Does creatine break a fast? — Explained by SIMPLE

Written by Melissa Renae

Medically reviewed by Louise Bula, RD

“Intermittent fasting,” “muscle,” “fat loss vs. weight loss,” “body composition,” “endurance,” “performance” — all these terms swirl around as you start your wellness journey, and now another one has been thrown into the mix, “creatine.” 

You’ve been doing your research on intermittent fasting and how it fits into your wellness goals and works for your body. You’ve tried a schedule or two, and things are going well, or maybe not as well as you’d like, and you’re wondering, “Is intermittent fasting not working for me?” Then you heard about creatine supplements, and it sounds pretty cool. It may even help out with your fasting efforts, woohoo! 

Hmmm, but how does it fit in with fasting? You may be asking yourself, “Can I take creatine while fasting?” and honestly … “What even is it anyway?” (Tbh, it kind of sounds like something a superhero would run from.) Or maybe you’re just wondering, “Does creatine break a fast?”

If all of these questions have you feeling confused about fasting, don’t give up on fasting just yet! We can help you out with that, but first, let’s answer your big creatine questions. 

What is creatine?

Creatine is a naturally occurring peptide compound in your body. It is made up of three amino acids — arginine, glycine, and methionine — synthesized first in the kidneys and then in the liver. Its long-studied ability to improve strength and performance has made it a long-time favorite in fitness, performance, and muscle-building circles.[1]

It can be found in foods like red meats, fish, and poultry and in lesser amounts in plant-based foods like oats, quinoa, spinach, and avocado, but it is more commonly consumed as supplements.

How does it work?

The supposed magic of creatine comes from its role in producing the energy needed for short bursts of high-intensity exercise like HIIT workouts or weight lifting. It supports the ATP (adenosine triphosphate) system in the body. The ATP system is the cell’s energy source. Phosphocreatine (i.e., how the majority of creatine is stored in the muscles) helps to quickly replenish ATP during those power moves in the gym or on the track. Creatine supplements increase the phosphocreatine available, so muscles have a ready supply of energy for peak performance. 

So, will creatine break a fast?

Intermittent fasting and working out can already be a complicated dance because fasting can make it a little more difficult to get enough energy to fuel a good workout, especially when it comes to intermittent fasting and bodybuilding. But you’re a pro at this (because you’ve already checked out our resources and taken our SIMPLE quiz), and you’ve got your routine figured out, too. You know how to time your eating and workouts so you feel your best, but now you’re thinking about adding creatine supplements and wonder how it all fits together. You may even already know all about what breaks a fast but still wonder, “Will creatine break a fast?”

Before we answer that question, we want to remind you, as with anything, that we recommend you check back in with your doctor before starting a new supplement. Also, it’s totally OK if you don’t have all that down yet; we’re just manifesting because we know you’ve got this!

Now, let’s get down to the heart of the matter! 

While creatine does help support the energy available for muscle cells to use, it doesn’t contain any calories itself, so creatine, alone, does not break a fast. If you choose to get creatine through food sources or supplements that contain calories, creatine will break your intermittent fasting. 

While some suggest taking creatine supplements with glucose helps increase absorption through insulin’s response to the increase in blood sugar in the body, conflicting evidence, such as this one small study with college-aged men [2], showed that it does not help. At this stage, more research is necessary before drawing any final conclusions. 

How do you take creatine while fasting?

OK, so you’re ready to jump on the creatine supplements train. You’ve got the all clear from your doctor and figured out the best time to take it with your fasting schedule, but you’re still unclear on how to take it. As usual, we got you! 

Take during eating windows: A good way to ensure that your creatine supplement doesn’t break your fast is to take it during your eating window. Take your creatine supplement during those periods when you’re able to consume food. 

Take with non-caloric fluids: If your fasting plan allows for non-caloric beverages during your fasting period (such as water, black coffee, or plain tea), consider taking your creatine supplement with one of these beverages to avoid breaking your fast.

