Protein is a major component of muscle building -- without enough of the stuff, it won't much matter how many times a week you hit the weight room.
But between the preachy guys at the gym, message board posts with a suspicious lack of sources, and a glut of anecdotal evidence everywhere you turn, it's easy to get lost in fitness pseudo-science. So we did the research for you to separate fact from fiction. Here are the oft-heard claims, broken down.
1. You can only absorb a certain amount of protein at a time, so multiple smaller meals are better than one big one.
Kind of, anyway. Absorption is about the protein making its way into the bloodstream, which is going to happen regardless of how much you eat. Protein utilization is what this more closely refers to -- how much the body can use for muscle building before it becomes excessive and is burned for energy instead -- which there isn't a perfectly clear answer to. Judging by relevant studies, though, it's likely that the maximum beneficial dose of protein at a meal (if it exists at all) is higher than you'd ever hit from even the biggest steak dinner.
So, basically: don't worry about it. Focus on getting enough protein per day rather than concerning yourself with the amount per sitting.
Norton LE, Layman DK. Leucine regulates translation initiation of protein synthesis in skeletal muscle after exercise. J Nutr, 2006 Feb;136(2):533S-537S.
Crozier SJ, Kimball SR, Emmert SW, Anthony JC, and Jefferson LS. Oral Leucine Administration Stimulates Protein Synthesis in Rat Skeletal Muscle. J. Nutr, 135:376-382, March 2005
2. Eating more protein helps with weight loss.
It's not just for bodybuilding types -- eating a higher protein diet can also be plenty helpful for a fat loss strategy. Based on controlled experiments, subjects eating higher amounts of protein displayed significantly greater fat loss than a control group, while also retaining lean muscle mass.
It's not a magic bullet, obviously; downing a protein shake every day isn't going to cancel out an otherwise poor diet and lacking gym routine. But it'll certainly help if you're putting in the work.
Treyzon, Leo, Steve Chen, Kurt Hong, Eric Yan, Catherine L. Carpenter, Gail Thames, Susan Bowerman, He-Jing Wang, Robert Elashoff, and Zhaoping Li. "A Controlled Trial of Protein Enrichment of Meal Replacements for Weight Reduction with Retention of Lean Body Mass." Nutrition Journal 7.1 (2008): 23.
3. You need to eat at least 1g per lb of bodyweight to build muscle.
This one is tricky, since for every study saying one thing, there seems to be another contradicting it -- and on top of that, every muscle head seems to have his or her own anecdotal evidence of what works for them. What we've found, though, is that while this may be a widespread rule of thumb for weightlifters, it's overly simple and almost certainly overkill.
While extra protein is helpful for building muscle, it's not the be-all-end-all necessity that many people make it out to be. For optimal muscle growth in a serious gymgoer, a daily intake of about .7 g/lb is a good target.
Lemon, Peter W. R. "Beyond the Zone: Protein Needs of Active Individuals." Journal of the American College of Nutrition 19.5 (2000): 513-21. JACN. Web. 21 June 2013.
Phillips, Stuart M. "Protein Requirements and Supplementation in Strength Sports." Nutrition 20.7-8 (2004): 689-95.
4. All proteins work differently, so you've got to buy several different kinds.
Well, kind of. Different types of protein are utilized in slightly different ways, but that doesn't mean you need to spend your entire paycheck at Vitamin Shoppe. Instead, you can tailor your protein of choice to how you're going to be using it.
Casein, for example, is derived from milk just like whey but takes longer to digest. This can be either an advantage or disadvantage, depending on how quickly you're trying to deliver protein to your system -- a slower utilization may be good at keeping you full throughout the entire afternoon so you don't grab a candy bar at 3 pm, or overnight so you don't wake up starving.
But when you drink your shake and the specific utilization time of the type of protein are both a whole lot less important than making sure you're getting enough protein in general.
Hoffman, Jay R., and Michael J. Flavo. "Protein -- Which Is Best?" Journal of Sports Science and Medicine 3 (2004): 118-30. Web. 21 June 2013.
Now you can put that protein powder to good use -- just don't forget to actually put time in at the gym now that you've got it all figured out.