One of the most popular supplements on the market are fat burners.
Suggested to help melt fat and get you lean for summer, they are often marketed as a great way to take your physique to the next level -- but do they actually work, or are they a piece of fiction?
Fat Burning Supplements
There are a number of different compounds that can have an impact on your capacity to lose fat. Although these compounds impact your body via a number of different physiological systems, they tend to elicit fat loss through one or two mechanisms:
- Increasing fat metabolism
- Boosting energy expenditure
Fat metabolism simply describes the process by which your body breaks down and uses fat for energy.
In short, compounds that increase fat metabolism facilitate this process. They can do this by making your fat more available for energy production, or by increasing the speed at which your body breaks down fat for energy.
No matter what approach they take, these compounds ensure that more of the energy you burn everyday comes from fat.
Then we have energy expenditure.
Your body has a set metabolic rate, which describes the amount of energy your body expends to maintain its normal physiological processes each and every day. You can think of this as the energy required to stay alive.
Compounds that boost energy expenditure act to increase your metabolic rate. This increases how much energy you burn every day irrespective of your exercise levels.
This makes creating a daily energy deficit easier.
Do Fat Burners Really Work?
When it comes to fat burners, we have some very clear mechanisms as to why they might help you lose fat -- however, they won't do it all for you.
To lose fat, you still need to be in a sustained energy deficit.
Looking at it in a simple manner, an energy deficit is a state where you consume less energy than you expend on a daily basis.
For example, if your daily energy requirements to maintain weight are 1800 calories per day and you only consume 1500 calories, you are in an energy deficit of 300 calories per day. Given that you still need to burn this same 1800 calories to survive, the 300 comes from your fat stores.
Over time, this leads to fat loss.
With all that in mind, if you are not eating in an energy deficit, you will not lose weight -- no matter how many fat burners you take.
However, fat burners can make getting into an energy deficit more manageable, while also ensuring that more of the energy you burn comes from fat and not stored carbohydrates -- ultimately making the fat loss process easier.
Best Fat Burning Supplements
We now know that fat burners could have a place in your supplement regime -- but not all supplements are created equal.
As a result, you want to make sure that your fat burner has some of these scientifically supported ingredients in their profile to ensure they are actually effective,
Gamma-Butyrobetaine, or GBB for short, is a naturally occurring compound that your body uses to synthesise L-Carnitine -- which is an important amino acid that plays a role in the fat metabolism process.
More specifically, it is a primary player in a process known as beta oxidation -- which essentially describes the way your body breaks down fat for energy in the presence of oxygen.
This means that the supplementation of GBB can increase fat metabolism, making sure your body burns more fat for energy. There is also some evidence to suggest that taking it before exercise can increase the amount of fat you burn during that bout of exercise  -- making it a great option to take before some cardio.
Rauwolscine is a naturally occurring dirritvie of “yohimbe” -- a compound that comes from the yohimbe plant, and is said to increase energy levels and improve feelings of happiness and emotional wellbeing,
More importantly, rauwolscine blocks “alpha-2 adrenergic receptors” in a much more effective way than Yohimbe, making it a very potent fat loss supplement .
See, alpha-2 receptors are found throughout your brain and your body. When they are activated, they actually act to calm the body, lowering heart rate, increasing insulin secretion, and enhancing energy storage.
But by blocking these receptors, rauwolscine reduces fat storage and increases fat metabolism. Moreover, it also promotes the release of norepinephrine and epinephrine, which increases heart rate and energy expenditure.
This makes it a great fat burning option that hits both of the primary mechanisms mentioned above.
Theobromine is a natural compound found in both cacao plants and tea leaves, that has been shown to exhibit similar effects on the body as caffeine.
In this manner, it increases blood flow throughout the body, while also promoting the secretion of key hormones epinephrine and norepinephrine. These two hormones are known to increase both heart rate and metabolic rate .
As a result, the supplementation of theobromine can lead to an increase in energy expenditure, making achieving an energy deficit easier.
Acetyl L Carnitine
AS discussed in detail when talking about GBB, L-Carnitine is an amino acid that plays a role in the process of beta oxidation -- which is again, the process by which your body breaks down fat for energy.
This means that supplementing with L-Carnitine can contribute to a larger portion of the energy you burn coming from fat .
Something that is worth noting here is that your body has the ability to store up GBB and L-Carnitine. As a result, supplementing them together ensures that you have adequate amounts available to facilitate fat metabolism at all times.
Tyrosine is another unique amino acid found in your body.
However, this amino acid is particularly important because it helps your body make a number of very important substances, dopamine, adrenaline and noradrenaline, and your thyroid hormones -- all of which impact upon your metabolism.
Like many of the other compounds listed in this article, the impact it has on dopamine, adrenaline, and norepinephrine, causes a marked increase in energy expenditure.
But more important is its impact on your thyroid hormones.
Research shows that it can increase “T3” (the most active thyroid hormone) while simultaneously lowering another hormone called “TSH”, which can often be linked to hypothyroidism .
This suggests that L-tyrosine can help regulate your metabolism, which may make it easier to lose fat.
Synephrine is a biogenic amine that is found in high concentrations in the peels of citrus plants.
Evidence has shown that synephrine extract can impact upon the function of your liver, enhancing the production and secretion of numerous enzymes that play roles in energy production.
Within this, it has also been shown to increase heart rate and energy output.
Collectively this has been shown to increase daily energy expenditure while simultaneously boosting your metabolism -- making it one of the most effective fat loss compounds on the market .
In short, caffeine is a compound found in plants that acts as a stimulant. After consumption, caffeine makes its way into your brain and attaches itself to your “adenosine receptors”.
Adenosine is a neurotransmitter that acts to relax the brain, making you feel tired. Under normal circumstances, adenosine levels accumulate throughout the day, facilitating your transition into sleep.
But by blocking these receptors, caffeine actually increases sensations of alertness.
Moreover, caffeine also increases the levels of adrenaline, dopamine, and norepinephrine in your brain. This further increases your energy output, while also helping mobilise your fat stores for energy.
Which ultimately makes it easier to lose fat by facialting your energy deficit .
While fat burners won't do it all for you, they can make your fat loss journey easier by increasing fat metabolism and enhancing energy expenditure -- making them a viable tool in your fat-loss toolbox.
One thing that we will note is that many fat burning supplements also act as stimulants.
As a result, you should always seek advice from a medical professional before commencing supplementation (you know, just to be safe).
- Prasertsri, Piyapong, et al. "Cashew apple juice supplementation enhanced fat utilization during high-intensity exercise in trained and untrained men." Journal of the International Society of Sports Nutrition 10.1 (2013): 1-6.
- Perry, Bruce D., and David C. U'Prichard. "[3H] Rauwolscine (?-yohimbine): a specific antagonist radioligand for brain ?2-adrenergic receptors." European journal of pharmacology 76.4 (1981): 461-464.
- Baggott, Matthew J., et al. "Psychopharmacology of theobromine in healthy volunteers." Psychopharmacology 228.1 (2013): 109-118.
- Huang, Amy, and Kevin Owen. "Role of supplementary L-carnitine in exercise and exercise recovery." Acute Topics in Sport Nutrition. Vol. 59. Karger Publishers, 2012. 135-142.
- Haaz, S., et al. "Citrus aurantium and synephrine alkaloids in the treatment of overweight and obesity: an update." Obesity reviews 7.1 (2006): 79-88.
- Ferreira, G. A., et al. "Does caffeine ingestion before a short-term sprint interval training promote body fat loss?." Brazilian Journal of Medical and Biological Research 52.12 (2019).