Isaac Robertson
Published by Isaac Robertson
Fact checked by Donald Christman, BHSc FACT CHECKED
Last updated: May 19, 2021

Protein shakes are one of the most popular supplements among young and healthy athletes, gym enthusiasts, and bodybuilders.

Since mornings are the best time for workouts and protein shakes are the most efficient when taken after the workout, protein shake has replaced the typical breakfast. But they double as excellent pre-sleep drinks, too.

Our resident dietitian explains why this is the case.

Benefits of Drinking a Protein Shake Before Bed

Drinking a protein shake after a hard workout is an excellent way to supplement your muscles and enhance their recovery, but chugging one before bed may be even more efficient.

Here are the benefits of drinking a protein shake before bed.

Promotes Muscle Growth and Preservation

woman flexing her biceps

Drinking a protein shake at bedtime promotes overnight muscle protein synthesis (MPS), which is a biochemical process crucial for growing muscles.

If you’re an active gym goer, your muscles continuously go through cycles of MPS and MPB (muscle protein breakdown) [1].

However, continuous resistance training accelerates MPB.

Taking a protein shake before bed helps your body maintain a positive protein balance during this cycle, which is essential for building your muscle.

Your muscle growth decreases while sleeping, leading to MBP. But if you take enough protein before sleep, your chances for preserving and building muscle at rest increase immensely.

Amino acids present in protein are the building blocks of muscle mass.

When you work out more, the levels of amino acids decrease so you need to balance them out with a high-protein diet, and a protein shake before bed can help you with that.

One study revealed that a protein shake consumed before bed is better absorbed in people who workout in the evening [2]. The study concluded that:

“Physical activity performed in the evening augments the overnight muscle protein synthetic response to presleep protein ingestion and allows more of the ingested protein-derived amino acids to be used for de novo muscle protein synthesis during overnight sleep in older men.” — Andrew M Holwerda et al, Physical Activity Performed in the Evening Increases the Overnight Muscle Protein Synthetic Response to Pre Sleep Protein Ingestion in Older Men

Improves Recovery

man doing stretches outdoors

Another study discovered that taking a protein shake before bed improves post-exercise recovery [3].

The study included 16 healthy young men who did some resistance-training in the evening.

They consumed either 40 grams of protein or placebo before sleep.

The results revealed that the participants who took protein had increased whole-body muscle protein synthesis rates and improved net protein balance compared to the participants who took placebo.

Moreover, the results also showed that protein was more effectively digested and absorbed in the evening.

Promotes Better Performance

shirtless man using a bar at a park to do pullups

Drinking a protein shake before bed may also enhance your athletic performance.

Besides strength and muscle growth, a pre-sleep protein shake also regulates the muscle protein metabolism.

Moreover, it can also:

  • Enhance overnight muscle reconditioning
  • Improve strength during workouts
  • Increases lean muscle mass
  • Provides you with the ability to exercise longer
  • Improves muscle adaptation to exercise training

However, it has been established that consuming 40 grams of protein per day doesn’t promote recovery or performance after a daytime workout.

Improves Energy Levels

A lean muscle mass increase can boost your energy levels, which will allow you to exercise for longer.

According to a 2016 study, drinking 40 grams of protein shake before bed enhances the skeletal muscle adaptive response [4].

Consuming protein before bed promotes muscle repair and reconditioning, which leads to increased strength.

Accelerates Weight Loss

woman using a measuring tape on her body

This may be hard to believe, but if you’re trying to lose a couple of pounds, you may want to drink a protein shake before sleep.

Doing this will help you burn calories even while you’re sound asleep.

Drinking protein shakes not only promotes muscle protein synthesis, but it also pushes your metabolism into overactivity.

Your body will need more energy to absorb and digest the protein you took before bed, hence burning calories even as you sleep, and finally, leading to weight loss.

Of course, if you’re trying to lose weight you’ll have to watch your calorie intake.

For example, if you mix 40g of casein protein powder in a glass of water, you’re adding 160 calories to your daily diet. That’s four calories per gram of protein.

However, if you mix the protein with milk or even fruit, your calorie intake will go up, and may even lead to unwanted weight gain.

Furthermore, protein ingestion suppresses hunger by suppressing the hunger hormone — ghrelin, and promoting the satiety hormone leptin.

This will make you feel less hungry, which will make you eat less, and as a result you’ll lose weight.

Moreover, low-protein weight loss programs typically lead to sagging skin because of the muscle tissues break down.

Pre-sleep protein intake can prevent skin from sagging, which is a very common side effect of weight loss.

Enhances Sleep Quality

man in deep sleep laying down

Pre-sleep protein ingestion can promote your sleep quality by pushing the amino-acid tryptophan into your system.

The amino-acid tryptophan enhances the production of serotonin — the happy hormone, and melatonin — the sleep-inducing hormone.

