Metabolism Myths, Busted: What Actually Works

Article summary:

• Our metabolic system matters. It’s the engine that keeps our bodies moving, breathing, thinking and resting, 24 hours a day, 7 days a week.
• The higher your metabolic rate, the more calories you’re likely to burn. And the slower your metabolism, the more difficult it can be to lose weight and prevent weight gain.
• There are lots of myths and misconceptions around metabolism, and how to best support it. Fortunately, research continues to shed new light on the healthy habits that are worth implementing to support better metabolic health.

Metabolism Myths, Busted: What Actually Works

Every second, billions of chemical reactions are taking place within your body. [1]

We call this process metabolism, and your metabolic health is an important part of your overall wellbeing. If your metabolism's working too slowly, it can become harder to lose weight or prevent weight gain. [2]

We know it's in our best interests to support our metabolism however we can. But there are also a lot of myths and misconceptions around metabolism: how it works, what affects it and how you can increase your metabolic rate.

In this article we'll explore (and debunk) 5 common myths around metabolism. We'll also take a look at some of the latest research, to see which small daily changes may make a real difference to your metabolic health.

What is metabolism?

Metabolism is the process which converts your energy intake into your energy expenditure. In other words, it takes the energy you consume (from your food and drink) and turns it into the energy that fuels everything you do. From moving to thinking, sleeping and even regulating your hormone levels, none of the functions that power your body are possible without metabolism. And that's why taking care of your metabolic health is so important.

How does metabolism connect to weight loss?

Metabolism is all about balance (we call this metabolic homeostasis). And weight loss happens when your body uses more calories than you consume, because it starts using stored energy, including body fat, for fuel. [3]

Your body's metabolism is driven mainly by 3 things:

• Basal metabolic rate (BMR): This is the minimum number of calories your body needs to function (like breathing, and circulating blood around your body). It takes up around 60-75% of your daily calories. [4]
• Physical activity: This is the energy used for daily movement, both intentional (like exercise) and non-intentional (like fidgeting).
• Thermic effect of food (TEF): This is the energy used to digest and store the nutrients taken from the food we eat.

The higher your metabolic rate, the more calories you're likely to burn. [5] In contrast, if your metabolism is too slow, it can affect how well your body functions. This includes how your body manages things like blood sugar, which over time may increase the risk of conditions like type 2 diabetes. [6]

As we've seen, metabolism is fundamental for generating energy. But what you do with this energy affects how your metabolism works. Let's take a look at 5 common metabolism myths:

Myth #1: The more you age, the slower your metabolism

One common myth is that your metabolism starts to slow down once you hit your 30s. However, a recent large-scale study has provided some interesting, and perhaps surprising, insights.

The research revealed that energy expenditure from your 20s through to your late 50s is the most stable period of your life (including during pregnancy). And even from the age of 60 onwards your metabolic slowdown is gradual, at a rate of about 0.7% a year. [7]

So, while you may expect a gradual decline in your metabolism once you reach your 60s, it seems that age may not be a major factor in metabolic health before then.

Myth #2: Specific foods can "speed up" your metabolism

You may have heard that eating certain types of foods and compounds can "boost" your metabolism. While some, like caffeine, may temporarily raise your metabolic rate, they're unlikely to lead to significant long-term weight loss without additional lifestyle changes. [8]

It's also worth applying caution to certain types of diets. While lower-calorie diets which put you into a calorie deficit may support short-term weight loss, they should never be used as a long-term approach. Severely restricting your calories may cause your metabolic rate to slow, and can also negatively impact your overall wellbeing. [9]

Likewise, there's limited evidence to support the idea that eating smaller, more frequent meals supports your metabolic health. In fact, for some, doing so may increase hunger. [10] And skipping meals entirely may even make weight management harder. [9]

Not getting the nutrients you need can affect your physical and mental well-being. [11] If you, or someone you know, is experiencing disordered eating, help is available.