Consider macronutrients: Some forms of creatine supplements might contain negligible calories or macronutrients. It’s a good idea to check the supplement label to confirm what’s included and the amount of calories per serving. If it contains minimal to no calories (<10), taking it during fasting might not significantly impact your fast.

Consult with a healthcare professional: If you have concerns about how creatine supplementation during fasting may affect your specific health condition or fasting regimen, consider consulting with a healthcare professional or a dietitian for personalized advice.

When is the best time to take creatine when intermittent fasting?

Because creatine doesn’t have calories to trigger a rise in insulin levels, you can take it whether you’re in your eating window or fasting window. But remember, that’s only the case if it’s taken with a source that doesn’t include calories, like water or other fasting-friendly beverages. You can learn more about what you can drink while fasting here. 

The best time to take creatine when intermittent fasting is the time that feels best to you and fits your goals. 

Health benefits of taking creatine while intermittent fasting

While the majority of the research surrounding creatine supplementation is on fitness, strength, and performance, there is some emerging research that also suggests some other benefits of taking creatine while fasting. 

• Muscle growth — Intermittent fasting is thought to be a muscle-sparing form of reduced calorie intake. Taking creatine while fasting can support muscle mass maintenance and growth.[1] 

• Cognitive function — Another way that creatine and fasting can work together is in supporting cognitive function.[3] The research on this is still in its infancy (so it’s too early to say anything for certain), but there have been some promising outcomes in improved brain health.[4] 

• Reduced inflammation — So far, it seems like taking creatine while fasting is some sort of a dynamic duo for benefits, and this one is no exception. Intermittent fasting has been shown to have the potential to reduce inflammation, and creatine is here with the assist.[5,6] Again, more research is needed to fully understand any correlations between both fully.

Who could benefit the most from taking creatine while fasting?

While we are big fans of intermittent fasting around here and wish it was the best fit for everyone, we are also realistic and know that everyone has different needs. There are a few groups of people whom we recommend avoiding fasting altogether.

People who

• are pregnant, breastfeeding, or trying to conceive
• are living with type 1 diabetes
• are on prescription medications 
• are under the age of 18 or are 80 years of age or older 
• are extremely active
• have a body mass index (BMI) < 18.5
• have an eating disorder or a history of one (or are at risk of developing one)

Taking creatine while fasting won’t change that, so as you can imagine, our recommended list of those who will benefit from intermittent fasting with creatine looks a little different. 

People who

• have no pre-existing health conditions or are on any medications
• participate in regular weightlifting and cardio training programs
• are focused on wanting to change their body composition by building muscle strength and growth overall

Possible drawbacks of taking creatine while fasting

• Digestive discomfort — If you experience bloating, diarrhea, and/or nausea, you may need to take a smaller dose or try taking it during your eating window.[7] It can also be taken as a pre-workout supplement. 

• Water retention — Creatine can increase fluid uptake into the muscles and cause an increase in weight, especially in a loading phase.[8] While this may benefit the muscle in the long run, it can be a little frustrating if you’re watching the number on the scale. 

Tips on taking creatine during a fast

Alright! Now that we know that creatine, by itself, will not break your fast and that it can support some of the benefits of fasting (talk about a win-win!), let’s review some tips on how to maximize these benefits. 

• Start slow — Intermittent fasting for beginners can be a little tough to get used to, and so can creatine supplementation. Look out for intermittent fasting side effects, and don’t be afraid to change it up if you need to. It’s also OK to hold off on the creatine supplementation until you work out any fasting kinks, then start low and slow. 

• Stay hydrated — Poor hydration is not only an intermittent fasting mistake but an overall mistake for supplementation and trying to achieve any wellness goals. Drink plenty of water for creatine absorption and to prevent stomach discomfort, muscle cramps, or fatigue. 

• Take it consistently — Once you’ve gotten to a happy place with your fasting and creatine regimen, stick to it to see the best results and prevent any possible side effects. 

Written by Melissa Renae

Medically reviewed by Louise Bula, RD