Whey Protein Before Bed: Should You Do It?

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Many of my nutrition clients take whey protein to help them meet their daily protein target, but many of them have asked whether whey protein before bed is a good idea or if there is something else they should be taking instead.

So, should you take whey protein before bed? Drinking a protein shake before bed has been shown to promote lean muscle growth and muscle recovery. However, since whey protein digests quickly, it may leave you feeling hungry during the night. For this reason, choosing a slower-digesting protein like casein would be a better option.

However, if you would prefer to stick to a whey protein shake before bed, there are things that you can do to slow down the rate of digestion, making it as effective as casein. I provide a whey protein bedtime snack recipe that does just that in this article.

In addition, I will talk about:

  • Benefits and drawbacks of drinking a protein shake before bed
  • Whey Protein vs casein protein before bed – Which is better?
  • What should you mix with whey protein before bed?

Benefits and Drawbacks of Drinking a Protein Shake Before Bed

While there are benefits to drinking a protein shake in the evening before you go to sleep, there are also potential drawbacks that should be considered.

Benefits of Drinking a Protein Shake Before Bed

Pros vsCons of drinking a protein shake before bed

1. Could Increase Athletic Performance

According to this study, drinking a protein shake before going to bed can potentially improve strength levels in your workouts.

The researchers found that those who drank a protein shake before bed and followed a resistance training program gained more strength than those who were resistance trained and did not have a protein shake before bed.

The type of protein shake used in this study was a casein protein supplement, not a whey protein supplement. Nevertheless, the ingestion of a protein supplement before bed was shown to promote strength gains.

2. Can Encourage Fat Loss

Drinking a protein shake before bed can be a great way to mitigate late-night cravings, which can help you adhere to your diet and promote fat loss. 

However, a protein shake before bed will only be beneficial for fat loss if you are simultaneously in a calorie deficit (eating fewer calories than your body needs to maintain weight).

A protein shake before bed can also encourage fat loss because protein is the most thermogenic macronutrient, meaning it burns the most calories while being digested compared to both carbs and fats. 

Therefore if you are ingesting calories from protein before bed rather than eating them in the forms of carbs or fat, your body is going to burn more calories.

3. Allows You To Build Lean Muscle Mass And Supports Healthy Aging

When paired with a consistent resistance training program, consuming a protein shake in the evening before bed can prevent muscle breakdown and promote muscle building while you sleep.

This study on older men (around 70 years old), demonstrated that when a protein shake was ingested before bed having completed resistance training exercises earlier in the day, there was a higher rate of muscle protein synthesis (muscle building).

Additionally, those who supplemented with protein before bed were able to preserve more lean muscle mass, which is incredibly valuable because muscle loss happens at a higher rate with age.

4. Promotes Faster Recovery From Exercise

There is also evidence to support that taking a protein shake supplement before bed could help to promote better muscle recovery and reduce muscle soreness after resistance training. 

This is helpful if you are taking part in a rigorous exercise program since increased muscle soreness could lead to more time spent recovering between workouts.

Research indicates that individuals who drink a protein shake in the evening before bed can experience improved overnight recovery from their workout compared to individuals who take part in the same workout but do not consume a protein shake.

The theory behind these results is that evening consumption of the protein shake increases muscle protein synthesis (muscle building), which helps to repair muscle damage that occurred during exercise.

It’s unclear whether the timing of the protein shake is the factor that influences muscle recovery overnight or if the evening protein shake simply contributes to your daily protein intake which if sufficient will promote recovery.

5. Helps You Meet Your Daily Protein Target

Whether you are aiming for fat loss or trying to build muscle, a higher protein diet can help you achieve these body composition goals.

Eating enough whole-food protein sources throughout the day is the best way to reach your daily protein goal, but if you have a particularly high daily protein target, it could be difficult to do so without supplementation.

Having a protein shake before bed can help to contribute to your daily protein goal since most protein shakes contain around 25-35 grams of protein per serving (1 scoop). 

A protein shake is also a great option if you find you aren’t that hungry but still have protein macros left for the day since it is less filling than eating whole food sources of protein like chicken or beef.

Drawbacks of Drinking a Protein Shake Before Bed

1. Could Cause Digestive Upset

Some individuals experience negative digestive symptoms after ingesting a protein shake. Common digestive side effects from protein shakes are diarrhea, constipation, and nausea.

These less-than-ideal digestive symptoms have been reported with the consumption of both whey and casein protein in those who are sensitive to these ingredients. 

With whey protein, digestive symptoms are often attributed to its lactose content, whereas in casein protein, digestive symptoms are likely a result of its slower breakdown in the body which puts strain on the digestive system.

If you’re experiencing digestive issues with casein, then try whey instead. If whey is causing you issues, try switching to a plant-based protein powder like pea protein.

Additionally, some protein shakes contain artificial sweeteners which can negatively affect your gut and digestion. Additives like artificial sweeteners have been shown to disrupt and cause damage to the gut, which can cause digestive symptoms.

Any digestive symptoms from a protein shake would certainly impact the quality of your sleep and limit your potential for muscle growth and recovery.

2. Not As Filling As A Whole Food Protein Source

Drinking a protein shake before bed might not keep you full throughout the night compared to a snack that contains protein from whole foods. 