Myth #3: You can "make up" for poor sleep

Whether you're a shift worker, a caregiver or you simply find it hard to switch off at night, getting the recommended 7-9 hours of sleep a night can be a challenge. [12] However, over time, poor sleep quality can affect your metabolic health. And, unfortunately, you can't "make up" missed sleep by sleeping longer on your days off. [13] In fact, research has shown that chronic sleep deprivation can have a significant impact on your metabolism. [14]

When you don't get enough sleep, your levels of ghrelin (the "hunger hormone") rise and your levels of leptin (the "fullness hormone") decrease. [15] This hormonal imbalance signals false hunger to your brain, affecting appetite control and making you more likely to seek out calorie-dense food. [16] This imbalance between your fullness and hunger hormones can also cause your levels of cortisol (the "stress hormone") to spike. While certain types of short-term stress are not always a bad thing, chronic stress and higher cortisol levels may negatively affect your physical, as well as mental, wellbeing. [17] [18] This is, in part, because cortisol raises your blood sugar levels, driving insulin resistance (how your body controls your blood sugar). [19] Over time, insulin resistance may impact your metabolism and lead to conditions like type 2 diabetes. [20]

Myth #4: Cardio is the best exercise to improve your metabolism

Cardio workouts have been shown to support weight loss. [21] And when done safely and in moderation, exercises like high-intensity interval training (HIIT) may support heart health and also improve your insulin sensitivity. [22] [23]

However, to best support your metabolism it's recommended to incorporate a range of different exercises.

For example, strength training may help increase your metabolism. This is because strength training focuses on building muscle tissue, which is more metabolically active than fat and burns more calories (even when you're resting). [24]

When it comes to metabolic health, cardio certainly has its benefits. However, if you're either new or returning to exercise, a combination of low-impact cardio, gentle strength training and intentional daily movement is best to support positive health changes. [25]

Myth #5: You can't change your metabolism

There is an element of truth to this myth, as your metabolic rate is partly down to your genetics. [26] And there's no quick and simple way to "boost" or "speed up" your metabolism.

However, it is possible to make long-term lifestyle changes which support your metabolic health (we'll explain those in more detail below). By making small, sustainable daily changes (like improving our sleep quality, eating well and moving mindfully), you may be able to support weight management and improve your metabolic function.

How to support your metabolism

Now we've addressed some of metabolism's most common misconceptions, let's take a look at the evidence-based ways you can support your metabolism.

Diet

A balanced, varied diet will help to fuel your body and support your energy expenditure. Try to avoid skipping meals, and include these foods where possible:

• Protein: Protein helps keep you fuller for longer, and your body also uses more energy to digest it. [27] To best support your metabolism, try to add a good source of protein to every meal, like chicken, eggs, beans or tofu.
• Fibre: Foods which are rich in fibre, like lentils, take longer for your body to break down. This can help you feel full for longer and support healthy digestion. [28]
• Leafy greens: Foods like kale and spinach are rich in iron and magnesium, which support metabolic function. [29]

Hydration

Dehydration can slow your metabolic rate, so it's important to hydrate whenever you feel thirsty. [30] According to Dietitians of Canada you should aim to drink between 9-12 cups of water each day, but exact recommendations may vary based on factors like your age and physical activity levels. [31]

Your body can also sometimes mistake thirst for hunger signals, so it's worth drinking a cup of water when you first begin to feel hungry or crave a snack. [32]

Sleep

Sleep and metabolism go hand-in-hand. That's why improving your sleep quality is one of the most important ways to support your metabolic health. Health Canada recommends that adults aim for 7-9 hours of quality sleep each night. [12] Waking up and falling asleep at roughly the same time every day will also help to regulate your circadian rhythm (body clock). This is important for metabolic function, because your circadian rhythm helps to improve insulin sensitivity and keep your appetite hormones in check. [33]

Movement

While strength training and cardio both support metabolic function, any regular form of movement which raises your heart rate helps. [34] [35]

If you're returning to exercise, or just starting, it's better to focus on mindful movement. Start slow, and gradually build up your strength and stamina over time. You could begin by increasing your daily step count, or taking the stairs rather than the escalator (if possible).

If you'd like to try strength training, you could begin with gentle exercises which use either resistance bands or your own body weight to gradually build muscle strength. If you’re unsure if it’s safe for you to do exercise, always speak to your healthcare provider before starting any new activity.

Sustainable change takes time, especially when it comes to your metabolism. Find what feels right for you, and try to keep to a consistent schedule for long-term results.

Remember that the metabolic system is all about balance. And the best way to support it is to find balance and consistency in your daily routine. From the food and drink you use to fuel your body, to making sure you work mindful movement and rest into your day-to-day life, improving your metabolic health begins by making sustainable, positive lifestyle choices.

For more advice on how to improve your metabolic health, speak to your clinician or healthcare professional. And, if you're interested in learning more about how weight management treatments may support your health journey, our friendly team is here to help.

Find out which treatment may be suitable for you with MedExpress.

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