top of page

Should You ACTUALLY Break Your Fast With A Protein Shake? [Fasting Do's and Don'ts]

Updated: Jan 19, 2022

Should you really break your fast with a protein shake? Or can you have a protein shake while fasting? Today, I'm breaking down the science-backed details of protein shakes, Intermittent Fasting and the best type of protein shake to achieve your weight loss goals with fasting!

protein shake after fasting

But First, Do Protein Shakes Break Your Fast?

Protein shakes at the very least will consist of a protein powder and a liquid base, such as almond milk, dairy or water. One of the main goals with Intermittent Fasting is to not spike insulin, the fat storing hormone, so that the body can naturally turn on fat burning mechanisms and work toward a weight loss goal.(1) With this in mind, anything that will spike insulin will then break your fast. Protein and carbohydrates are the main macronutrients that will spike the storing hormone insulin (although protein to a much lesser degree than carbohydrates). Therefore protein shakes will break a fast.

There are other forms of fasting that only allow for water, unsweetened coffee or tea during your fasted state. However, if your main objective with Intermittent Fasting is weight loss, then you can opt for either the water fast or use non-insulin spiking drinks such as Keto Coffee during your fast.

Pssst - wondering what type of fasting is best for your goals? Click below for my free Intermittent Fasting Schedule quiz to find out!

protein shake after fasting

Should You Have A Protein Shake After Fasting?

Protein is one of the most important nutrients to consume after your Intermittent Fast because it significantly boosts satiety, prevents hunger and helps improve body composition and weight loss progress.(2)

However, another very important macronutrient when breaking an Intermittent Fast is fat. High quality fats trigger the body to release the satiety hormone cholecystokinin, or CCK. This can help to significantly reduce hunger and prevent sugar cravings.(3)

A final necessary component is fiber. Fiber acts on the stretch mechanisms in the stomach and lets the brain know that it's full. These three components of protein, fat and fiber are crucial for boosting satiety, preventing hunger and reducing sugar cravings for long term weight loss success.

A standard protein shake with just protein powder is missing out on the other two important ingredients of fat and fiber. So protein powder mixed with water on its own isn't sufficient to break a fast with. However, when combined with fat and fiber sources, protein powder can certainly be used when breaking a fast.

protein shake after fasting

Best Intermittent Fasting Protein Shake After A Morning Workout

Instead of opting for a protein shake, transforming your protein powder into a highly satiating smoothie that contains protein, fat and fiber is an excellent way to break a fast while working toward a weight loss goal. Plus, the protein in your smoothie will contribute to the amino acids necessary to help repair your muscles after a morning workout.

Easy fiber sources include chia seeds and flax seeds. Fat can also be added in the form of almond butter, peanut butter, coconut flakes and various nuts or seeds. It's important to strike a balance between high quality proteins, fats and fibers when formulating your break-fast smoothie.

You can checkout one of my go-to, break-fast smoothie recipes combining each of these necessary components with the video below!

Jump start your goals with the Complete Intermittent Fasting Program! Get 7 weeks of meal-by-meal planning and the step-by-step details on how to achieve your weight loss and wellness goals!

protein shake after fasting

Head over HERE to get started!

Your Nutritionist,


protein shake after fasting

Autumn Elle Nutrition

93,624 views2 comments


I understand the logic behind adding fats and fiber to reduce hunger and prevent cravings. However, the downside is that you're adding more calorie's to your shake. I like to keep liquid calorie's as low as possible, so I can have bigger meals in my eating window. If you want to prevent hunger / cravings, then take a weight loss probiotic. Seriously, intermittent fasting combined with a good quality probiotic is a weight loss hack. You can find a very good one here You can still get your fats & fiber with your meals, and you'll have more calories to enjoy. Win/win

Replying to

Hi Kacey! It's fairly common to not feel super hungry after a fast. This is often due to metabolic flexibility and the body getting fuel from internal fat stores. However, to ensure adequate protein and nutrients are eaten within the eating window, I personally don't advise extending the fast longer.

bottom of page