Eating This Much Protein Before Bed May Help Support Muscle Growth

The idea that eating protein before bed – often called “pre-sleep protein” – can help build muscle while you sleep has merit, but how much should you eat to reap the benefits? Here’s what the experts had to say.

Research suggests that about 40 grams of protein should be consumed to stimulate muscle growth throughout the night, said Mandy Tyler, MEd, RD, a sports nutrition consultant. Several studies have shown that this amount, generally consumed 30 minutes before bed, has beneficial effects on muscle development.

You don’t need to consume an extra 40 grams beyond your usual protein intake. Instead, clinical dietitian Toby Amidor, MS, RD advised making it part of your daily protein goal. According to the International Society of Sports Nutrition, exercising adults should aim to consume between 1.4 and 2.0 grams of protein per kilogram of body weight per day. For a 150-pound person, that’s 95 to 136 grams per day. Forty grams of protein before bed would be 29-42% of this range.

Just note that for some people, eating a large amount of protein before bed could cause gastrointestinal upset and ultimately disrupt sleep. “These people may need to experiment with the timing and type of protein-rich foods eaten before bed,” Tyler said.

If you don’t eat before bed, no new dietary amino acids enter your bloodstream during the overnight fast. But having protein before bed allows for a steady release of amino acids while you sleep, since digestion continues throughout the night. These amino acids can stimulate muscle protein synthesis and improve net muscle protein balance – the difference between building muscle and losing muscle.

Still, it all depends on the type of protein you eat, Amidor said.

The two types that most support overnight muscle growth are casein and whey, found in dairy products like cottage cheese and milk, and which provide all the amino acids your body needs. “Both casein and whey contribute to muscle building, maintenance and recovery,” Amidor said. “However, everyone works a little differently.”

Whey protein, one of the most concentrated sources of leucine, an amino acid responsible for building muscle, digests faster than casein and releases amino acids into muscles more quickly. Some research suggests that when consumed before bed, whey protein may help rebuild connective tissue overnight.

Casein, on the other hand, digests more slowly and releases its amino acids more gradually into your muscles. Despite its slower release, research has shown that casein promotes muscle growth overnight. A 2021 study found that consuming 20 to 40 grams before bed boosted whole-body protein synthesis rates in both young and older men.

To get the most out of a pre-sleep protein routine, Amidor recommends consuming a combination of whey and casein proteins.

Another key way to maximize the benefits of protein at bedtime is to incorporate a strength training workout into your day, whether early or in the evening (some research suggests that strenuous exercise before bed can disrupt sleep, so you may want to keep it gentle). “The combination of strength training and protein before sleep appears to further increase muscle growth overnight,” Tyler said.

Strength training involves using resistance, such as body weight or free weights, to make you stronger. Examples include squats, push-ups, lunges, and planks.