Your basal metabolic rate (BMR) is the amount of energy your body needs to keep its essential functions going while you are at rest. That covers things like breathing, your heartbeat, brain activity, keeping your temperature steady and running your internal organs. BMR is measured lying down, in the morning, on an empty stomach, at a normal body temperature and in comfortable surroundings. It varies from person to person depending on age, sex, weight, height and muscle mass. Men tend to have a higher BMR because they usually carry more muscle. Illness, certain medicines and changes in lifestyle can all affect how much energy your body needs too.
How much energy do you need each day?
On top of your BMR, you use energy for movement, work and digesting food. How active you are is known as your physical activity level (PAL), and it makes a big difference. Two people of the same weight can have daily energy needs that differ by hundreds of calories, simply because one is far more active than the other. Your total daily energy expenditure is your BMR plus the calories you burn through activity and processing food. For most people, BMR alone makes up the majority of that total, usually somewhere between 60% and 75%.
Does a higher BMR make weight loss easier?
A higher BMR means your body burns more calories at rest, which can make managing your weight a little easier. A lower BMR can make losing weight slower. There is a common misunderstanding here, though: people who are very overweight often have a higher BMR, not a lower one, because a larger body needs more energy to run. When calories are cut sharply, the body tends to adapt by slowing its resting metabolism to conserve energy. This slowdown is usually temporary, but it is one reason why very strict dieting often backfires.
How to increase your basal metabolic rate
There are a few natural ways to give your BMR a lift:
- Build muscle through regular strength training
- Move more during the day
- Eat a balanced diet with enough protein
- Get enough sleep, which helps your body repair and recover
- Keep stress in check, since long-term stress can lower your metabolism
Together, these help your body use more energy even while you are resting.
What happens when your BMR drops too low?
Eating far fewer calories than your body needs can bring your weight down for a while, but it also slows your metabolism. Very low intake can reduce muscle and, in more serious cases, put strain on the heart, kidneys, liver and other organs. When normal eating starts again, that slowed metabolism makes it easy to regain the weight quickly, which is the familiar yo-yo pattern. During a very strict diet the body adjusts to running on less, so once the diet stops it burns less energy at rest and the weight tends to come back.
The healthy way to lose weight
The way to avoid the yo-yo pattern is to lose weight slowly and steadily, with the right support. The aim is to give your body enough energy for its BMR and daily activity while bringing your weight down gradually. Working with a doctor or registered dietitian helps you do this safely, so the results last. They can set a calorie target that suits your body rather than one that leaves you running on empty.
