How Much Protein Do You Need Per Meal?

What’s the magic number? Twenty grams? Forty grams? How much protein should you get per meal? The dirty little answer to that is, we honestly don’t know. Not yet anyway.

Clearly, your bodyweight and training goals will affect what your feeding strategy should be. A 400-pound sumo wrestler obviously has greater macronutrient needs than a 100-pound ballet dancer.

A group of scientists recently examined the effect of one of my favorite protein foods—beef. We’ve seen the data on whey, casein, soy and even egg protein. It’s about time we got to the meat of the matter, no pun intended. The researchers examined the dose-response of muscle protein synthesis, with and without weight-training exercises, to graded servings of beef. Thirty-five middle-aged men, average age 59, ate either 0 grams, 57 grams (two ounces, 12 grams of protein), 113 grams (four ounces, 24 grams of protein), or 170 grams (six ounces, 36 grams protein) of ground beef—15 percent fat. They then performed a bout of unilateral resistance exercise to allow measurement of the fed state and the fed-plus-resistance-exercise state for each serving.

Without getting into the complex biochemistry involved, the researchers determined how each amount of beef protein affected muscle protein synthesis. They discovered that protein synthesis was increased with the 170-gram serving of beef—six ounces—to a greater extent than all other doses at rest and after resistance exercise. Furthermore, an isolated bout of weight-training exercise was potent in stimulating muscle protein synthesis and acted additively with feeding.¹

So what does the study tell us? First of all, it confirms other studies showing that getting a protein meal after training is good for encouraging muscle protein gains. Second, it tells us that at least in middle-aged men, muscle protein synthesis keeps rising even at the 36-gram dose.

Many have theorized that all we need is a mere 20 grams of protein per meal to maximize protein synthesis. Clearly, that isn’t the case. Though it would be interesting to see what happens in the younger generation, the 18-to-40-year-olds.

On the flip side, it would be intriguing to see if beef protein supplementation had a different effect from, say, whey and casein supplementation postworkout. Once you reach a certain protein consumption level—for example,  40 grams per meal—does it matter if the protein comes from whey, casein, egg or beef? Or even soy?

I would surmise that at lower protein-consumption levels, like a protein-bar snack of 20 grams, the quality of the protein may be more critical. But at higher levels, like 40 grams, it may not matter all that much—assuming your primary goal is triggering muscle protein gain.

The bottom line: I’d suggest getting 40 grams of protein postworkout if your goal is to maximize muscle protein synthesis.

—Jose Antonio, Ph.D.

 

Editor’s note: Jose Antonio, Ph.D., is an assistant professor at Nova Southeastern University in sunny South Florida.

 

¹ Robinson, M.J. et al. (2013). Dose-dependent responses of myofibrillar protein synthesis with beef ingestion are enhanced with resistance exercise in middle-aged men. Applied Physiology, Nutrition, and Metabolism (Physiologie Appliquee, Nutrition et Metabolisme). 38:120-125. doi:10.1139/apnm-2012-0092.