The questions she gets range from “‘Oh are you trying to get ripped?’" to “‘That stuff doesn't do anything’— they seem to think that all you have to do to get built is to swig a protein shake twice a day and muscles will magically appear.”
That is not, for better or worse, how it works.
Most people use protein powder to intake a large amount of protein in a single low-calorie go, usually post-workout. Of course, eating more protein on its own will not build muscle—and just like that Redditor, many consumers of protein powder seem to understand this; they use it as a convenient way to balance out their protein intake at times when they wouldn’t otherwise get “enough” from a day’s meals. But most people get plenty of protein to build muscle through exercise—and eating extra doesn’t build extra muscle.
As my colleague Katherine Foley has written for Quartz, the guidelines for how much protein a person needs are various and conflicting. The National Academy of Medicine recommends that men who are not athletes consume .8 grams of protein per kilogram of bodyweight, while the USDA recommends somewhere around .6 grams per kilogram. But according to David Levitsky, a professor of nutrition at Cornell University, these recommended amounts are likely far more than enough. Even by the National Academy of Medicine’s guidelines, which Levitsky believes are overly high, an average man weighing in at 70 kilograms (or 154 pounds) would need to eat 56 grams of protein per day—that’s just slightly more than what’s found in a salmon fillet or three cups of lentils.
Still, “It is almost impossible to consume lethal amounts of protein,” Levitsky wrote in an email. The liver, he says, is capable of filtering the excess and metabolizing it like a carbohydrate. But Levitsky says this, coupled with the lack of evidence that consuming protein immediately after a workout has any added effect on building muscle, means that protein supplements are essentially a harmless waste of money.
“One of the things that’s pretty prevalent,” Levitsky says, “is the fantastic placebo effect that occurs.” Levitsky claims that those who use protein powder, believing it will help them gain muscle, may be unconsciously more motivated to exert themselves while exercising, creating the effect they hope to see.
If, for some, protein powder is just a benign placebo whose effect is only as powerful as belief, it’s worth considering where those beliefs come from. Jacked bodies are generally considered the ideal for men (excepting the brief celebration of the so-called straight male “dadbod”). And while working out is one of the many ways that women are taught to control their appearance to make themselves desirable, for men, the path to the idealized body almost always leads to the gym. Men are taught not only that getting in shape will make them more attractive, but that doing so is a matter of self-determination.