Weight loss and metabolism: What you need to know

As you age, your body is likely to change, too. There are a stack of reasons behind this, from the food you're eating, to how much exercise you're doing as well as your hormones and genetics.

But, one of the biggest factors that can influence your weight is your metabolism.

Your body has a unique metabolic rate that determines how quickly your body is able to burn energy. The interesting thing is that your metabolic rate isn't static, and can actually change as you progress through life.

It's safe to say that there is a lot to unpack when it comes to how your metabolism might impact your ability to lose weight. Let's dive into how your metabolism works, the role your metabolism plays in losing weight and some common FAQs about whether you can speed up a slow metabolism.

What is metabolism?

Let's start with the basics.

Your metabolism is a bodily, chemical process responsible for turning food into energy [1]. It can be helpful to think of your metabolism as how efficiently your body burns through calories. For some, your metabolic rate might be very fast (which means you burn through the foods and drinks you consume quickly).

On the flip side, you might have a slow metabolism that takes a longer time to process food for energy (meaning you burn fewer calories each day).

Your body needs vitamins, minerals, fats, carbs and protein to survive. So, your metabolism is an essential process that converts the foods you consume into energy that your body can use to function.

What is your basal metabolic rate?

The rate at which your body processes energy is known as your basal metabolic rate (sometimes referred to as your resting metabolic rate) [2]. As the name would suggest, this figure explains the minimum number of calories or kilojoules your body needs to survive. Usually, it takes into account basic bodily functions, such as breathing, circulation, digestion and cell production.

So, how can you figure out your BMR? The most widely accepted formula is known as the Harris-Benedict Equation, which uses your height, weight, age and gender to come up with your BMR [3]. There are stacks of interactive online tools that can help you figure out this rate, or you can use these formulas below:

• Women: BMR = 655 + (9.6 x weight in kg) + (1.8 x height in cm) - (4.7 x age in years)
• Men: BMR = 66 (13.7 x weight in kg) + (5 x height in cm) - (6.8 x age in years)

By figuring out your basal metabolic rate (BMR), you can get a ballpark figure of how much energy you need to be consuming each day to keep your body functioning.

What role does metabolism play in weight loss?

As you can probably tell, your metabolism plays a big role in your ability to lose weight. But it's also important to call out that it's not the only factor that influences your weight loss journey and your capacity to navigate weight gain.

First up, let's dive into exactly how your metabolism works [2]. There are two core components to your metabolism:

• Catabolism: a process where your body breaks down the food you consume into simpler forms that your body can use for energy.
• Anabolism: another type of process where your body uses this energy to grow and repair different cells throughout your body.

The other important thing to know about your metabolism is this: if you consume more energy (a.k.a. food) than you need, it'll typically be stored in your body as fat.

With that in mind, your metabolism plays an important role in regulating your body fat levels and influencing your capacity for weight gain. But the equation is a lot more complicated and nuanced than simply calculating how many calories you consume versus how many calories you burn on a daily basis.

First up, research has shown that the human body is hard-wired to slow down your BMR if your body isn't consuming enough calories or energy [1]. It's a biological response to prevent starvation, which means that simply eating fewer calories won't instantly equate to losing weight.

Plus, your genetics have been shown to play a big role in whether your body is predisposed to weight gain or weight loss [4]. Your genetics have the power to influence your appetite, your food cravings and even your ability to feel full between meals. For some people, their genetics account for up to 80% of their predisposition to become overweight [4].

With that in mind, it's important to remember that your metabolism and metabolic rate isn't the only thing determining your weight management.

Can you speed up your metabolism?

Unfortunately, most of the research points to no.

Over the years, there have been stacks of foods, drinks and fancy diet products that were claimed to increase your metabolism (from chilli pepper to coffee and even radical crash diets). However, there is little scientific evidence to back up these claims.

That's because your metabolism is influenced by factors that are hard to change or influence such as your gender, age and genetics.

Some research has shown the benefits of exercise in increasing your body's lean muscle mass (which can help your body burn more calories). While there's little evidence to suggest an increase in exercise changes your metabolic rate, it's clear that increasing your daily movement can help you to burn more energy.

Why does your metabolism matter?

Your metabolism plays an important role in your body's composition and your ability to lose weight [5]. It's clear that your basal metabolic rate is what is largely accountable for how much energy your body needs. If you're looking to lose weight or prevent weight gain, knowing how much energy you should be consuming on a daily basis can help you hit your weight goals.

How does menopause impact metabolism?

Menopause is a major life event for many women. But, what is the relationship between menopause and your metabolism?

Research has shown that age is a key factor in how efficiently our metabolism works. As you progress in life, your metabolism slows down, which can increase your chance of weight gain [6].

But your metabolic rate isn't the only factor that can lead to a change in weight during menopause. Some of the other factors that can cause weight gain during menopause include:

• Hormonal changes: Oestrogen levels are shown to drop during perimenopause and early menopause, which has been shown to lead to the body storing excess weight and fat in the abdominal area [6]
• Reduced physical activity: As you navigate the physical symptoms of menopause (such as sleep problems and mood changes), you might notice a decline in your exercise levels. This can reduce your lean body mass and increase your likelihood to gain weight
• Genetic or family history of obesity: Your genes play one of the biggest roles in whether or not you gain weight as you age (or navigate life stages such as menopause)

What other factors can impact your metabolism?

Whether you're navigating menopause or not, there is a range of metabolic disorders that can influence your capacity to lose weight [7]. These include:

Thyroid disorders

Your thyroid contains glands that are responsible for regulating your hormone levels. An underactive thyroid occurs when your body isn't releasing enough hormones to support a healthy metabolism.

An overactive thyroid, on the other hand, means your body is overproducing these hormones (which can speed up your metabolism).

Fructose intolerance

This genetic disorder means your body isn't able to process the type of sugar found in fruits and some vegetables.

Galactosaemia

This is another genetic disorder that can impact your metabolism. It occurs when your body isn't able to convert carbohydrates into glucose effectively.

What you need to know about weight management

As you progress through life, changes in your weight are expected. But, it's also important to know your options and make informed choices about how to combat weight gain if it does happen.

The key is to look for sustainable, holistic weight management strategies that can help you tackle the root cause of weight gain and keep it off for the long term. That means:

• Eating a balanced, healthy diet that provides all the vitamins and minerals you need, while still giving you the flexibility to eat out and enjoy the foods you love in moderation.
• Prioritising daily exercise and finding a style of movement that you enjoy (whether that's swimming, walking, cycling or even gentle yoga or Pilates).
• Do your best to get a good night's sleep each night to ensure your body is able to rest and recover properly.

If you're not finding success with lifestyle changes alone, it might be worth considering a comprehensive weight management programme, like Juniper's Weight Reset Programme.

Juniper’s Weight Reset Programme combines proven weight loss medication, health coaching and ongoing support to help you lose weight and keep it off. We prescribe a GLP-1 medication called Wegovy, which contains the active ingredient semaglutide.

Semaglutide is clinically proven to reduce your appetite and make you feel fuller for longer, while also reducing cravings by targeting the rewards centre in the brain.

For long-term success, changing your eating and movement habits is also crucial, which is why we offer a comprehensive programme that includes 3 core pillars of lifestyle change with the assistance of our UK clinicians.

We can help you break habits that might be impacting your weight and help you hit your weight loss goals sooner.