“Protein supplementation, including whey, can promote muscle growth, strength, and recovery when paired with resistance training,” says Morgan Walker, RDN, a sports nutritionist at Lebanon valley College in Annville, Pennsylvania.A recent review from Italy supports this, though the authors found results vary based on dose, timing, and overall diet.²

Walker also notes that whey’s muscle-building effects could be beneficial for older adults.A systematic review in Poland found that pairing whey supplementation with age-appropriate exercise may improve muscle mass.³ The Italian review reported similar results, highlighting that whey protein supplements helped maintain muscle mass and prevented sarcopenia in older adults, which can ultimately help prevent falls.²

Whey protein can be beneficial for those who want to gain more weight. And it can be helpful for people with chronic health conditions, swallowing difficulties, or those who struggle to gain nutrients through food alone.¹

Whey protein supplementation may also improve body composition (the balance of lean muscle and fat), according to one meta-analysis from Iran, with the greatest benefits seen when combined with resistance training and moderate calorie restriction.⁴ The aforementioned Italian review similarly found whey protein helped increase lean body mass.