Whole food sources of protein (like greek yogurt) often contain other nutrients like fat or fiber which can slow down the rate of digestion and keep you satisfied for longer.

If your protein powder isn’t holding you over and it is causing you to wake up hungry then you might be better off having a high-protein snack derived from whole foods, such as a bowl of yogurt with nuts.

However, it’s also important to note that the length of time that a protein shake will keep you full will heavily depend on what type of protein powder you use.

Whey Protein vs Casein Protein Before Bed – Which Is Better?

Drinking a casein protein shake before bed is better than drinking a whey protein shake because casein protein digests much slower than whey protein, which will help to keep you feeling fuller for longer during the night.

Whey protein has an absorption rate of around 10 grams per hour, while casein protein has an absorption rate of around 6 grams per hour.

This slower digestion of casein will also help to ensure that you don’t experience any drastic spikes and falls in your blood sugar during the night, which would negatively impact your sleep. 

Casein protein will also be more beneficial for preventing muscle breakdown while you sleep due to its slow digestion rate which allows for a steady supply of amino acids to your muscles.

Therefore, casein protein is the best protein supplement to consume before bed, as you will be going for an extended period without food.

Conversely, whey protein is digested and synthesized at such a rapid rate in the body that it is best consumed during the immediate hours following a workout. 

If you would prefer to take whey protein as opposed to casein before bedtime, you could try mixing your protein with whole milk, since milk contains protein and fat that will help you to feel fuller for longer, decreasing the likelihood of disrupted sleep.

What Should You Mix Whey Protein with Before Bed?

If you prefer whey protein to casein protein or whole foods but still want to feel full throughout the night and prevent muscle breakdown, then I recommend mixing your whey protein with a food source that contains fat and/or fiber.

Mixing your whey protein with foods that contain fat and fiber will help to slow down the rate of digestion, which will help to keep you full throughout the night. 

For example, nuts and seeds contain both fat and fiber to help keep you full, along with providing additional nutrients such as magnesium, potassium, zinc, and B vitamins.

If you are concerned about going over your calorie targets for the day, you could mix your whey protein with lower-calorie options like unsweetened almond milk or water. 

However, keep in mind that this lower-calorie mixture will digest much more quickly and potentially leave you feeling hungry shortly after or in the middle of the night.

Pre-Sleep Whey Protein Recipe

yogurt bowl

Try this bedtime snack that contains whey protein along with other food ingredients that can help to promote better sleep and improved recovery:

  • 1 scoop of Chocolate Whey Protein
  • ¾ cup Plain 2% Greek yogurt
  • ½ oz almond
  • ½ a banana

Greek yogurt is a great food to include in your bedtime snack alongside your whey protein since it contains casein and fat which will slow down the digestion of the whey. 

Greek yogurt also contains the amino acid tryptophan, which converts into the hormone melatonin (our sleep hormone).

Including almonds in this recipe is beneficial since they are high in magnesium, a mineral that can promote better quality sleep.

Lastly, adding a small amount of banana not only provides a delicious topping to your yogurt bowl, but bananas are high in both tryptophan, magnesium, and potassium, which is another important mineral that can contribute to better sleep and recovery and help with muscle soreness.

Recommended Protein Intake Before Bed

The specific amount of protein that is optimal for you before bed is going to depend on your specific protein requirements along with what you have already consumed during the day.

Stuart M Philips, professor, and researcher at McMaster University suggests a daily protein intake of 0.82  to 1 gram of protein per pound of bodyweight.

For a 120lb individual, an appropriate protein target would be 98 to 120 grams of protein per day.

If you have already met your protein target by dinnertime, then it would not be as beneficial to go over your calorie and macro targets by having a protein shake before bed.

However, if you haven’t met your daily protein target by bedtime then studies have shown that ingesting around 30-40 grams of protein before bed can benefit muscle growth, muscle retention, and recovery.

Frequently Asked Questions

Should You Only Have a Protein Shake Before Bed If You Work Out?

If you haven’t met your protein requirements for the day, you can consume a protein shake before bed, even if you didn’t workout. Consuming a protein shake before bed can improve physical performance, muscle recovery, and muscle building in the body, and can also help you meet your daily protein target.

What Type of Protein Is Best Before Bed?

Consuming a casein protein shake before bed is going to be the best option because casein protein digests at a much slower rate than whey protein. The slower rate of digestion means that you are less likely to feel hungry and have a better chance of uninterrupted sleep.

How Can Protein Before Bed Help Your Muscle Recovery?

Consuming protein before bed can encourage muscle recovery because protein is the macronutrient that contributes to muscle protein synthesis (muscle building). While you sleep, there is a higher potential for muscle breakdown, but consuming protein before bed can help to mitigate this and promote recovery instead.

Can You Mix Whey Protein with Hot Milk?

Yes, you can mix whey protein with hot milk; whey protein dissolves better in hot liquids than in cold liquids. Additionally, mixing a fast-digesting whey protein with milk (which contains casein along with a source of fat), will help you to feel fuller for longer.

What To Read Next


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About The Author

Colby Roy

Colby Roy is a holistic health and nutrition coach. She is certified through Precision Nutrition and has a passion for all things nutrition and healing the body. More specifically, Colby likes to work with clients who want to optimize their gut health and energy levels.

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