You can mix the protein powder in soy milk, regular milk, or Greek yogurt — all rich sources of tryptophan.

Types of Protein Powders to Drink Before Bed

close up image of a protein scattered protein powder with a scooper

As you know, there are different types of protein powders — soy, casein, and whey, among others. All these stimulate muscle growth, but in different ways.

Your body digests whey protein fast, providing instantaneous muscle protein synthesis. Because of this, whey is the best post-workout shake.

On the other hand, your body digests soy and casein slowly, prolonging the muscle protein synthesis through the night.

Both when and soy protein are great pre-bed protein options, but since whey is digested more slowly, it’s the best out of the three options.

Who Should Drink Protein Before Bed?

man and woman chugging a protein shake in a gym

You may want to consider consuming a protein shake before sleep if you:

  • Want to enhance your muscle growth or improve your performance
  • Workout regularly
  • You already consume enough protein
  • Are healthy

On the other hand, if your goals don’t include muscle growth or enhanced performance, taking casein protein before sleep may not be worth the hassle. Moreover, slow-acting protein, such as whey, is more efficient for people who workout later in the day.

However, if you have diabetes or insulin resistance, you may be better off not eating before bed.

Cons of Taking Protein Before Bed

woman with her thumbs down while holding two jugs

So far, I talked about the pros of drinking protein before bed: 

  • Helps you grow and maintain your muscle mass
  • Provides improved overnight recovery
  • Enhances energy and performance levels
  • Increasing your net protein balance
  • Helps with weight loss
  • Promotes sleep quality

But, no matter the pros, consuming protein shakes before sleep also comes with a few cons:

It Might Mess up You Circadian Rhythm

man laying down in bed in panic with his alarm clock beside

Your body has natural 24-hour rhythms, known as circadian rhythms. Besides affecting your sleep schedule, they also control your hormone levels.

Disturbed, inconsistent, or mismatched circadian rhythms are associated with higher rates of heart disease, mental health issues such as depression, and cancer.

This can typically be observed in nighttime workers.

Light exposure is the most significant factor in determining your circadian rhythms, but food intake also affects the cycles.

For  example, late meals can impact your 24-hour hormonal profile.

So, while pre-bed protein intake can be temporarily useful for muscle building or promoting your performance and energy levels, it probably wouldn’t be wise to practice this long-term.

Increased glucose and insulin levels

Eating carbs before bed may elevate your insulin and glucose levels, resulting in insulin resistance, which is closely related to the development of type 2 diabetes.

Similarly to carbs, whey protein also increases your insulin levels.

While the insulin spike from whey is helpful for post-workout muscle-building, you may want to pay attention to your health.

There’s currently no evidence that whey protein leads to insulin resistance, but you may want to stay on the safe side, just in case.

Slows Down Fat Oxidation and Metabolism

woman holding her belly

As we already discussed, research suggests that pre-bed casein protein doesn’t reduce fat-burning, but drinking whey protein before bed does.

In the same way, eating any food, before bed or otherwise, lowers fat-burning compared to avoiding food.

So, if you want to maximize fat-burning, the safest way is to skip pre-bed meals.

Or, at least make sure to avoid carbohydrates for a few hours before sleep.

FAQs

Is It Ok To Drink Protein Shake Without Working Out?

Absolutely — yes! Shakes are a convenient way to ensure you’re taking in enough protein. However, if your physical activity levels are low, your meals may already meet your protein needs.

What Protein-Rich Food Can Improve Muscle Growth During Sleep?

Cottage cheese, nuts, yogurt, poultry, tofu, seafood, legumes, and lentils are excellent high-protein sources that’ll help you increase muscle mass.

How Many Glasses of Protein Shake Can You Have in a Day?

Typically, you need 0.5 grams of protein per pound of body weight. However, you exercise regularly, you need more —  about 0.7 to 0.8 grams per pound of weight. Eating protein-rich food should help you achieve this goal, but you may add dietary protein if you feel like you don’t get enough from your food.

Depending on your deficit, you could consume one or two glasses of protein supplement per day. About 40 grams of casein protein should provide you with optimal benefits.

Should You Take A Protein Shake Before Bed?

Pre-bed protein consumption brings a lot of benefits, such as muscle gain, better sleep, muscle strength, more energy, better and faster recovery, and improved performance.

However, it’s important to drink the right protein shakes. I’d recommend a casein protein powder, as its digestion is the slowest, so it provides most MPS.

How many grams of casein you’ll take a day depends on your body weight.

Just make sure you count your daily protein intake into your daily calories to avoid the weight gain.

What are your thoughts on pre-bed protein? Share them in the comments!


References:

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3381813/
  2. https://academic.oup.com/jn/article/146/7/1307/4585779
  3. https://journals.lww.com/acsm-msse/Fulltext/2012/08000/Protein_Ingestion_before_Sleep_Improves.20.aspx
  4. https://www.mdpi.com/2072-6643/8/12/763

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