Metabolism - what is it? And 5 ways to boost your metabolism to help reduce the belly fat

As midlifers we often want to know how to increase our metabolism to help us remove the weight around the middle. This blog looks at the best metabolism booster including lifestyle and metabolism boosting foods. It also includes five ways to get your metabolism helping your efforts to reduce belly fat.

Metabolism - what is it? And how to increase it…

This word “metabolism” is thrown around a lot these days.

And it was the very first question I got asked by a stranger not long after graduating as a nutritionist. I was at a wellness day and a lady came up to me, after finding out I was a nutritionist. Her question was – should she be taking apple cider vinegar or raspberry ketones to increase her metabolism? That’s a very specific question to kick off your nutrition career with!

If you’re looking to reduce your belly fat then you’re probably interested in whether you can increase your metabolism and you probably know that if yours is too slow you might gain weight.  But what exactly does this all mean?

Well technically “metabolism” is the word to describe all of the biochemical reactions in your body.  It's how you take in nutrients and oxygen and use them to fuel everything you do.

Your body has an incredible ability to grow, heal and generally stay alive.  And without this amazing biochemistry you would not be possible.


Metabolism includes how the cells in your body:

  • Allow activities you can control (e.g. physical activity etc.).

  • Allow activities you can't control (e.g. heart beat, wound healing, processing of nutrients & toxins etc.).

  • Allow storage of excess energy for later.

So when you put all of these processes together into your metabolism you can imagine that these processes can work too quickly, too slowly or just right.

Which brings us to the “metabolic rate”. 


Metabolic rate

This is how fast your metabolism works and is measured in calories (yup, those calories!).

The calories you eat can go to one of three places:

  • Work (i.e. exercise and other activity).

  • Heat (i.e. from all those biochemical reactions).

  • Storage (i.e. extra leftover “unburned” calories stored as fat).

In very simplistic terms, the more calories you burn as work or creating heat the easier it is to lose weight and keep it off because there will be fewer “leftover” calories to store for later. But remember, you can’t out-exercise a poor diet!

There are a couple of different ways to measure metabolic rate.  One is the “resting metabolic rate” (RMR) which is how much energy your body uses when you're not being physically active.

The other is the “total daily energy expenditure” (TDEE) which measures both the resting metabolic rate as well as the energy used for “work” (e.g. exercise) throughout a 24-hour period.


What affects your metabolic rate?

In a nutshell: a lot!

The first thing you may think of is your thyroid.  This gland at the front of your throat releases hormones to tell your body to “speed up” your metabolism.  Of course, the more thyroid hormone there is the faster things will work and the more calories you'll burn. And in this previous blog post I talked about how thyroid and other hormones are involved in weight gain, particularly belly fat.

But that's not the only thing that affects your metabolic rate.

How big you are counts too! 

Larger people have higher metabolic rates; but your body composition is crucial! 

As you can imagine muscles that actively move and do work need more energy than fat does.  So 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.

This is exactly why weight training is often recommended as a part of a weight loss programme.  Because you want muscles to be burning those calories for you. 

The thing is, when people lose weight their metabolic rate often slows down which you don't want to happen.  So you definitely want to offset that with more muscle mass. There’s often muscle loss along with weight loss so you want to try to minimise muscle loss and maximise fat loss. This is why just using weight as an indicator isn’t the best, because is it muscle, fat or just water that’s been lost?

Aerobic exercise also temporarily increases your metabolic rate.  Your muscles are burning fuel to move so they're doing “work”.


And the type of food you eat also affects your metabolic rate!

Your body actually burns calories to absorb, digest, and metabolise your food.  This is called the “thermic effect of food” (TEF).

You can use it to your advantage when you understand how your body metabolises foods differently. 

Fats, for example increase your TEF by 0-3%; carbs increase it by 5-10%, and protein increases it by 15-30%.  By trading some of your fat or carbs for lean protein you can slightly increase your metabolic rate.

Another bonus of protein is that your muscles need it to grow.  By working them out and feeding them what they need they will help you to lose weight and keep it off. I’m not saying a high protein diet is where you need to be, you just need to be having protein regularly throughout the day to stimulate muscle protein synthesis. Remember, protein is in a whole variety of foods and a varied diet is key. Try vegetable sources such as beans, lentils, tofu, nuts and seeds.

And don't forget the mind-body connection.  There is plenty of research that shows the influence that things like stress and sleep have on the metabolic rate. Again, this is key for midlifers where hormone imbalance can be a cause of belly fat and hormones are sensitive to stress and lack of sleep. This blog post discusses it further.

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.


5 ways to get your metabolism helping you reduce your belly fat

  • Keep your hormones happy – try to reduce the amount of refined sugars and processed foods in your diet and stick to complex carbs, decent proteins and some good fats.

Struggling to Ditch the Junk? Why not join my 5 Day Ditch the Sugar Challenge for extra motivation and support.

  • Get plenty of sleep. This can be a tough one during the week when there’s lots going on. I know a decent bedtime is often the thing that slips first for me but it has a knock-on effect the next day.

  • Try to reduce stress as much as possible – again another tough one to put into practise when there’s so many things to juggle. It can feel like you’re hanging on for the weekend in order to relax for two days and then do it all again. Try to factor in anything that will help – even if it’s a few deep breaths while the kettle boils.

  • Exercise! Try to include weights or activities that are weight bearing along with cardio exercise too. But choose something you enjoy. You’re not going to stick to a routine if you’re forcing yourself to do something you dislike.

  • Eat small amounts of protein throughout the day to keep your muscle percentage optimum. It’s a balancing act not to lose too much muscle while also trying to lose weight.

Content Disclaimer

The information contained above is provided for information purposes only. The contents of this blog are not intended to amount to advice and you should not rely on any of the contents of this blog. Professional advice should be obtained before taking or refraining from taking any action as a result of the contents of this blog. Midlife Menu Ltd disclaims all liability and responsibility arising from any reliance placed on any of the contents of this blog.