As a personal trainer and nutritionist, I'm often asked about protein and how it relates to health and fitness:
This post is part one of two that will clear up confusion about the current information on protein consumption as well as provide research for your consideration. Part two will cover good sources of protein as well as some information regarding protein shakes.
"The RDA (recommended daily allowance) on a food label says 50-60g, but I’ve heard of bodybuilders taking in more than 2g per pound. Which is it?"
As with most things health-related, the answer is going to be somewhere in the middle. The minimum amount of protein needed to maintain a positive nitrogen balance is around 0.8g/kg of bodyweight or .36g/lb. Your body is always building and breaking down tissue, and all muscle and organ tissue is made of protein. Therefore to maintain your base amounts of tissue, this amount would probably suffice to ensure you are not malnourished. This is the number used on food labels, and the RDA that we have seen on all our food is based on a 2000 calorie per day diet. It also recommends we consume nearly all of our calories from carbs (remember that food pyramid suggesting 6-11 servings of grain per day?) and has not changed since 1968.
"That seems pretty low, how come the fitness industry has been pushing protein so much lately?"
Research has come a long way since then, and for active individuals in general, there is much data out there suggesting a higher amount of protein is needed. The consensus falls between 1.4-2.0g/kg per day, or 0.63-0.91g/lb per day. There is still a decent sized range here for a few reasons:
Another factor that influences where you fall in this range is whether or not you are in a calorie surplus or calorie deficit. Contrary to what most people think, you really need more protein when you are dieting, at least if you want to maintain your muscle mass and lose mostly fat, simply because protein requires more energy to maintain than fat does, and training breaks the body down, while eating fuels it back up. If you're getting broken down in training and losing weight, your body won’t spare the muscle tissue since it “costs” more to maintain.
"Okay, that's all good but it doesn't fully answer the question. My trainer tells me to have one gram per pound of body weight? Isn’t that above that range? I heard too much protein can be unsafe, is this true?"
There is no evidence that consuming more than this recommended amount of protein is harmful in healthy individuals, only that this range is optimal for maximizing performance. One myth is that too much protein is bad for your kidneys, but this was partially based off of a high protein diet giving similar biomarkers as to those with kidney failure. This does not mean increasing protein intake causes kidney failure. Another myth is that it is bad for your bones, as high protein diets can increase urinary excretion of calcium. This is a very simplified look at the issue, and the science actually points to low protein diets being correlated with bone issues.
I know many of you read this blog for food information so that’s enough on the science. If you’re interested in learning more, check out this article which contains a plethora of linked research.
As a trainer, I still often suggest one gram per pound of protein target to my clients for several more practical reasons than all of this:
Stay tuned for the conclusion of this article next month, and please do not hesitate to add a comment with any questions you have or any more information you’d like to see in part 2.
If you'd like help learning how to perfectly cook protein, The Chopping Block offers several hands-on cooking classes to get you comfortable cooking whatever variety of protein you prefer: