Can You Drink Protein Shakes While Intermittent Fasting?

Can You Drink Protein Shakes While Intermittent Fasting?

Intermittent fasting, also known as IF, limits the hours of the day during which you are allowed to eat or drink. IF does not necessarily restrict calories, which is why some find this way of dieting favorable. Additionally, some people find it very easy to fit into their daily routine. Meeting protein goals can be challenging when intermittent fasting. While adding a protein shake can be a quick way to help meet your goals, can you consume protein drinks while intermittent fasting? 

You cannot drink protein shakes when in your fasting window. This is because the protein shake calories and ingredients will cause a spike in insulin, kicking your body out of a fasting state. However, having a protein shake in your eating window can be extremely beneficial. Protein needs will vary based on your weight and can be easily calculated.

In this article, we’ll discuss the benefits of intermittent fasting, best protein shakes while intermittent fasting, as well as how to get enough protein while intermittent fasting. Let’s get started!

Intermittent Fasting Quick Overview

16:8 Rule

The 16:8 rule refers to the fasting cycle. Someone who is intermittent fasting on this cycle will fast 16 hours a day and consume their calories during the additional 8 hours.

For example, a 16 hour fast could be from 7PM-11AM the next day. The 8-hour window where you would consume your calories for the day would be from 11AM-7PM that day.

Benefits of Intermittent Fasting

  1. Intermittent fasting is thought to help with weight loss, in conjunction with or without restricting calories, glucose tolerance, and the gut microbiome.
  2. One study showed a decrease in weight by 3.3kg over a 12-week study period and an improvement in LDL and blood pressure.
  3. Some self-reported benefits include increased energy, improved sleep and decreased bloating.
  4. For some, intermittent fasting fits right into their daily schedule and its easy for them to practice this around their work and daily schedule.

Should You Have a Protein Shake After Intermittent Fasting?

If a protein shake is something you want to break your fast with, that’s great! Having a protein shake can help meet your daily protein goals while you’re in a restricted window of eating.

Best Shakes for Intermittent Fasting

Not all ready-to-drink protein shakes are created equally and reading the nutrition facts label is super important. Let’s take a look at two pre-made protein shakes, and one you can make in your blender with fruit at home!

1. OWYN Pro Elite Protein Shakes

Image Credit: Target

OWYN Pro Elite Protein Shakes have one of the highest protein contents in a ready to drink shake, at 35 grams of protein per bottle. There are zero grams of sugar and added sugar, as added sugar is something you want to avoid when looking for a protein shake.

Additionally, it’s vegan, made from pea protein blend, and gluten free! 

Ingredients (Chocolate Flavor): Water, OWYN protein blend (pea protein, organic pumpkin seed protein, flaxseed oil) gellan gum/acacia gum blend, vegetable fiber cocoa powder, sunflower oil, sunflower lecithin, guar gum, monk fruit extract, Himalayan pink sea salt, natural chocolate flavor, black cocoa greens blend (spinach, kale, broccoli)

Nutrition Facts: 

  • Calories: 230
  • Fat: 7g
  • Saturated fat: 1g
  • Sodium: 350mg
  • Total carbohydrates: 7g
    • Dietary Fiber: 7g
    • Total Sugars: 0g
    • Includes 0g added sugar
  • Protein: 35g

2. Fairlife Core Power High Protein Shake

Image Credit: Amazon

With excellent reviews when it comes to taste, the Fairlife Core Power High Protein Shake packs in 26 grams of protein per 14 oz serving.

It is milk based, but it is suitable for lactose intolerance. There are 5 grams of sugar, from the milk sugar lactose, but there is no added sugar in this product.

