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Fat burners

The term “Fat burners” refers to a category of supplements. These supplements are claimed to influence fat metabolism in some way. Fat burners are generally believed to help people lose fat and they are certainly marketed as a quick and easy solution to weight loss. But do fat burners really help with weight loss? This blog will dive a little deeper into the evidence.

What are fat burners?

Fat burners are usually supplements comprised of a number of different ingredients. Each of these ingredients will have been linked in some way to fat burning and the assumption is that the more of these ingredients you put together in one supplement, the more effective it will be. But what are these ingredients? And are they indeed effective? If so, what are the most effective ingredients? What dose would be required? There are also many other practical questions that need to be answered. However, before we answer any of these questions, we also need to address the question: do fat burners actually help to lose body fat?

What is fat burning?

Most people associate fat burning with losing weight and getting rid of some body fat. But that is not what fat burning is. This is a misconception that is happily abused by marketing campaigns. Fat burning (or fat oxidation) is a process where fat is broken down to carbon dioxide. There are many factors that affect fat oxidation. These factors are listed below:

  • Exercise intensity

  • Exercise duration

  • Carbohydrate (and protein) ingested prior to exercise

  • The dietary composition and the availability of substrates (especially carbohydrate)

  • The environmental conditions

Even if we burn more fat, it does not mean we lose body fat. This will only happen when we are in negative energy balance at the same time. So, just stimulating fat burning on its own is not going to help us lose weight.

Even if we burn more fat, it does not mean we lose body fat. This will only happen when we are in negative energy balance at the same time.

What is the most effective fat burner?

The most effective fat burner is exercise. It is possible to increase fat burning 10 times during exercise (far more effective than any ingredient in a fat burner supplement). However, it doesn’t mean that if you exercise you lose weight. It doesn’t make exercise the most effective weight loss tool, although clearly it increases energy expenditure. In order to lose body fat, you need to be in negative energy balance (and probably also in negative fat balance).

How are (false) claims generated?

So, when supplement manufacturers talk about fat burners, they often talk about an ingredient that has been shown to affect fat oxidation in some way. So, for example, a study may have shown that in a petri dish an ingredient (for example, caffeine) increased one aspect of fat oxidation (for example, increased the activity of an enzyme). Does that mean that this ingredient will help you lose body fat? The answer is of course “NO”. It is possible that there is an effect of the ingredient on fat burning, but the chances are small. Such an observation is certainly not evidence that the ingredient has an effect in living humans, in real life situations and by no means does it mean you will lose weight if you consume this ingredient. Yet these assumptions are often made.

Why are fat burning claims problematic?

There are many reasons why fat burning claims are problematic and misleading:

  • The fat burning ingredient may not be absorbed or may be absorbed very poorly before it reaches the tissue

  • There might be other things happening at the same time that counteract this effect

  • What happens in a petri dish in a lab may be very different (and IS often very different) from what happens in real life

  • The dose used may be so high that it can never be achieved in a living human being

  • The ingredient may stimulate appetite, increasing food intake

  • And many more reasons…

Even IF there is some evidence for a claim that fat oxidation is increased in humans, this still does not mean you lose body fat. It is very clear that the majority of “fat burner” claims are overstated and not supported by evidence.

It is very clear that the majority of "fat burner" claims are overstated and not supported by evidence.

Here are some claims on fat burner supplements (including some outrageous ones):

  • Stimulates metabolism

  • Fat burners are a good addition to your diet

  • Filled with high-quality and effective ingredients

  • Tens of thousands of athletes have successfully used Fat Killer when trying to achieve the physique of their dreams

  • Buy fat burners for radical weight loss

  • Not everyone can lose fat as quickly as those with a healthy metabolism and an active lifestyle. Such individuals need a helping hand, such as fat burners, to lose weight faster, more effectively, and to get over that weight loss plateau

  • The advent of thermogenic fat burners has helped many people overcome the frustration and struggle of losing weight.

  • Highly effective supplement that seems to quickly and effectively target your belly fat, which is often difficult to lose

  • May burn your stored fat

  • May suppress your appetite and may help you deal with cravings between meals

  • May block fat production and suppress weight gain

  • It comprises clinically proven glucomannan that makes you feel fuller between meals

What to look out for

All marketing of fat burners have a few things in common:

  1. Provide an unbelievably simple solution for a complex problem: It is easy, effortless and fast.

  2. More ingredients are better. More ingredients are more effective.

  3. Giving an impression that there is a strong body of science behind the products (while there isn’t).

  4. Products have a number of ingredients that are more “traditional” (i.e that every manufacturer seems to use, and the client therefore expects, for example caffeine, or carnitine). In addition, there are some ingredients to make the product “special” and stand out from the rest.

Although it is impossible to conclude that none of these fat burning ingredients could increase fat oxidation, the chances that these ingredients have physiologically meaningful effects are small. There is far less evidence of any efficacy that is promised in the claims. In a previous blog, for example, we discussed the effects of caffeine. Caffeine is probably the ingredient with the most evidence (and even that evidence is limited). The reality is that even the effects of caffeine are small.


Finally, I would like to say that no fat burner can make the process of losing weight easy. The only way to lose weight through lifestyle is by changing behaviour, by making better food choices, and by being more active. This will need to be done in a sustainable way. Form new habits that will stick. Don’t expect some pills or capsules to do the work for you. The way to weight loss success is to find a way to eat fewer calories, that is sustainable for you, and that you can adhere to.

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6 days ago

This makes playing io games easier


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