What in the World is a Basal Metabolic Rate, and Do I Have One?
In “Start Here, Start Now” I revealed a revolutionary formula for weight loss:
If you burn more calories than you take in, you will lose weight.
Did you feel the Earth move?!? Me either.
No, it’s not earth-shattering because you’ve heard it a thousand times before. And while it’s true, that doesn’t make it any easier to swallow.
But have no fear! Over the last seven years of my own weight loss and maintenance I have learned about a bazillion strategies for making that fact more tolerable.
There are three parts to this formula that we’re going to talk about this week. Yesterday was part one:
The second part of the formula is:
Know your basal metabolic rate.
“Huh? What in the world is a basal metabolic rate, and do I have one?!?” you’re asking.
Ah, I’m so glad you asked!
As a matter of fact yes, you do have one. And it’s a darn good thing too, otherwise you’d be a corpse. Your basal metabolism is the number of calories your body needs to perform basic functions each day; the ones that you’re doing without exerting any energy to do them: breathing, creating new cells, growing hair, controlling body temperature, circulating blood. No, you don’t get to count that as a workout. If your body would do it when you’re in a coma, that’s basal metabolism.
Your basal metabolic rate (BMR) makes up about 60-75% of your total calorie burn for the day, so whoooo hooooo! Less work for us to do!
BMR is affected by several factors:
- Lean Muscle Mass – This is where that adage “muscle burns more than fat” comes in; muscle, in fact, burns about 3-5 times as many calories as fat.
- Age – Totally unfair, but just like everything else, your BMR slows down as you age.
- Weight – The more you weigh, the more you burn. Think about it: you’re moving more mass (sorry, nothing personal) so it takes more energy.
- Sex – No, not frequency; your gender. Geez. Men have a distinct advantage here because of that whole muscle mass thing. Female BMR is 5-10% lower. Boo.
There are several secondary factors that influence your BMR:
- Hormones – Menstrual cycles, pregnancy, menopause. If you have concerns about how these impact your ability to lose weight, talk to your doctor because you’re right; they do.
- Thyroid function – An improperly functioning thyroid can throw off your metabolism by 30-50% so if you suspect this may be an issue for you, talk to your doctor and consider having it tested.
- “Starvation” or yo-yo dieting – Under no circumstances ever go below 1,000 calories a day (if fasting is part of your religious practice, make sure your doctor knows about it). If your body perceives that it is starving your metabolism can slow down by 50% or more! Do Not Do This!!! Your body needs fuel to make it run properly. We just need to figure out the right fuel to give it.
Try a couple (or more) BMR calculators online to get an idea of what your BMR is. Here are some to start with:
I’ll warn you, this is not an exact science. I got different numbers, albeit close, from each source. Still, I think I have a pretty good idea what my number is. Also remember, this is not your target calorie intake for the day! This is how many calories your body needs to perform basic functions. We’re gonna figure out your calorie range tomorrow, so don’t go anywhere!
You’re not imagining it: losing weight is hard. But it gets easier, I promise. And you’re so damn worth it!
Let’s go get it!