Eat a high-protein diet to gain muscle and strength fast. A new review in the Journal of the International Society of Sports Nutrition identified 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 all 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, and there was what they called a “protein spread” effect. They found there was an average of 66 percent greater protein intake in studies that showed statistically significant strength and body composition gains. In contrast, studies that produced no muscular or strength benefits only had a 10 percent greater dose of protein than controls.
For example, in a study that had college football players consume either 2 or 1.24 g/kg/day of protein over 12 weeks, the group that consumed the higher 2 g/kg dose gained 14.3 kg greater increase in maximum squat strength.
A second study had participants resistance train and supplement with either 3 g/kg/d of whey protein, the same dose of soy protein, or 1.7 g/kg/d protein intake in a control group. Results showed that the whey group gained 2.5 kg of muscle, the soy group gained 1.7 kg of muscle, and a control group gained 0.3 kg, highlighting the superiority of a large dose of whey on muscle development.
Finally, a study that compared 3.3 g/kg/d of whey protein with a 1.2 g/kg/d control group showed that higher protein intake resulted in muscle gains of 2.3 kg and as well as greater strength, while the control group gained less than a kilo of muscle and no strength.
Researchers also identified a “protein change” theory. The most strength and muscle size was gained from studies that had participants increase their protein intake for the study by 60 percent over what they normally consumed. Studies that didn’t show muscle or strength gains only increased habitual protein intake by 6 percent. For example, two studies that showed impressive muscle size gains increased protein intake by 97 percent over baseline!
To achieve the greatest increases in strength and muscle size from training and protein, take away the following points:
• Shoot for more than 2 g/kg/d of protein—researchers suggest 2.38 g/kg/d is the dose that reliably produced muscular and strength gains in the studies reviewed. A higher or variable dose may be most effective depending on individual training goals.
• The 2.38 g/kg/d is much higher than the amount of protein commonly recommended by nutrition professionals. Researchers note that this review shows the evidence robustly supports the higher protein intake.
• Whey protein appears to be superior to other protein sources.
• Previous studies indicate best results will come from getting a large portion of protein from high-quality food sources and supplementing to reach the daily intake goal.
• It may be beneficial to vary protein intake based on the evidence that a large change in protein intake can produce significant strength and size gains. However, the “protein change” theory is based off the fact that baseline protein intake was always fairly low—below 1.5 g/kg/d. Therefore, it may be most effective to consistently eat a higher dose above 2 g/kg/d.
• Studies show that when increased protein intake is combined with intense strength training, it can produce significant fat loss. One study compared a 2.3 g/kg/d protein intake with 1.45 g/kg/d and showed that the higher protein group had 5 percent less body fat by the end of the 10-week study, despite the fact that they consumed 400 more calories a day than the lower protein group.
Bosse, J., Dixon, B. Dietary Protein To Maximize Resistance Training: A Review and Examination of Protein Spread and Change Theories. Journal of the International Society of Sports Nutrition. 2012. Published Ahead of Print.