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Should You Take Fat Burners on Empty Stomach? Pros & Cons

Isaac Robertson
Published by Isaac Robertson
Fact checked by Donald Christman, BHSc FACT CHECKED
Last updated: March 15, 2023
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Many people get confused by opposing opinions and different instructions for use on fat burner labels.

Most people claim you’ll reach your fat loss goals faster if you take your fat-burning supplement first thing in the morning.

Others believe it’s harmful and advise taking your fat burner after a meal but before workouts with your pre-workouts.

Another recommendation is to spread the total dosage throughout the day regardless of your food intake.

Expectedly, the big question most of my clients ask is when to consume fat burners for the best results.

So, let’s put our in-depth research into practice to find out whether it’s safe and wise to use fat burners on an empty stomach.

Quick Summary

  • You can take fat burners on an empty stomach as it increases the absorption of some thermogenic compounds, making the product more effective.
  • Taking fat burners on an empty stomach also keeps your insulin levels balanced, and controls your appetite.
  • For fat burners to be effective, you should adapt a healthy lifestyle.

6 Reasons to Take Fat Burner on an Empty Stomach

close up view of a man's hand placed on his stomach

Here are a few benefits of taking a fat burner on an empty stomach before breakfast:

  1. Increased absorption of some thermogenic compounds enables them to reach your bloodstream faster, enhancing product effectiveness. That’s because fat-reducing ingredients don’t need to compete for digesting and distributing nutrients with the foods you’ve just eaten.
  2. It provides the necessary metabolism boost in the morning after sleep when your metabolism is naturally slower.
  3. It increases your body temperature and energy level to help you burn more calories, stimulating a faster fat-reducing process.
  4. It helps keep your insulin levels balanced, supporting better appetite control.
  5. It rebalances metabolic hormones like leptin that also work as an appetite suppressant.
  6. Some thermogenic fat-melting compounds may inhibit the enzymes triggered by fasting that allow fat accumulation to prevent further weight gain.

Taking fat-reducing supplements before meals, especially when combined with fasted training, can increase your calorie burn and help retain muscle mass.

A recent study from Northumbria University and certain other studies have proven that fasted exercise in the morning can increase fat oxidation and promote lipolysis (the breakdown of fat stores, especially from adipose tissue), enabling you to burn off up to 20% more body fat [1] [2] [3].

That’s because you get increased blood flow to critical areas containing stubborn visceral fat (midsection, particularly tummy and hips), converting visceral fat into energy during training since glucose from food isn’t available as a form of fuel while fasting.

See the best fat burners for men and the best fat burner brands for women.

The Main Reason Why It Might Not be a Good Idea

woman laying down holding her stomach in pain

The main reason why taking a fat burner before meals might not be a good idea is the increased risk of experiencing side effects.

Mary Sabat, nutritionist and certified trainer, explained that fat burners usually contain some type of stimulant which speeds up metabolism to burn more fat (and also appetite suppressants that help you have lesser cravings for food).

The stimulants might cause unwanted side effects such as  nausea, indigestion or upset stomach, headaches, dizziness, insomnia or increased heart rate— which might be worsened if you were to take a fat burner on an empty stomach.

Some potent compounds may irritate your stomach, causing digestive issues, even intestinal inflammation, and various other health problems.

Besides helping you burn fat and lose weight, green tea extract, caffeine, and other stimulants found in such products typically raise the stress hormone cortisol levels in your system, increasing anxiety.

The effect gets stronger if you drink a lot of coffee, green tea, Guarana, or similar drinks, increasing the daily dose of stimulants you consume.

”Be cautious about using caffeine products to help with weight loss. When used in moderation (400 milligrams or less) by healthy adults, caffeine is generally safe. But too much caffeine might cause nervousness, insomnia, nausea, increased blood pressure, and other problems.”

- Katherine Zeratsky, Registered Dietitian

In addition, while burning calories, your metabolism uses water faster. So, you might be more prone to dehydration if you neglect your water intake.

To avoid making things worse, always check each ingredient on the product label carefully and consult a medical professional before taking any supplements.

Should You Eat Before Taking a Fat Burner?

man contemplating while holding his neck and a bowl of food

Whether you should or shouldn’t eat before taking fat burners depends on various factors.

Those can be ingredients in a particular formula, your health, nutrition, lifestyle, activity, age, recommended doses and directions for use by the manufacturer, and your nutritionist and trainer’s tips.

Related articles:


Is It Ok To Take a Fat Burner While Fasting?

Yes, it is OK to take a fat burner while fasting. They typically don’t break up your fast, plus they may help you preserve lean muscle mass, curb cravings, and enhance endurance if you exercise while intermittent fasting. [4] [5]

Can You Take a Fat Burner and Pre-Workout?

Technically, yes, you can take a fat burner and a pre-workout to get that extra kick of energy for your strenuous training and burn more calories. However, for your safety, make sure you check the ingredients both products contain.

Should I Take a Fat Burner on Non-Workout Days?

You can take high-quality non-stimulant fat burner on non-workout days to help control your blood glucose and insulin levels, curb appetite, cut cravings, and induce thermogenesis (primarily due to thermogenics: compounds like chromium and capsaicin or cayenne pepper extract), even aid post-workout muscle recovery.

BUT, if the pills you’re using are loaded with stimulants, chances are they can do more harm than good when taken on non-training days.

The Verdict - Should You Take Fat Burners Before or After Eating?

No two fat burners contain exactly the same ingredients. So, it’s your personal choice.

My two cents:

Make sure it fits your eating habits.

Never exceed the recommended daily dose hoping for better and faster effects.

Plus, always check all the compounds and seek expert opinion and advice about a specific product you want to supplement your diet and exercise plan to achieve your fat loss and other fitness goals.

Also, don’t forget to share your experience in the comments.


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