Ingredients: Filtered Lowfat Grade A Milk, Alkalized Cocoa Powder, Contains Less Than 1% of:  Natural Flavors, Monk Fruit Juice Concentrate, Stevia Leaf Extract, Carrageenan, Cellulose Gel, Cellulose Gum, Maltodextrin, Acesulfame Potassium, Sucralose, Lactase Enzyme, Vitamin A Palmitate, Vitamin D3

Nutrition Facts:

  • Calories: 170
  • Fat: 4.5
  • Saturated fat: 3g
  • Sodium: 260mg
  • Total carbohydrates: 8g
    • Dietary Fiber: 2g
    • Total Sugars: 5g
    • Includes 0g added sugar
  • Protein: 26g

3. Homemade Protein Shake

Let’s face it, it’s healthier and more affordable to make protein shakes at home. So if you have some extra time, give it a try!

The best thing about this is that you know exactly what is going into your protein shake each day.

Homemade shakes might be higher in carbohydrates from the fruit, but that is nothing to be afraid of. Fruit offers so many nutritional benefits such as fiber, vitamins and minerals and is a necessary part of a healthy diet!


  • ½ cup frozen cherries
  • ½ cup frozen mango
  • ½ cup frozen cauliflower rice (Promise you can’t even taste it!)
  • 1 scoop protein powder (I currently have Ascent Native Fuel Whey Protein, Vanilla on hand)
  • 1-2 tsp cacao nibs (Optional, for texture if interested!)
  • Enough milk to blend, about 1/3-1/2 cup (Non-fat milk, unsweetened almond milk, preferred)

Nutrition Facts:

Approximate calories and protein per shake: 225-250 calories, 25-30 grams of protein (based on type and amount of milk used)

How to Get Enough Protein While Intermittent Fasting

When following a weight loss program, you want to make sure you are losing fat mass rather than lean body mass. Protein is important as it helps maintain your lean body mass, preserving your muscles.

If you’re concerned about meeting your protein needs while IF, planning your meals and snacks for you 8 hour window can be a sure-fire way to know you are meeting your needs.

High protein foods include Greek yogurt, eggs, milk, fish, chicken, turkey, tofu, and peas.

Adding a protein shake with 20+ grams of protein will also assure you meet your needs daily if it is difficult to plan your meals.

How Much Protein Does My Body Need?

The average adult needs at least 0.8-1.0 grams per kilogram of body weight for protein. If trying to build muscle, more protein can be needed.

If you have medical conditions, your protein needs can vary. Consult your Registered Dietitian for an individualized plan.

Let’s take Mr. A, as an example. Mr. A is 220 pounds.

  1. To convert pounds to kilograms, divide your body weight by 2.2. In this case, 220 pounds / 2.2 = 100 kilograms (kg)
  2. Multiply your weight in kilograms by 0.8-1.2 to find your range of protein needs.
  • 100kg x 0.8 = 80 grams of protein
  • 100kg x 1.0 =  100 grams of protein
  • 100kg x 1.2 = 120 grams of protein

What Can I Drink During Intermittent Fasting?

You can drink water, black coffee, unsweetened tea and other zero calorie beverages during intermittent fasting. Anything that contains calories/sugar will break your fast.

Is Intermittent Fasting Suitable for Everyone?

IF is not suitable for everyone. It is recommended to not follow intermittent fasting if you are under 18 years old or pregnant/breastfeeding.

Those with a history of an eating disorder or disordered eating should not follow IF. Becoming obsessive with timing of eating can be mentally harming and overall place more stress on the body. IF should not be used as an “excuse” to skip meals.

Those who have certain medical conditions such as Type 1 or Type 2 diabetes should talk to their doctor or dietitian before considering IF.

Additionally, most studies on IF are done predominantly in men. More research is needed for IF in women as women have different hormone cycles than men and it could potentially have a negative impact on women’s’ hormones.

Focusing on the quality of the diet rather than the timing and quantity can be more beneficial in the long run for some rather than IF.

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Choosing Nutrition Team

Here at Choosing Nutrition, our goal is to help people with making smarter food choices. Whether you're wondering about vegan, keto, paleo, or other diets, we'll help you determine which options fit your nutritional lifestyle. Our staff is composed of registered dieticians, nutritionists, and health-conscious individuals.

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