Science Discovers How Much Protein You Need

How many grams per day? A giant meta-study comes up with a definitive answer for lifters.

The First Protein Powders

Lifters started using protein powder in the 1950’s and the first guy to start manufacturing it for the sweaty masses was a guy from Chicago named Irving Johnson, who later moved to Beverly Hills, California, and changed his name to Rheo H. Blair.

Rheo was soon rolling in it – both protein powder and money. Girls could always tell when their roommates had been over to Rheo’s because they’d come home, get undressed, and a small tell-tale cloud of protein powder would explode into the air when they were undressing and their stockings and panties hit the floor.

Okay, maybe not, but it’s the vision that comes to mind. Anyhow, all the big-name lifters and entrepreneurs got into the game. Bob Hoffman started producing protein powder. So did Joe Weider, and Peary Rader.

Hoffman’s product, however, muscled its way to the top. It was called Hi-Proteen and it was made from soybeans, which is a protein source no modern lifter would touch with a 7-foot Olympic bar/pole. (Here’s why: Avoid Soy Protein.)

The Origin of Protein Recommendations

Hoffman and his associates were ruthless marketers and they relentlessly ran articles about protein requirements. They told people to eat six high-protein meals a day, each one accompanied by protein powder.

Skinny guys were told to pound down a gallon of whole milk a day, filled with so much protein powder that you could pour it into a bucket around a stoolie’s feet, let it dry, dump him into the river, and never see him again.

Likewise, any supposedly savvy lifter was supposed to carry a protein thermos with him every day so that they wouldn’t start shrinking while working on the Willoughby account. And just for insurance, they were told to jam their suit pockets with Hoffman’s protein tablets and munch on them throughout the workday.

There were no specific recommendations for protein requirements for lifters other than “a lot.” Oddly enough, we don’t seem to have collectively gotten all that much closer to figuring out what the optimum amount is, either.

Recommendations are all over the place, some supposedly college-degreed dietitians even doubting the need for any additional protein beyond the RDA (0.8 grams per kilo per day) for weightlifters and bodybuilders.

The age of uncertainty might be over, though. A Canadian exercise scientist from McMaster University has recently published the results of his meta-study on protein requirements for resistance training and come up with a definitive answer.

What He Did

Researcher Robert Morton wasn’t satisfied with the results of previous protein studies or even protein meta-studies. There was a lack of agreement because of widely divergent study inclusion criteria. Subjects were different ages, had different training statuses, different protein intakes, sources, and doses.

Some used only trained participants, older people, supplements containing more than just protein, only one source of protein, shorter resistance training time periods, people who were using protein to diet, or old, frail bastards. Women were included in some studies, but not others.

Morton, however, wanted to see how big a part protein intake played for people who lifted weights. He found 49 studies involving 1,863 men and women and compiled the results.

What He Found

The studies included men and women who’d been weight training for between 6 and 52 weeks. Some used protein supplements and some got their protein from whole food. The protein doses varied from 5 to 44 grams per drink or meal.

Morton detected a distinct relationship between total protein intake and fat-free mass (muscle). Moreover, dietary protein supplementation significantly increased one-rep maxes and cross-sectional muscle-fiber area (muscles got bigger).

No real surprises there, but his statistics did show that protein intake beyond 1.62 g/kilogram didn’t result in any further resistance-training related increases in fat-free mass.

“There have been mixed messages sent to clinicians, dieticians, and ultimately practitioners about the efficacy of protein supplementation,” said Morton, in a press release. “This meta-analysis puts that debate to rest… protein intake is critical for muscle health and the recommended dietary allowance of 0.8 grams per kilogram per day is too low.”

What This Means To You

If you’re a lifter, you need more than the RDA, a lot more. But based on Morton’s meta-analysis, taking more than 1.62 grams per kilogram of bodyweight a day probably won’t lead to any additional growth. That 1.62 grams/kilogram, converted to pounds, looks like the following:

  • 110 grams a day for a 150-pound lifter.
  • 147 grams a day for a 200-pound lifter.
  • 166 grams a day for a 225-pound lifter.

Those amounts aren’t as large as the amounts Hoffman and his peers were recommending, but they’re probably still more than you’re currently using and probably almost impossible to get without using a protein powder supplement (on Amazon).

But as specific as this 1.62 grams/kilogram top-end protein requirement is, there are probably plenty of “outliers” among us who would gain even more mass with even larger amounts of protein. Not everyone fits into a neat, tidy little protein window.




  1. Brooks Kubik, “Did Hi-Proteen Kill Bob Hoffman?”, Dinosaur Training.
  2. Robert W. Morton, et al. “A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults,” British Journal of Sports Medicine, 2017, July 11th.