Why Is My BMR So Low? (5 Explanations And What To Do)

Here’s what you need to know if your BMR is low, including explanations, what to do and whether you should be concerned or not.

By Robin White

Reviewed by Brian Richards, CPT, CSCS. Last updated 16th December.

Key Takeaways

It’s important to fully understand what BMR actually is (i.e., the calories you burn before you perform any physical activity). This is different from your TDEE (Total Daily Energy Expenditure) which includes physical activity.
There are several factors that influence BMR and metabolism. If you have serious concerns, consult a professional healthcare professional.
Some common causes for low BMR include: lack of sleep, bad diet, hormones, medications, eating disorders, genetics, and sedentary lifestyle.

Many fitness trackers and diet apps allow you to calculate your BMR – but what happens if it is showing a low BMR score?

Should you be worried? Is it normal? Is this good for weight loss?

There are probably a lot of questions you’ve got, so the aim of this article is to provide a clear and concise overview of what a low BMR score means.

Your BMR, or Basal Metabolic Rate, is a term that describes the energy you use just to exist, without any additional movement or activity. This means your TDEE, Total Daily Energy Expenditure, is going to be much higher – and this metric is a better indicator if you are trying to calculate how many calories to consume to lose weight in a calorie deficit.

Below, I’ll show you how to accurately calculate your BMR, the likely reasons why you’ve got a low BMR, whether this is a cause for concern and ultimately, what you can do to increase your BMR.

What Is BMR?

BMR (Basal Metabolic Rate) is the number of calories or energy your body burns when you’re resting. This set number of calories is what it takes to keep your body running when you are not doing absolutely anything.

The body needs to spend energy, even if you are not moving around. This energy keeps you running — while you’re sleeping, for example, your body is still doing a lot of work. Your body can consume up to 70% of the calories you intake daily just to work properly.

Knowing your BMR is also important when you want to lose weight. The rate at which your body burns calories dictates how many calories you can consume and still lose weight. So, the higher your BMR is, the more calories you can consume.

Muscles spend more calories than fat, so people with more muscles burn more calories. If you increase your level of activity, you’ll burn more calories too — and your BMR will be higher as well.

Another important factor here is your metabolic age. Your BMR will rise as you age from a child up to the late teenage years, when it will stop and start to decrease. If your BMR is low, this means you have to eat fewer calories to lose weight. When calculating your BMR, it’s important to include your age because that also dictates the number of calories you can consume.

What is a “Low” BMR?

A low BMR will mean different things to different people, for example, even your height may influence where your BMR sits on a “general” BMR scale of the population.

As a general guideline, an average BMR is seen somewhere between 1400-1800 (1400 for women, and 1800 for men).

This means anything lower than that range, could be considered a “low” BMR.

How to Calculate Your BMR

You’ve probably already used an online calculator to see what your BMR is. This is the simplest and cheapest way to find this out, but all of these calculators use a basic formula. They will give you the right results based on your measurements, age, gender, and level of activity.

Here are the formulas these calculators use:

Men: 66 + (6.23 x Your Weight in lbs) + (12.7 x Your Height in Inches) — (6.8 x Your Age)

Women: 655 + (4.35 x Your Weight in Lbs) + (4.7 x Your Height in Inches) — (4.7 x Your Age)

The number you get will signal your BMR or how many calories your body burns with zero activity. However, we all move around and perform some sort of activity every day, so you need to calculate that as well so that you can know how many calories your body needs in total.

Here are some guidelines:

If you don’t exercise much besides regular daily activities, multiply your BMR by 1.2

If you exercise 1 to 3 times every week, your BMR should be multiplied by 1.375

If you work out 3 to 5 times a week, you should multiply your BMR with 1.55

If you work out 6 to 7 days a week, your BMR should be multiplied by 1.725

If you work out daily and have a physical job (this includes people who exercise two times daily), your BMR should be multiplied by 1.9

The number of calories you get in this calculation is the number of calories necessary for you to maintain your weight. If you want to lose weight, you have to eat less than that.

What Causes Low BMR?

If you calculated your BMR and it’s lower than you thought, you might be wondering what caused that. Well, there are a few mistakes you might be making that are keeping your metabolism slow. Here are some of them:

Eating a low amount of calories. While it may seem strange, eating less makes your metabolism slower (and thus slows down any weight loss). If your goal is to lose weight, you’ll need a calorie deficit, but only in reasonable amounts. When your body realizes that you are eating less, it starts burning calories slower to ensure it has more energy for later.

Not eating protein. Protein helps you feel full, and it can also speed up your body’s calorie consumption. It has a thermic effect that is higher than other nutrients, and eating protein helps increase metabolism. Inevitably, your metabolic rate will slow as you lose weight, but you’ll make that effect less significant if you consume more protein.

Being sedentary. If your work is mostly sitting, your metabolic rate is likely to slow down. You’ll burn fewer calories. Even the simplest tasks like cleaning the house or walking could help you reduce that effect, especially if most of your time is spent without significant activity.

Lack of sleep. Not sleeping enough is known to cause many health issues, but it can also slow your metabolism down. A lack of sleep will cause you to lose weight at a slower rate, and it can introduce numerous other problems. Sleeping during the day and being awake at night is also bad for you, and it slows down your metabolic rate as well.

Sugary drinks. You probably already know that these are bad for you, but did you know that they can also slow your metabolic rate down. Aside from that, sugary drinks introduce a large number of empty calories to your body, and they don’t have anything useful while making you gain weight.

What to Do if Your BMR Is Low?

When people ask about how to boost their BMR, there are often many recommendations on what to eat or drink, based on anecdotal evidence (in translation: a friend of a friend tried this, and it worked). The problem with that is that each person is unique and what possibly worked for someone might not work for you.

Common recommendations include caffeinated drinks like coffee or green tea, but there are others like energy drinks or spicy food. Medical evidence only vaguely mentions that these could work, but they are not a magical solution.

BMR is pretty hard to control, and it depends on numerous factors. While increasing it is unlikely, you can control how many calories you burn every day. And this comes only through physical activity.

People whose BMR is higher probably just have more activity in their day, whether through work or exercise. In that spirit, here are some ways you could boost your daily calorie burn:

Strength training. More than any other activity, strength training can help you burn more calories. What’s more, it can help you burn more calories even when not doing anything simply because you’ll have more muscles and less fat. Muscles burn more calories. You should do this at least twice a week — lift weights, do high-intensity training, etc. Even some regular activities like heavier gardening could help.

Aerobic training. Another form of exercise that will give your BMR a boost is aerobic. And it doesn’t have to be an every-day thing. You just need to do 150 minutes of aerobic activity weekly, and you’ll see the benefits. Aerobic activities you can do with ease are walking, swimming, or even cycling. Naturally, if you want to lose weight, you’ll need to do more.

Move around. You don’t have to exercise specifically, but you do need to stay active on a daily basis. For example, walk to work or ride a bike, avoid elevators and use stairs, move around when you’re home, run with your dog, etc. Every movement is beneficial, and it will help you burn calories quickly.

Eat More. (Make healthy choice the easy choice)Spinach…B vitamins…

Sleep More (Cortisol…

Summary

As you can see, a lack of activity and poor food choices can lower your BMR, and only more activity and better food can fix that. Try to introduce some basic, fun activities into your life, like a dancing session in your living room to your favorite songs or a bit of gardening. Any activity makes a difference.

Consume healthy food and stay away from sugary beverages, junk food, etc. Remember that there’s no magic pill for metabolism speed or weight loss — no matter what shady websites tell you — so you have to put in some work. Good luck!