it by 5 to 10%; and protein increases your TEF by 15 to 30%. By trading some of your fats or carbohydrates for lean protein you may be able to slightly increase your metabolic rate.
Plus, your muscles need protein to grow. Working them out isn’t enough. You need to feeding your muscles what they need to help you to lose weight and keep it off.
Now, 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.
Which metabolic fact most surprised you?