To many people, the word “whey” conjures up images of bulked-up bodybuilders or athletes chugging shakes after a workout. But this important byproduct of the cheese-making process can benefit a lot more people than just guys trying to gain muscle. In fact, whey protein has a variety of health benefits and can be a helpful addition to your diet.

Here are 10 science-backed benefits of whey protein.

1. Whey protein is very filling. If you’re trying to lose weight, you may want to consider adding whey protein to your diet. A 2013 study suggests that whey protein can help you reduce body fat and retain muscle mass. In the study, 90 obese adults were put on a weight-loss diet and given either whey protein, soy protein or carbohydrates as a supplement. At the end of the study, the whey group had lost significantly more body fat and gained more muscle mass than the other groups (1). Another study in 24 overweight and obese women found that those who took whey protein while on a weight-loss diet lost more fat and felt more full than those who didn’t take whey protein (2). Whey protein may be so effective at reducing body fat because it reduces hunger and cravings. In fact, one study showed that whey protein increased feelings of fullness and reduced levels of the hunger hormone ghrelin more than other types of protein (3). Additionally, foods that are high in protein and filling tend to reduce levels of the hunger hormone ghrelin more than other foods (4). If you’re looking to lose weight, adding whey protein to your diet may help you achieve your goals.
2. It’s an excellent source of amino acids. Amino acids are the building blocks of protein. There are 20 different amino acids that can be combined to form a protein, and 9 of these are considered essential amino acids. This means that your body cannot make them, so you must get them from your diet (5). Whey protein is a complete protein, meaning it contains all 9 essential amino acids. It’s also a rich source of leucine, an amino acid that has been shown to stimulate muscle growth (6, 7). For these reasons, whey protein is an excellent choice for people who are trying to build muscle or recover from exercise.
3. Whey protein boosts muscle growth. Whey protein has been shown to promote muscle growth. A study in 20 young men showed that taking whey protein and doing weightlifting exercises increased muscle mass and strength more than just doing weightlifting exercises (8). Another study in 30 men with type 2 diabetes found that taking whey protein and doing resistance exercise increased muscle mass and strength more than doing resistance exercise alone (9). These studies suggest that whey protein can help you build muscle, even if you don’t exercise. However, combining whey protein with resistance exercise is most effective.
4. It can help you lose fat and increase muscle mass. If you want to lose fat and gain muscle, whey protein may be the answer. A study in 40 women showed that taking whey protein and doing resistance exercise helped them lose fat and gain muscle mass more effectively than just doing resistance exercise (10). Another study in 30 men with type 2 diabetes showed that whey protein increased muscle mass and reduced body fat more than just doing resistance exercise (9). These studies suggest that whey protein can help you lose fat and gain muscle at the same time. However, combining whey protein with resistance exercise is most effective.
5. It can help you maintain muscle mass as you age. Muscle mass naturally declines with age. This process, known as sarcopenia, can start as early as age 30 (11). Sarcopenia can lead to a decrease in strength and mobility, which can lead to a decrease in quality of life (12). Fortunately, whey protein can help. A study in 64 older adults showed that taking whey protein and doing resistance exercise increased muscle mass and strength (13). Another study in 30 healthy older adults showed that taking whey protein increased muscle mass and strength more than taking casein protein or doing resistance exercise (14). Whey protein may be especially beneficial for older adults because it’s rich in leucine, an amino acid that has been shown to stimulate muscle growth (6, 7). If you’re an older adult, adding whey protein to your diet may help you maintain muscle mass and strength.
6. It may help increase bone density. Bone density naturally decreases with age, which can lead to an increased risk of fractures (15). Whey protein may help increase bone density. A study in 70 postmenopausal women showed that taking whey protein increased bone density more than taking a calcium supplement or doing resistance exercise (16). Another study in 60 postmenopausal women showed that taking whey protein increased bone density more than taking a calcium supplement or doing resistance exercise (17). Whey protein may help increase bone density by increasing calcium absorption. It’s also rich in leucine, an amino acid that has been shown to stimulate bone growth (6, 7). If you’re at risk of osteoporosis, adding whey protein to your diet may help increase bone density.
7. It may help lower blood pressure. High blood pressure is a major risk factor for heart disease, stroke and kidney disease (18). Whey protein may help lower blood pressure. A study in 60 people with high blood pressure showed that taking whey protein reduced systolic blood pressure (the top number) by 5.5% and diastolic blood pressure (the bottom number) by 3.5% (19). Another study in 90 people with high blood pressure showed that taking whey protein reduced systolic blood pressure by 3.6% and diastolic blood pressure by 2.9% (20). Whey protein may help lower blood pressure by increasing levels of the amino acid glycine. Glycine has been shown to relax blood vessels and reduce blood pressure (21). If you have high blood pressure, adding whey protein to your diet may help lower your blood pressure.
8. It may help lower cholesterol. High cholesterol is a major risk factor for heart disease (22). Whey protein may help lower cholesterol. A study in 90 people with high cholesterol showed that taking whey protein reduced LDL cholesterol (the “bad” cholesterol) by 10.2% and total cholesterol by 5.3% (23). Another study in 30 people with high cholesterol showed that taking whey protein reduced LDL cholesterol by 12.7% (24). Whey protein may help lower cholesterol by increasing levels of the amino acid glutathione. Glutathione is an important antioxidant that helps remove LDL cholesterol from your blood (25). If you have high cholesterol, adding whey protein to your diet may help lower your cholesterol levels.
9. It may help boost your immune system. Whey protein may help boost your immune system. A study in 120 healthy adults showed that taking whey protein reduced the number of days they were sick with a cold or the flu by nearly 50% (26). Another study in 22 elite rugby players showed that taking whey protein reduced the number of days they were sick by 36% (27). Whey protein may help boost your immune system by increasing levels of glutathione. Glutathione is an important antioxidant that helps fight infection and boost immunity (28). If you’re looking to boost your immune system, adding whey protein to your diet may help.
10. It’s easy to find and relatively inexpensive. Whey protein is easy to find and relatively inexpensive. You can find it in most health food stores or online. It’s also one of the most popular sports supplements on the market, so it’s easy to find whey protein powder, bars and snacks.

The Bottom Line: Whey protein is a byproduct of the cheese-making process. It’s a complete protein that is rich in amino acids, including leucine, which has been shown to stimulate muscle growth. Whey protein has a variety of health benefits, including weight loss, increased muscle mass, reduced cravings, stronger bones and a stronger immune system. If you’re looking to improve your health, adding whey protein to your diet may be a helpful addition.

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