What is metabolism and can you speed it up?

You will often hear people blame a slow metabolism for gaining weight.

But in truth, there is a lot more to weight management than the speed of your metabolism.

In fact, a slow metabolism is rarely to blame for weight gain.

So what is metabolism? And is there any way in which you can speed it up?

What is metabolism?

Metabolism refers to all of the chemical processes which happen inside your body to keep you alive.¹

This takes energy, which is converted from everything you eat and drink.

In this continual process, the calories from our food and drinks are combined with oxygen and this releases the energy that your body needs to function.²

Even whilst your body is still and at rest, it is still burning calories in order to perform the basic functions that keep us alive.

These include breathing, circulation, nutrient processing and cell production and repair.³

Basal Metabolic Rate (BMR)

The number of calories that your body needs to perform the basic functions which keep us alive is known as the basal metabolic rate (BMR).

Your resting metabolic rate (RMR) is the number of calories that your body burns while it is resting.⁴

When we talk about a slow metabolism, it might be more accurate to say that we have a low BMR.⁵

What factors determine how fast your metabolism is?

Your metabolic rate can be determined by a number of factors.

These include age, gender, muscle-to-fat ratio, the amount of physical activity that you do and hormone functions.⁶

Muscle-to-fat ratio

If you are larger or you have a lot of muscle, you will burn more calories than someone who is smaller. This is true even at rest.

Gender

Men tend to have less body fat, heavier bones and more muscle mass than women of the same age and weight.

This means that men burn more calories since muscle tissue is more active and burns more calories than fat, even whilst doing nothing!⁷

Age

Usually as you get older, the amount of muscle that you have decreases and more of your weight is made up of fat. So advancing years really do slow down calorie burning.⁸

Genes

It is thought that your genes may be a factor in determining how fast your metabolism is, although there is not enough research yet to fully understand why this might be.

What we do know is that genes play a role in the size of your muscles and your ability to grow muscles. And that this has an effect on your metabolism.⁹

Can you speed up your metabolism?

There are a few things you can do to help stimulate your metabolism and burn off more calories.

These things revolve around eating a healthy balanced diet and leading an active lifestyle:

Be more active

The more active you are, the more calories you will burn.

Effective ways of staying active include aerobic activity such as walking, cycling or swimming; strength training like lifting weights and high intensity exercise; and making lifestyle changes, such as taking the stairs instead of the lift as well as cycling to work.¹⁰

Eat a healthy balanced diet

As well as being more active, there are some changes you can make to your diet which could help your metabolism.

Foods that help burn fat include:

• Oily fish which contains omega-3 fatty acids
• Caffeine from coffee
• Eggs which are a great source of protein, which increases your metabolic rate¹¹  
• Coconut oil, which is made up of medium-chain triglycerides which are rapidly absorbed by the body¹²

Drink more water

Drinking water can temporarily speed up your metabolism, with studies showing that drinking just 0.5 litres of water increases metabolism by 10-30% for around an hour¹³

If you drink cold water, your body also uses energy to heat it up to body temperature, therefore burning more calories¹⁴

Drinking teas

Slimming teas may help to stimulate digestion and aid metabolism.

For example, green tea has been shown to speed up metabolism by 4-5%.¹⁵

As well as this, green tea can convert some of the fat stored in the body into free fatty acids, which can increase fat burning by up to 17%.¹⁶

Making some of these lifestyle changes to live a more active lifestyle and eat a healthier diet may help to speed up your metabolism, which in turn can help you to lose weight too.

Last updated: 17 March 2021