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Taking Fat Burners On An Empty Stomach

Taking Fat Burners On An Empty Stomach: Should You Do It?

Fat burners are a supplement that can help people to lose fat. In the last couple of decades, they’ve become popular with bodybuilders, athletes, and gym goers looking to get shredded.

Although they aren’t a magic pill that can deliver sudden fat loss, fat burners can help people to maximize their fat loss results over time.

But, as with any supplement, to see the best results it’s important to get the timing right. 

We’re often asked about taking fat burners on an empty stomach and whether or not you should do it and as I’ll go on to explain, there are both potential benefits and downsides to doing this.

How Do Fat Burners Work?

Before explaining whether or not you should take fat burners on an empty stomach, it’s important to understand how fat burners work.

In general, fat burners work by speeding up people’s metabolisms. Your metabolism is essentially how many calories your body burns throughout the day. So by speeding up your metabolism, you should burn more calories.

This is usually done through high doses of stimulants, such as caffeine, as stimulants have been shown to speed up people’s metabolisms. 

Depending on their ingredients, they can also burn calories by raising people’s body temperatures. As your body temperature increases, your body works to cool it down, which burns calories. 

This process is referred to as ‘thermogenesis’.

As well as increasing the number of calories people burn, they can also lead to fewer calories being consumed by suppressing people’s appetites.

Should You Be Taking Fat Burners On An Empty Stomach

Taking a fat burner on an empty stomach may help with faster absorption, potentially making them more effective. Taking them before eating can also help to support appetite control. However, taking them without food may cause side effects such as digestive issues.

If you’re unsure whether or not to take fat burners on an empty stomach, you should check the product label. 

It may say on the instructions for your fat burner how to take them. If it’s recommended that you take them with food then you should follow the instructions given as these instructions are there for safety.

If the product you’re using can be taken on an empty stomach, or with food, then there are some benefits and drawbacks to consider.

Benefits Of Taking Fat Burners On An Empty Stomach

Taking a fat burner on an empty stomach may be able to deliver some benefits.

Firstly, as I explained in the last section, a key way in which fat burners work is by speeding up people’s metabolisms which leads to more calories being burned. 

Although people’s metabolic rates vary, in general people’s metabolisms are slowest first thing in the morning when they have just woken up.

Taking a fat burner at this time, before eating breakfast or doing anything else, means that it can kick start your metabolism for the day. This gives it more time to work throughout the day.

Secondly, as fat burners can help to suppress appetites, taking it on an empty stomach before you’ve eaten anything can help to control hunger levels and may lead to fewer calories being consumed.

Thirdly, taking a fat burner on an empty stomach may help with faster absorption. This is because when people eat food, their body starts to break it down and absorb it. 

If you take a supplement after a meal, then it can take longer for your body to break it down and absorb it as the stomach is already full and that food needs to be processed first.

Related – How long do fat burners last in your system

So, taking a fat burner on an empty stomach may help with faster absorption potentially leading to better results over the course of a day! 

Downsides Of Taking Fat Burners On An Empty Stomach

Whilst there are potential benefits associated with taking a fat burner on an empty stomach, including faster absorption and appetite control, there are also potential downsides. 

Probably the main downside of taking fat burners on an empty stomach is the risk of side effects.

The side effects associated with fat burners vary. They depend on what ingredients they contain, the dose of those ingredients, and people’s individual responses to them.

That being said though, common side effects include gastrointestinal symptoms such as stomach pain, nausea, and diarrhea. They can also cause shaking, increased heart rate, and insomnia. 

These side effects are usually caused by the high levels of stimulants found in fat burners.

Taking fat burners on an empty stomach may increase the risk of these gastrointestinal side effects.

For example, caffeine has been shown to increase the production of stomach acid. Stomach acid is necessary to break down and digest food but when you haven’t eaten higher levels can irritate the stomach lining, causing reflux, nausea, stomach pains, and other side effects.

One possible solution to this is to consider the type of fat burner. 

The main difference between types of fat burners is ‘stimulant fat burners’, which contain stimulants like caffeine, and ‘non-stimulant fat burners’ or ‘stimulant-free’, which don’t contain stimulants.

Related – Stimulant vs non-stimulant fat burners

As many of these gastrointestinal side effects are associated with stimulants, going for a non-stimulant fat burner may help to avoid them. 

With this being said though, it does depend on what ingredients they contain, as non-stimulant fat burners can also contain ingredients that cause gastrointestinal side effects.


Overall, there are potential benefits and potential downsides to taking a fat burner on an empty stomach. 

Potential benefits include faster absorption, an early kick start to your metabolism, and appetite control. 

On the other hand, potential downsides include digestive side effects such as nausea, stomach pain, and reflux.

When it comes to which option is best, it will depend on your individual response. For example, if you have a sensitive stomach then taking them without food may not be a good idea. 

If you need further help on supplementing with fat burners, check out our dedicated article on the best time to take fat burners. This will consider the time of day and ingredients which are other factors to consider alongside an empty or full stomach.