Study Finds Eating More Protein Doesn’t Benefit Everyone

With keto and paleo diets grabbing headlines and pushing more protein onto plates across the country, it’s easy to think that an extra helping of meat (or other protein-rich foods) is good for you. But current guidelines suggest you only need .8 grams of protein per kilogram of bodyweight daily. So what’s the right move? Nutrition scientists at Purdue University have an answer. In a new study published in Advances in Nutrition, they conclude that eating more than the recommended amount of protein only benefits people who are actively trying to lose weight or build muscle. Everyone else should stick with the .8-gram guideline.

“Most adults who are consuming adequate amounts of protein may only benefit from moderately higher protein intake when they are purposefully trying to change their body composition,” study co-author Wayne Campbell said in a Purdue news post.

The researchers set out to determine if adults would benefit from eating more protein than the daily guidelines suggest. It’s an important point to investigate because most adults already eat more protein than is recommended, study co-author Joshua L. Hudson said. To find an answer, the researchers combed through more than 1,500 published journal articles and picked out 18 studies, which assessed a combined total of 981 participants for the meta-analysis.

Then they zeroed in how protein intakes above the recommended daily amount (RDA) affected the participants’ body mass, and how that compared with participants who consumed protein in line with the RDA. It’s the first meta-analysis comparing above-RDA protein consumption with RDA protein intake, according to the published article. Interestingly, the researchers found that eating more protein had no effect on the body composition of adults who weren’t dieting or exercising to build muscle mass.

They did, however, find that eating more protein helped adults who were dieting to lose weight or working out to build muscle—the added protein helped them build lean mass. Based on that data, the researchers came up with some advice for people who are dieting: Don’t just eat less.

“Instead, work to maintain, or even moderately increase, protein-rich foods,” said Campbell. “Then, cut back on the carbs and saturated fat-containing foods.”

Likewise, if you’re working out in order to bulk up, eating more protein than the RDA will help you build lean muscle mass. But if you’re not trying to change your body too much, then it’s a good idea to stick with the RDA, because eating more protein won’t offer any benefits.

“There is so much encouragement, advertising and marketing for everyone to eat higher protein diets,” said Hudson. “This research supports that, yes, under certain conditions, including strength training and weight loss, moderately more protein may be helpful, but that doesn’t mean more is needed for everybody at all times.”