You may have had a glass of milk before bed as a kid to build strong bones, but did you ever think that this night-time drink may also be useful for better gym gains? Here, we take a look at the evidence surrounding protein shakes before bed and provide some practical guidelines to avoid any potential pitfalls.
Benefits of Protein Before Bed
1. Weight Loss
Protein is the main nutrient that stimulates the growth of new muscle tissue and also helps to protect your hard-earned muscle mass during weight loss.(10) However, the power of protein doesn’t stop there, as research shows that protein intake before you hit the hay can boost metabolism (the process of converting food into energy) and help keep hunger pangs at bay. This is important as, to lose weight, we must burn more calories than we consume throughout the day.
Fascinatingly, protein intake before you go to bed has been shown to increase your metabolism the following day, meaning you’re burning around 100 extra calories, simply through what you have before bed the previous night.(8, 9, 11)
Furthermore, the body uses far more energy to digest, absorb, and metabolise protein compared to when you eat carbohydrates, meaning that a late evening protein snack can also increase metabolism throughout the night.(1) Finally, protein intake also keeps us feeling full and may help to reduce those late-night, high calorie cravings that can be so damaging to your weight loss success.(2)
So, this all means that protein prior to sleep can increase energy expenditure throughout the night and throughout the next day, whilst also stopping us from picking up those late-night snacks that can have a huge impact on our weight loss goals.
It’s still pretty unclear whether a particular form of protein is better than another for speeding up metabolism. Most studies currently conclude that larger portions may be better, given that a 48g helping appears to increase resting energy expenditure to a greater extent when compared with 24g (i.e. two servings versus one).(8)
2. Muscle Growth
While many people train in the evening and consume protein in the post-workout period, how many of us consider protein shakes before bed? This is especially important given that the stimulation of muscle growth is typically low when you sleep and so you may be at risk of muscle protein breakdown throughout the night. (3, 15)
Luckily, researchers have shown that your gut is still able to function normally throughout the night whilst you sleep, which means you can still properly digest and absorb any protein consumed before bed.(5) This gives you a clear opportunity to stimulate muscle growth as you sleep by slurping down protein shakes before bed.
So how much do you need? Researchers have shown that 40g casein protein before bed stimulates muscle protein synthesis (the process of building muscle mass) by around 20%.(12)
Doing so provides conditions that are favourable for muscle growth, as it takes our muscle from a state of negative protein balance to a state of positive protein balance, meaning that we are synthesising more muscle than we are breaking down. These researchers have also shown that protein shakes before bed also lead to changes in both muscle size and strength when combined with regular training. (14)
For instance, those who regularly had protein shakes before bed increased their 1 rep max scores (across a range of 6 different exercises) by 150kg, which is 30kg more than those who consumed no protein before sleep. These adaptations also extended to a 10% increase in quadriceps size and 12% in the number of ‘fast twitch’ type II muscle fibres. These fibres can generate high amounts of force and are relied upon when lifting weights
Sleep is generally recognised as an important recovery tool and a constant lack of sleep may result in changes to performance, immunity and protein absorption.(6)
Although much more research in this area is required, we currently know that consuming a high-protein diet may improve overall sleep quality.(7) Furthermore, its intake prior to sleep may increase the availability of the amino acid L-tryptophan. When consumed with carbohydrates, tryptophan uptake into the brain is increased and may improve the time taken to fall asleep as well as overall sleep quality.(6)
Which protein to consume before bed
The majority of available research to date supports the use of casein protein, although the differences between casein, whey, and soy are very small. The theory behind the use of casein protein is that it provides a more sustained release of amino acids and so maintains amino acid availability throughout the night.(4)
It also appears to have a clearer effect on next-day energy expenditure and seems to have a more satiating effect, meaning it will leave us feeling fuller after drinking.(1)
Despite this, more research is needed to provide clear guidelines on the best form of protein to take before bed. For now, we should keep in mind that the majority of studies listed above commonly use doses between 40-50g protein. It may be that the dosage is a more important consideration than the type of protein being consumed.
Bedtime Protein Recipe Suggestion
Protein plays a role in stimulating the synthesis of new muscle and next-day metabolism, and tryptophan in the production of improved sleep quality and melatonin (the hormone that regulates the sleep–wake cycle). It therefore seems logical that our pre-sleep shake should contain both protein and tryptophan.(13)
Dairy products such as milk and yoghurt provide a mix of both whey and casein, whilst also containing tryptophan, which can be found in pumpkin and sunflower seeds. This pre-sleep shake recipe combines all of the key compounds to cover all bases.
- 150g fat-free strained Greek yoghurt
- 20g protein powder
- 2 tbsp. pumpkin seeds
- 1 cup mixed berries
- Milk or water for desired thickness
Take home message
Having protein shakes before bed provides a key opportunity to stimulate muscle growth, influence daily energy metabolism, and improve overall sleep quality. Furthermore, when consumed regularly, pre-sleep protein promotes gains in both muscle mass and strength. Whilst the optimal type of protein required before bed remains unclear, a dose of between 40-50g may be necessary to achieve the benefits outlined in this article.