What Does Thermogenic Fat Burner Mean?

Lucy Bell-Young

by Lucy Bell-Young

23rd June 2021

Thermogenic fat burners are supplements that say they will increase your metabolism and help you burn fat. In the body, the process of burning fat generates heat, which is why these types of supplements are referred to as thermogenic. 

What is a Thermogenic Fat Burner?

In a nutshell, thermogenic fat burners help the body metabolise fat more effectively. Thermogenic fat burners spilling out of pill bottle with measuring tape

Sugar in the form of glucose is the primary source of energy in the body, and is used in all its metabolic processes. Whether you’re sleeping, awake, or running, you’re constantly consuming energy. However, the energy you consume in the form of the calories you burn might not be sufficient to counteract your body’s accumulation of fat.

Fat is relatively easy to store for many people, but it is notoriously hard to burn. Unless you commit yourself to intermittent fasting, a low calorie diet, and regular cardiovascular exercises, burning fat can be a slow process.

If you don’t have the time or willpower to diet or exercise but you still want to lose weight, thermogenic fat burner products might be something to consider after proper consultation with a qualified doctor.

Thermogenic, or thermogenesis, refers to the production of heat by the body. Fat becomes easier to burn as more energy is consumed by the cells. In this way, fat itself becomes a source of energy. The more energy is used, the more fat is burned, which translates to weight loss. 

Fat burners do three things to help you lose weight:

  • Increase your metabolic rate
  • Significantly improve the oxidation of fats
  • Prevent the body from accumulating fats

Normally, the human body maintains a homeostatic (or core) temperature through a process known as basal metabolic rate or BMR. It is also known as resting energy expenditure or REE, because it is the energy consumption of the body that maintains normal functions, such as breathing and your heart pumping blood.

The BMR or REE fluctuates a bit but within a relatively narrow range between being asleep and being awake. Physical exercise can increase the efficiency of your heart rate and metabolism but at a limited time period, usually several minutes to a few hours after the exercise depending on the intensity. Then you go back to your normal BMR.

While thermogenic products are sold as food supplements, you should always consult your doctor to ask if they’re safe for you to take. If you have a chronic condition or ailment, you shouldn’t take thermogenic fat burners without first consulting your GP. Even if you don’t have an illness, it’s still better to get professional medical advice before taking any supplements.

As the name suggests, thermogenic fat burners are meant to increase metabolism so your body can burn fats faster by using it as an energy source.

Natural thermogenic biochemicals are enzymes. All enzymatic reactions are thermogenic in nature, which maintains the basal metabolism rate. Introducing supplements that boost the enzymatic actions against fats, or the use of energy in general, can help in weight loss. 

However, there are some risks involved. While the safety of these food supplements has significantly improved over the years, it never hurts to take extra precautions.

Metabolism level scale with arrow
Thermogenic fat burners work by increasing your metabolic rate

Do Thermogenic Fat Burners Work?

Companies that manufacture thermogenic fat burners tend to exaggerate their claims. The two important issues here are safety and efficacy.

Scientific studies suggest that these supplements are safe, but not significantly effective in terms of weight loss without proper exercise and discipline in diet. While these supplements can help increase your metabolism, they should be combined with a lower calorie diet for full effectiveness.

A 2017 study published in the Journal of Sports Science and Medicine on the influence of a thermogenic dietary supplement suggests that thermogenic supplementation is safe. However, it’s worth bearing in mind that the fat mass of the volunteers who took the supplement wasn’t significantly reduced compared to those who took the placebo.

An earlier study, however, published in the International Scholarly Research Journal, indicated that, based on the available evidence, commercially available dietary supplements seem to contribute to the significant increase of the resting energy expenditure (REE). 

The study wasn’t conclusive on whether that was mainly due to the supplements or food consumption. Increase in metabolic rate after eating food or food supplements is normal, but may not significantly contribute to weight loss since it can simply be cancelled out by calories in the food. 

What’s the Difference Between a Thermogenic and a Normal Fat Burner?

Thermogenic fat burners aren’t radically different from other types of fat burners, because many or most of the ingredients are the same. However, instead of focusing on lipolysis (the breakdown of fats through enzymes and water) like ‘normal’ fat burners do, thermogenic fat burners focus on the rate of metabolism and energy consumption.

For example, caffeine is one of the most common ingredients in thermogenic fat burners. It increases the heart rate and blood circulation, making the body consume more energy. Fats and other sources of calories are oxidised in the process.

Coffee bean heart rate concept
Caffeine is a common ingredient in thermogenic fat burners because it increases the heart rate

The Science Behind Thermogenic Fat Burners

The science behind thermogenic fat burners is still inconclusive in terms of significant correlation with weight loss.

Supplements don’t seem to have a great impact on weight loss if you just rely on them alone. For best results, weight loss supplements must be combined with a balanced, healthy diet and regular workouts.

In terms of scientific basis, the way thermogenic fat burners work boils down to cellular respiration. The various ingredients in fat burners help boost your body’ energy expenditure. Cellular respiration is divided into four stages, wherein food is broken down and spent as energy:

  • Step 1 – Glycolysis: The glucose from food or broken down fats is converted into two molecules of pyruvates
  • Step 2 – Pyruvate decarboxylation: Pyruvate molecules are oxidised into Acetyl-CoA and carbon dioxide
  • Step 3 – Citric acid cycle or Krebs cycle: Acetyl-CoA participates in the cycle that occurs in the mitochondria. ATP is produced and spent
  • Step 4 – Oxidative phosphorylation: This establishes the proton gradient in the mitochondria

Aside from caffeine, other common ingredients in thermogenic fat burner food supplements include:

  • Capsicum: This is naturally found in chilli. It activates the brown adipose tissue, thereby increasing the energy expenditure of the body
  • Green tea: The polyphenols in this helps increase the liver’s ability to process fat
  • Vitamin B6: This vitamin has an important role in metabolism, helping in the conversion of food into energy
  • L-tyrosine: This amino acid is essential in creating the neurotransmitters adrenaline and noradrenaline. It’s also used by the body in making thyroid hormones t3 and t4. These are all important in controlling the rate of metabolism
  • L-carnitine: This helps the body turn fat into energy
  • Sinetrol: This is derived from the peel of citrus fruits. Similar to green tea, it’s rich in polyphenols that aid the liver in digesting fats


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