Can you take protein shakes while intermittent fasting

Can You Take Protein Shakes While Intermittent Fasting?

Andrew Brewer - Intermittent Fasting Expert

Written by Andrew Brewer. Updated on January 2023.

Medically reviewed and fact checked by our team.

Can you take protein shakes while intermittent fasting

When it comes to breaking fast, it’s not always about what you eat. It’s also about what you drink. As a general rule, if your drink has calories – whether it’s protein, sugar, or something else – you’re breaking your fast. 

Intermittent fasting is two-fold. You don’t want to eat any calories during this period, but you also don’t want to trigger a metabolic response from any supplements you’re taking. Protein shakes do both, so they’ll break your fast. But that doesn’t mean you should skip them all together! Instead, save the protein shakes for your eating windows. You can still reap the fantastic benefits of this nutritious drink as your body works through its caloric stores during fasting. 

Importance of Protein in Your Diet 

The quality of what you eat is just as important as when you eat, so it’s a great first step that you’re looking to drink protein shakes while you’re fasting. Unfortunately, if you do, you’ll break your fast. They have calories and will trigger a metabolic and insulin response in your body. The only things you can really drink without breaking your fast is water, tea, and black coffee – without the sugar of course! 

Instead, integrate protein shakes during your eating windows. Protein is critical in helping you feel full longer. It also helps boost your metabolism during fasting. It’s a win-win, so first start by identifying how much protein you need every day. Once you’ve got that number in mind, create a meal plan of how you can hit it. If you struggle to get enough protein through food, protein shakes are going to be critical for you. 

Look at the nutritional label. Some shakes contain additional nutrients like vitamins, minerals, and fiber, so you’ll get a well rounded meal in a single shake. Flavorings can help them go down smoother, just make sure that it doesn’t add too much sugar.  

Should You Break Your Fast with a Protein Shake?

If you’ve just started intermittent fasting, after you fasting window is up, you’ll be starving, looking to break your fast with the nearest thing available. For those who have been intermittent fasting longer, they know you have to ease into eating. Your body needs time to acclimate to processing food, so you want to be strategic in what you eat or drink to not shock your body and put it into a food coma right out of the gate. 

Drinking a protein shake, as long as it has fiber, can be a great way to break your fast. It contains a lot of the nutrients your body will be craving. However, they often don’t include fat, so you’ll want to follow it up with some nuts or healthy fat-rich foods to kickstart your body. It’s a gentle way to break your fast, so while the juicy burger may be calling your name, resist the urge. You’ll thank yourself later when you’re not feeling sick.

Remember, what you eat is just as important as when you’re eating during an intermittent fast, so during your eating windows focus on fiber, healthy fats, and protein. Protein shakes are an easy way to get a concentrated dose of protein in your body, just make sure the monitor the sugar content. You don’t want to undo your work by ingesting too much sugar in your food and drink. 

So Do Protein Shakes Break Your Fast?

Yes, protein shakes will break your fast. You cannot eat or drink anything that has calories during a fasting window. Often, many people forget that you can drink your calories too, so pay close attention what you drink. During fasting windows only drink water, tea, and black coffee without any added sweeteners. Even if they are calorie free, your body can still have an insulin response which will break your fast.

Andrew Brewer

Andrew Brewer

Andrew Brewer started to give people the guidance that he never received when he was first starting. His goal is to make your goals achievable and to offer you only the best fasting apps that the internet has to offer. You're not on your own - Andrew and the entire family of reviewers at are here with you every step of the way!