Protein is a macronutrient known for aiding muscle growth, athletic performance and recovery while helping to keep you feeling full. However, research suggests protein could also help you sleep better.
So, while you’re whipping up your next shake using one of the best protein shakers, we looked more closely at the existing and emerging evidence. According to nutritional therapist Kerry Beeson (BSc) at Prep Kitchen, if your sleep hygiene needs a boost, you might want to examine your protein intake more closely.
Can protein improve sleep quality and reduce sleep disturbances? Here’s what we know.
Protein and sleep: what's the connection?
Protein is one of three macronutrients you need to stay healthy, alongside fats and carbohydrates. It's most well-known for helping you build and maintain muscle mass.
If you’re a macro-tracking beginner, protein provides your body with amino acids, which play a key role in neurotransmitter production, helping with mood regulation and relaxation. There’s one particular amino acid — tryptophan — that contributes to sleep regulation.
“Tryptophan is a precursor to serotonin, a neurotransmitter that helps produce melatonin, the hormone responsible for regulating our sleep-wake cycle,” Beeson explains. “Consuming protein-rich foods that contain tryptophan may enhance melatonin production, ultimately improving sleep.”
Beeson adds that the RDA (recommended daily allowance) for tryptophan is 250 to 425 mg per day for the average adult. It's found in foods like poultry, meat and fish, dairy, eggs and plant-based proteins such as tofu, legumes, nuts, seeds and whole grains.
Great news for those with a sweet tooth, as dark chocolate is also tryptophan-rich!
Kerry is a qualified nutritional therapist, with a BSc in nutritional medicine. Her training encompasses naturopathy, nutritional therapy, functional medicine and kinesiology. She is also a gut health expert and metabolic balance coach.
Blood sugar and sleep: what’s the connection?
It’s widely thought the average person without a blood sugar health condition (like diabetes) shouldn't need to monitor theirs every day — hello to the rise of biohacking your metabolism with continuous glucose monitoring (CGM).
However, awareness of how blood sugar regulation impacts your health has its uses, including for your sleep quality.
Research — like this study — suggests large spikes and crashes (sometimes caused by high-carb, low-protein meals) could lead to sleep disturbances and restlessness. “One of the key ways that protein and sleep quality are linked is through blood sugar stabilization,” Beeson says.
“When consumed with carbohydrates, protein slows digestion and the release of glucose into the bloodstream, reducing sharp spikes in blood sugar. This helps prevent the night-time blood sugar crashes that can wake you up or cause restless sleep.”
And studies, like this one published in the American Journal of Clinical Nutrition, suggest an increase in protein could improve blood glucose responses in those with type 2 diabetes.
There’s another reason to add a balanced macronutrient meal to your evening routine: energy release. A slow, steady release of energy can help prevent large spikes and crashes or overnight hunger pangs that may wake you up.
“A high-protein diet and sleep benefits may also be linked to improved insulin sensitivity, which means better blood sugar regulation throughout the day and night,” Beeson adds.
When is the best time to take protein?
The best time to consume protein depends on your lifestyle and sleep patterns, so it may not look the same for everyone. However, there are a few guidelines you can follow.
“Consuming protein powder and sleep-supporting foods before bed may benefit muscle recovery and sleep. Whey protein and sleep benefits have been studied in athletes, with some findings suggesting improved overnight muscle protein synthesis and better recovery,” Beeson says.
“There is a lot of interest in casein protein for sleep. It is a slow-digesting protein, so…before bed may help provide a steady release of amino acids throughout the night, reducing muscle breakdown and promoting deeper sleep.”
One randomized controlled trial on older men found ingesting 40g of protein before sleep could increase myofibrillar protein synthesis rates during overnight sleep, which could help maintain muscle mass as you age alongside preventing atrophy.
However, for some, eating close to bedtime can cause discomfort and may disrupt digestion. It's best to look at your personal routine and decide when to eat your last meal.
Protein is one of three macronutrients you need to stay healthy, alongside fats and carbohydrates.
“Some people find that distributing protein intake evenly across meals ensures a consistent supply of amino acids,” Beeson says. This helps support neurotransmitter function and the sleep-protein balance, plus keeps you feeling full after each meal, which is also optimal for those looking at fat loss.
So don't worry, if you consume “optimal” protein during the day, this could still improve sleep quality. As for how much protein to consume, protein requirements differ from person to person, depending on factors like age, sex and activity levels. Only aim for protein intake that supports your needs.
“While protein is essential, excessive intake right before bed, particularly from heavy meals, may cause digestive discomfort, disrupting sleep rather than improving it,” warns Beeson. “It's best to find a balance.”
Verdict: can protein help you sleep?
“The evidence suggests that protein intake and sleep may be connected. Whether through its role in neurotransmitter production, its ability to stabilize blood sugar, or its support for muscle recovery overnight,” Beeson explains.
While adequate protein intake could potentially improve sleep quality, consider the protein sources you use, when you consume them and what works for your lifestyle and needs.
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