Combining protein shakes with intermittent fasting can seriously ramp up your fitness gains. However, it’s important to time your protein intake correctly.

Intermittent fasting can boost growth hormones and help preserve your muscle mass during your fitness and weight loss journey.

Let’s dive in and find out how you can sip on those delicious protein shakes and still keep the fasting benefits intact.

Key Takeaways:

  • You can take low carb high protein shakes close to your eating window or even better during your eating window.
  • Protein shakes clubbed with Intermittent Fasting can accelerate weight loss.
  • To determine the best time to drink protein shakes while fasting, check what your eating window is. It may differ on the type of IF you’re following, 16/8 being the most popular one.
  • During your eating window, make sure you’re not consuming a lot of calories. Consume a nutrient-dense balanced diet instead.

What is Intermittent Fasting?

What is Intermittent Fasting? What is Intermittent Fasting?

Intermittent fasting (IF) is more than just a diet. It is an eating pattern that alternates between periods of fasting and eating. These fasting periods can range from 12 to 24 hours. The eating window is usually 2 to 8 hours depending on personal preferences.

The most popular and practical IF method is the 16/8 in which you fast for 16 hours and enjoy an 8-hour eating window. There are no restrictions on what you can eat. No food groups are eliminated. The weight loss occurs since the eating time limits naturally create some amounts of calorie restriction.

You can optimize your body's metabolic processes and promote various health benefits by increasing the fasting window. This triggers autophagy, a cellular recycling process that breaks down and reuses or removes damaged cell components, thus promoting your overall health and well-being.

Does Consuming a Protein Shake Break a Fast?

Does Consuming a Protein Shake Break a Fast? Does Consuming a Protein Shake Break a Fast?

What breaks fast? Well, this depends on your definition of fasting. Technically, fasting means abstaining from all food and drink. So even a glass of water or coffee can break a fast.

Now, does a protein shake break fast? That depends on your goal of fasting! If you are fasting for fitness benefits - weight loss, toning, and muscle building, it’s wiser to incorporate protein shakes into your eating plan.

For promoting muscle protein synthesis, it’s best to have your protein intake within an hour or two post your workout. To boost your workout performance, you can have a pre-workout protein shake.

You can consider having low-carb, low-calorie protein shakes during your fast, preferably closer to your eating window. Even better, if you can time them during your eating window. So make sure to plan your workout times accordingly.

If your IF goal is for its autophagy or other metabolic health benefits, it's best to extend the fasting window as much as possible and have the protein shakes only during your set eating window.

When to Drink Protein Shakes during the Eating Window?

Now, let’s focus on having protein during the eating window. What’s the best time to have an intermittent fasting protein shake? In the 16/8 IF, you get an 8-hour eating window. This leaves you plenty of time to choose a workout slot - before, after, or during your eating window.

If you work out before the eating window, then have your post-workout protein shake at the beginning of your eating window. Your body is primed, hungry, and ready for all the amino acids and nutrients in your protein drink.

If you prefer to work out after the eating window, then have your protein shake as a pre-workout towards the end of your eating window. Don’t work out immediately after heavy meals or drinks. Allow an hour or so for the digestion to settle down. Now you are fueled and ready to rock that workout!

You can have protein shakes on rest days too as long as you stay within the eating time slot.

Does it Help when Losing Weight?

Including protein shakes in your intermittent fasting plan supports your weight loss goals. The combo of IF and protein shakes is like rocket fuel for your weight loss journey.

IF helps create caloric restriction while protein enhances satiety, making you feel full for longer. Considering the thermic effect of protein, your body has to spend more energy to digest it, and this translates to increased calorie burning.

While IF does promote weight loss, eating too many calories during your eating window can result in weight gain instead of weight loss. That goes for the protein shakes too - too many calories in your protein shake can also lead to weight gain.

What Other Protein Foods to Eat While Fasting?

During intermittent fasting, make sure to choose nutrient-dense foods for your eating window. For optimum health, have balanced meals with plenty of quality protein sources, healthy fats, complex carbs, vegetables, fruits, nuts, and seeds. This will provide you with all the nutrients your body needs. Focus on whole foods and minimize processed ones.

You can include a variety of protein sources such as eggs, chicken, meat, fish, cottage cheese, tofu, legumes, etc. Protein shakes are a convenient and easy way to bridge nutritional gaps and meet your recommended daily protein intake. You can have them for breakfast, lunch or even dinner, depending on your eating windows. You can also include some protein snacks such as nuts, boiled eggs, peanut butter, hummus, and yogurt to ramp up your protein intake.

3 Protein Drink Options when Fasting

3 Protein Drink Options when Fasting 3 Protein Drink Options when Fasting

Here are intermittent fasting protein shakes you can enjoy during your eating window. These protein-packed treats also contain healthy fats. Ingredients such as spinach and seeds offer fiber, vitamins, and minerals. Adding coconut water gives you electrolytes. You can also add some coffee to your protein drink to make a preworkout shake that boosts your energy and workout performance.

1. Classic Whey Protein Shake


  • 1 cup of almond or coconut milk
  • 1 tablespoon peanut butter
  • 1 scoop of whey protein powder

Method: Blend all ingredients until smooth. Use cold milk or ice cubes if you prefer your drink chilled.

2. Vegan Green Protein Smoothie


  • 1 scoop plant-based protein powder
  • 1 cup coconut water
  • 1 cup spinach
  • 1/2 banana

Method: Blend all ingredients for a refreshing, nutrient-rich vegan protein shake.

3. Chia-Coffee Protein Pudding


  • 1 scoop protein powder
  • 1-2 tsp of coffee powder
  • 1 cup unsweetened almond milk
  • 2 tablespoons chia seeds

Method: Blend all ingredients till smooth. Refrigerate overnight for a satisfying, pudding-like protein treat. You can use a good quality protein coffee powder. You can add some cocoa powder to create a mocha flavor. Serve topped with nuts, berries, and banana slices.



Including protein shakes in your intermittent fasting journey will help you meet your health and fitness goals. However, this needs to be aligned with your eating window to ensure you reap all the health benefits of intermittent fasting.

Individual responses can vary. So you should listen to your body and tailor your fasting approach accordingly. If you have any medical issues, always consult your healthcare provider before changing your diet and workout routines.


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