We hear a lot about metabolism nowadays, and it's usually in the context of weight, often speaking of slow and high metabolisms. There are a lot of factors that go into individual metabolisms.

They can be genetic and related to lifestyle and activity levels, but one thing for sure is that metabolism can be improved just as it can be slowed. 

What is Metabolism?

In short, it’s a blanket term that covers every chemical reaction in your body. Furthermore, it’s the metabolic process of combining oxygen and calories the body uses to release energy. 

This means that metabolism is responsible for:¹

• Breathing 
• Digestion 
• Cell growth and repair 
• Hormone regulation and management 
• Temperature regulation

So, metabolism is not all about weight; metabolism is responsible for almost every aspect of human life.

Metabolism is also interchangeable with the more scientific term metabolic rate, meaning the number of calories necessary to maintain, lose or gain weight. You can do many things to change your metabolic rate to achieve your desired goals.

Furthermore, fast metabolism isn’t always associated with being “thin”, as studies have shown that medically overweight people often have fast metabolisms, and their bodies require more energy to keep their essential functions running.²

Eat More Protein 

Increasing protein in the diet isn’t only for bodybuilders and those who go to the gym daily. Protein is essential for the well-being of every individual regardless of activity level. 

Many studies show why higher-protein diets can be beneficial for metabolic control. Protein is the most satiating macronutrient, with research concluding that a 68% protein meal was much more satiating than a meal with only 10% protein.³

This means you will feel fuller for longer as your body has to try harder to digest the protein.

It has also been found that higher-protein diets increase diet-induced thermogenesis, which is the metabolic rate after the ingestion of food. When compared with high-fat diets.⁴

High-Intensity Interval Training (HIIT)

HIIT has had a lot of coverage in the fitness world over the past decade, and for a good reason. It is not only a practical and great workout, but it’s also great because it's less time-consuming for those with a busy lifestyle. 

It helps kickstart the body into new adaptation because it is an intense form of exercise. It has a profound impact on metabolism.

The body has a few choices in what to burn for energy, be it the food consumed, carbohydrates or the body fat of the individual. Studies have shown that HIIT helps the metabolism switch to burn fat over other sources.⁵

Nourish Your Gut Microbiome 

It's becoming increasingly well-known just how important the gut microbiome is to overall health. With more research daily examining the gut's role in previously unknown functions such as skin health and brain health, it's no surprise that the gut plays a crucial role in human metabolism. 

The gut and human metabolism are heavily interlinked. This is due to the signalling between the gut and the brain to keep the body and its functions running smoothly. So, in short, if your gut isn’t healthy, it can be setting off the wrong signals. 

Since the gut plays such a key role in metabolic processes such as glucose tolerance, fat storage, appetite and insulin sensitivity, it is always best to ensure that your gut is fully nourished.⁶

Heavy Weight Training 

Studies have indicated that resistance and strength training have a hugely beneficial effect on human metabolism, and this could be since muscle is much more metabolically active than fat, meaning that more calories are burned even when in a resting state.

Often when individuals attempt to lose weight, they end up in a caloric deficit and lose muscle. Strength training while trying to lose weight means that the muscle is retained, and the metabolism is boosted, which is better for the individual's overall health.^7,8

A study found that those on a calorically restricted diet with no exercise all lost weight. Still, those who did resistance training after the diet was over were able to maintain their muscle, metabolism and strength. Those that didn’t still lose weight but also lost a lot of muscle and significantly decreased metabolic rate.⁹

Green Tea 

Green tea is a great way to influence metabolism and several other benefits. It is known that green tea contains polyphenols which are well researched as being beneficial to the gut microbiome and aiding with metabolic issues.

It's well known that gut health is intertwined with metabolism and overall health. Still, green tea contains caffeine, which is well researched in increasing heart rate and energy expenditure and reducing appetite in individuals.^10,11

Increase Sleep Quality 

Sleep quality is something that every individual should be seeking to improve. Sleeping is something we all must do to survive, and it plays a crucial role in our daily bodily functions and mood.

Due to the increase in the use of technology and blue light from screens, there has been a massive increase in sleep disorders in the past decade, and this could be impacting our metabolisms.¹²

Studies have shown that sleep deprivation directly correlates with altered glucose metabolism and is linked to weight gain in individuals. This could be linked to the fact that lack of sleep increases ghrelin (the hunger hormone) and decreases leptin (the fullness hormone).^13,14

So, improving sleep quality can boost your metabolism or bring it back to stasis. 

Eat More Spicy Foods

Eating more spicy foods can be beneficial in a lot of ways. For one, eating more varied spices in your diet can improve your gut health and microbiota diversity, which positively impacts metabolism.¹⁵

However, here we are talking more specifically about capsaicin, the thing in chillies that makes your tongue tingle and also has a thermogenic effect on the metabolism.

Studies have shown that at the correct dose, eating hot chilli peppers in a meal would help burn 10 calories of that meal in digestion, which may not sound like a lot, but over time this can begin to add up.¹⁶ 

Drink Coffee

If green tea isn’t to your taste, you can get similar benefits from coffee. Studies show that caffeine in coffee can boost metabolism by 8% to 11%.¹⁷

Caffeine also contains polyphenols which are great for your gut and have a proven impact on the health of the gut-brain axis. Let's not forget that a healthy gut means healthy metabolism or a healthy gut means healthier overall.¹⁸

Eat More Whole Foods

The world is abundant with highly palatable ultra-processed food. There’s no denying that they are delicious; after all, they are designed to be delicious.

However, we must remember that everything is ok in moderation as food is about more than nutrition; it's about enjoyment too. However, eating too many processed foods can harm the gut microbiota and your metabolism.¹⁹

Swapping over to whole foods or including them in your diet gives your gut bacteria a challenge, as they are harder to break down. A study also showed that in whole foods versus processed foods, the energy expenditure post-meal was 50% less for processed food.²⁰

The Bottom Line

The recurring theme here appears that the simplest way to boost your metabolism is to start with the gut. It's worth mentioning that weight loss shouldn’t always be a focus unless your doctor states that it is urgently necessary for your wellbeing. 

Fixing gut health should always be a priority in losing excess weight as it encompasses brain health, physical health and metabolism, meaning that overall health is then accounted for.