Whey is one of two types of protein found in milk (along with casein) and it's among the most well-researched dietary supplements. When used correctly, it can be helpful for building lean muscle mass, promoting recovery, and more. Here's what to know about the main benefits of whey protein, how it compares to other protein sources, the best whey protein for beginners, tips for timing your whey intake, and more.
Types of whey protein.
Whey is the clear liquid portion of milk left over from the cheese or yogurt manufacturing process after coagulation and curd removal.
There are three main types of whey protein: concentrate (WPC), isolate (WPI), and hydrolysate (WPH). WPC contains 70 to 80% protein and is the least processed form3, retaining some lactose and fat content and other nutritional value. WPI is a more processed form of whey, comprising 90 to 95% protein and less than 1% lactose4, making it a safer option for people with lactose intolerance.
WPH is free from fats, carbs, and lactose and contains the highest protein content. In addition, WPC has been shown to enhance fat mass reduction more than other forms of whey protein, according to a 2019 meta-analysis published in 5Nutrients5. However, it's the most processed form with the least nutritional value.
Whey protein benefits:
It's a source of high-quality protein.
It may improve your body composition.
Other research10 has found that whey protein can improve body composition and reduce risk factors for cardiovascular disease in overweight and obese people. But, again, to get the most body composition benefits out of your whey protein, pairing it with resistance training and eating at a slight calorie deficit is ideal.
It may help you gain muscle.
"Whey is often considered the gold standard for its ability to maximally stimulate protein synthesis for the least amount of protein. This is because it is well absorbed and has a very high leucine content," Eric Williamson, Ph.D., R.D., a registered dietitian, exercise nutrition expert, and founder of Unlocked Fitness and Nutrition, tells mindbodygreen.
"Leucine is important because it triggers muscle protein synthesis. This has made whey protein the most popular supplement form of protein for building muscle mass and other adaptations to exercise," Williamson adds.
It may help you lose fat.
It's highly satiating.
It may lower blood pressure.
High blood pressure (also called hypertension) can jeopardize cardiovascular health by increasing risk of stroke, heart attack, chronic kidney disease, and vascular dementia.
It may help to treat Type 2 diabetes.
Research shows whey protein may be an effective supplement for helping to treat Type 2 diabetes. Type 2 diabetes is a chronic condition characterized by high blood sugar levels and impaired function of the hormone insulin that allows cells to absorb blood sugar.
It may strengthen your immune system.
How it compares to plant protein.
"Like any animal protein, whey has a more complete amino acid profile than plant proteins like pea and soy. This means it has sufficient amounts of all amino acids to stimulate protein synthesis at a lower dose than pea or soy," states Williamson.
Who should take it?
Dietary supplements, such as protein powders, should only be used as the name indicates: to supplement an already well-balanced diet.
With that said, supplements like whey protein can be an excellent option for helping to fill in nutritional gaps and meet daily protein needs.
This is especially true if your fitness goal is to build muscle or enhance athletic performance. The American College of Sports Medicine (ACSM) recommends athletes and highly active people consume between 1.2 and 2.0 grams of protein per kilogram (g/kg) of body weight daily—significantly more compared to the current recommendation of 0.8 g/kg of body weight daily27.
"Anyone who has difficulty meeting their protein needs could benefit from consuming a protein supplement like whey," says Williamson. "Those participating in regular intense exercise and those in a calorie deficit to lose weight may particularly benefit from protein supplementation because their protein requirements are higher."
How to find a good option.
Whether you prefer whey protein concentrate, isolate, or hydrolysate, choosing a high-quality supplement is crucial. "Ensuring your protein supplement has been third-party tested can help ensure the product is pure and does not contain banned substances," says Williamson. When looking for a high-quality protein powder, choose an unsweetened, sugar-free product with few added ingredients to reap the most health benefits possible.
Timing & best practices.
Following these protein best practices can help you get the most out of your whey protein:
- Consume your protein across three or four meals spread across the day.
- Aim to get 25 to 30 grams28 of high-quality protein at each meal.
- Take a whey protein supplement that contains at least 3 grams of the amino acid leucine following a resistance training workout for optimal muscle protein synthesis12.
- Consuming protein within 120 minutes following intense exercise can be helpful to support the recovery process.
Side effects & risk of too much protein.
Regularly consuming more than 2.0 grams of protein per kilogram of body weight daily can possibly lead to digestive, kidney, and vascular health issues29.
"Too much protein could lead to inadequate consumption of other important nutrients like fat, fiber, carbohydrates, vitamins, and minerals," says Williamson. "For example, if you experience constipation, you may be consuming too much protein instead of adequate fiber."
Depending on your overall diet, side effects of too much protein can include:
- Impaired kidney function in people with kidney disease
- Increased risk of heart disease
- Elevated LDL ("bad") cholesterol
- Bad breath
Frequently Asked Questions
Is it good to drink whey protein every day?
Whey protein is safe for daily consumption. However, dietary supplements like protein powders should only be used to supplement an existing healthy diet.
What are the benefits of whey protein for runners?
Runners can benefit from whey protein since it's a complete protein source containing all nine essential amino acids, including the branched-chain amino acids (BCAAs) vital for muscle growth and recovery. Also, whey protein is easy to digest and readily absorbed in the blood and muscle, making it an excellent option for refueling after a run.
Does whey protein reduce belly fat?
While it won't target belly fat specifically, you can use whey protein for weight loss and increased fat-burning while retaining lean muscle. "Higher protein intakes can lead to greater satiety, causing you to eat less," explains Williamson. "Higher protein diets in a calorie deficit help maintain lean mass, meaning more weight loss will come from body fat."
Whey protein is a complete protein source that helps to build muscle, promote fat loss, and enhance body composition. Introducing a high-quality whey protein powder into your routine is a great way to work more protein into your diet and experience the health benefits that come with it. Just make sure you're getting plenty of protein from whole foods, too.
Adam Meyer is a health writer, certified holistic nutritionist, and 100 percent plant-based athlete. He graduated from the NutraPhoria School of Holistic Nutrition in 2019 and has since founded Pillars Nutrition. His work has been featured on EatingWell, Eat This Not That!, The Beet, Verywell Fit, The Healthy, Livestrong, Alive, Best Life and others.
Adam lives in British Columbia, Canada, with his wife, two kids and an Australian shepherd. That's where you can find him running mountain trails, working out in his home gym, or writing in a coffee shop.