Does eating more protein result in more gains in strength or muscle size?

 Q: Is it really necessary to increase one’s protein intake above the 0.8 grams per kilo of bodyweight recommended by most health care professionals? I’ve heard that eating more protein does not always result in more gains in strength or muscle size.

A: You’re looking at the numbers—let’s look at the research. An upcoming review in the Journal of the International Society of Sports Nutrition identifies the dose of protein that is necessary to produce dramatic increases in muscle and strength from resistance training—and the dose is higher than is commonly thought.

Researchers analyzed a wide range of previous studies that compared strength gains and body composition changes when participants took various types of supplemental protein in conjunction with training. They found that in studies that tested the effect of multiple protein intakes on strength and muscle gains, a higher daily protein intake was always more effective. In studies that produced what they term a “protein spread” effect, an average of 66 percent greater protein intake led to statistically significant strength and body composition gains. In contrast, there were no muscular or strength benefits in studies in which participants increased their protein by only 10 percent over the control groups.

For example, in a 12-week study in which college football players ate either two grams per kilogram of bodyweight per day or 1.24 grams per kilogram per day, the increase in maximum squat strength was 14.3 kilograms greater in the group that got the higher dose.

A second study put participants who resistance-trained into three groups and had them supplement with various amounts of protein: three grams per kilogram of bodyweight per day of whey protein, three grams per kilogram of soy protein or 1.7 grams per kilogram per day of protein for the control group. The results showed that the whey group gained 2.5 kilograms of muscle, the soy group gained 1.7 kilograms of muscle and the control group gained 0.3 kilogram, highlighting the superiority of a large dose of whey on muscle development. Note that this study confirms that soy is an inferior form of protein.

Finally, a study that compared 3.3 grams per kilogram of whey protein per day with a 1.2 grams per kilogram per day control group showed that higher protein intake brought muscle gains of 2.3 kilograms as well as greater strength, while the control group gained less than a kilo of muscle and no strength.

The researchers also identified a “protein change” theory. The greatest increases in strength and muscle size were seen in participants who increased their protein by 60 percent over what they normally ate. Participants who increased their usual protein by only 6 percent made no gains in muscle or strength. In contrast, those who showed impressive gains in muscle size increased their protein by 97 percent over baseline!

All the research adds up to this takeaway point: To achieve the greatest increases in strength and muscle size from training, you need more than two grams of protein per kilogram of bodyweight per day. Specifically, 2.38 grams per kilogram reliably produced muscular and strength gains in the studies reviewed. A higher or variable dose may be more effective, depending on individual training goals.

Editor’s note: Charles Poliquin is recognized as one of the world’s most suc-cessful strength coaches, having coached Olympic med-alists in 12 different sports, including the U.S. women’s track-and-field team for the 2000 Olympics. He’s spent years researching European journals (he’s fluent in English, French and German) and speaking with other coaches and scientists in his quest to optimize training methods. For more on his books, seminars and methods, visit www.CharlesPoliquin.com. Also, see his ad on the opposite page .   IM