This is Part 1 of a 3-part series on building muscle and strength with protein. Before getting started, you might want to go back and read the Introduction here.
[Part 1] How Much Protein Is Optimal?
Strength athletes need more protein than average folks not only to achieve their training goals, but also simply to stay healthy. You knew that already. What's less clear (and the subject of ongoing debate, even among researchers) is how much protein is optimal for weight training athletes whose goals are to gain lean muscle and strength.
As promised, I'm going to give specific guidelines later in this post. Before we get to it, though, let's quickly review the list of benefits from a high-protein diet:
Fat loss -- Diets higher in protein promote greater fat loss for the following reasons:
- Protein produces feelings of satiety (fullness), acting as a natural appetite suppressant. Other things constant, a reduced appetite means less eating and fewer calories consumed over time.
- Protein is very unlikely to convert to body fat, given the remote likelihood of amino acids (the product of protein digestion) converting to fatty acids in the liver, even in overfeeding situations of 1,000 excess calories/day. [Bray GA et. al. 2012]
- Protein digestion burns more calories than the digestion of carbohydrates or fats, and leads to a greater increase in metabolic rate due to its higher thermic effect.
Muscle gain -- Higher-protein diets, due to the supply of amino acids from protein digestion, lead to greater increases in lean body mass via the following:
- More protein synthesis. You see, under ordinary circumstances, skeletal muscle protein regularly "turns over" (that is, synthesizes and degrades) according to an equal balance that results in zero net gain or loss over time. (This process, which occurs in other cells throughout the body, such as in brain cells, for example, is required to prevent the accumulation of damaged proteins and the interference of normal biological functioning.) However, weight training skews the balance of turnover in favor of synthesis (making more protein than is being broken down), leading to a net increase in muscle protein and, therefore, muscle cell size. But there's a key caveat to this: You must be supplying your body with enough amino acids (from ingested protein) to produce (synthesize) the new muscle. Without this, your efforts in the gym are futile!
- Less protein degradation (breakdown). This is the flip side of the above equation. Since amino acids from protein are not only essential for building muscle, they're also used to fuel a wide array of biological processes throughout the body, creating a big demand. If amino acids aren't supplied sufficiently through your diet, then your body will break down or "catabolize" your muscle tissue in order to source the amino acids needed for those other functions! But by ingesting enough protein (especially of the right types and at the right times), you can ensure a steady supply of amino acids to meet all demands and preserve your muscle, even during periods of calorie restriction. In fact, with the right strategy, you can even reduce protein degradation to a level that produces muscle gain by again tipping the scale in favor of synthesis.
OK, so the question that started this ... How much protein is required to maximize muscle growth?
There is good and bad news here, and since I always like to save the best for last, I'm going to deliver the bad news first.
The bad news is that the answer is nuanced, meaning that there is no single rule of thumb to follow. Protein demands vary widely depending on the subject and one's lifestyle. (E.g. genetics, gender, age, activity level and type, etc.)
The good news is that a plethora of anecdotal evidence and a fair bit of scientific study provide a pretty solid basis for determining protein requirements for weight training athletes whose goals include maximizing lean body (or "fat-free") mass.
The guidelines I will present below are based on scientific research that have considered the safety concerns surrounding high-protein diets (centering on the rate at which the gastrointestinal (GI) tract can absorb amino acids from dietary proteins, and the liver's capacity to metabolize proteins and excrete excess nitrogen if intake is too high).
For Athletes Under "Normal" Dietary Conditions
By "normal," I mean athletes who are not restricting calories through traditional dieting.
As you'll see below, protein requirements increase when total daily calories are restricted to below-maintenance levels. For these "normal" athletes, a solid rule of thumb to follow is approx. 2 - 2.5 grams of protein per kilogram of body weight, per day, which equates to roughly 1 gram of protein per pound.
Thus, a 200 LB. bodybuilder (who is not "cutting") would shoot for 200 grams of protein per day. [Bilsborough et. al. 2006]
For Athletes Who Are Restricting Calorie Intake
Dieting presents special protein needs.
As calorie deficits (i.e. total calories ingested minus total calories required to maintain your present body weight) rise, more protein is required to preserve your lean body mass and support physical performance. In fact, substantially more.
For dieting athletes, a better rule of thumb is to consume up to approx. 3 grams of protein per kilogram of fat-free mass, per day, or roughly 1.5 grams of protein per pound of fat-free mass. [Helms, et. al. 2013]
Notice that I said fat-free mass, not total body weight, as for non-dieting folks.
What is fat-free mass?
It's your body weight minus the weight of your body fat. In other words, it's dropping your body fat from the calculation, since protein demands are more closely correlated with lean mass than with total mass, and dieting athletes need to be more precise in estimating their protein requirements.
So, for example (using the 200 LB. bodybuilder referenced above):
A 200 LB. bodybuilder with 15% body fat would estimate his daily protein requirement as follows:
- First, determine fat-free mass: 200 x (1-.15) = 170 (lbs. of fat-free mass), where 200 is body weight in pounds and .15 is % body fat expressed as a decimal.
- Multiply fat-free mass by 1.5: 170 x 1.5 = 255 (grams of protein to consume per day)
Notice the 55 grams/day increase in the same 200-LB. bodybuilder's protein requirement when dieting...
This is especially remarkable when you consider that he's consuming less total calories, so his percentage calories from protein rise very significantly.
Next: Breaking Down The Numbers
OK, so now you have a couple rules of thumb to implement when planning your daily protein intake. But that's just the start...
Now you need to figure out how, and when, to consume it.
One way is to eat lots of whole foods, and many people do this (or try to). The thing is, it means eating a ton of meat, and although I love a steak as much as anyone, I haven't, in 20 years, figured out how to eat 200 grams of protein per day without spending an inordinate amount of time in the kitchen and shunning a full-time job.
(Sure, you could front- or back-load the protein by having a giant breakfast or dinner, but a key part of nutrient absorption is timing, and trying to force-down 100 - 200 grams of protein in 1 or 2 meals is far from ideal in that regard. In the end, if you're not adequately digesting the protein for amino acid absorption, it doesn't matter how much you're swallowing.)
Enter protein supplementation.
Protein supplements comprise a huge industry, and for good reason.
While it's very difficult to consume 200 grams per day of quality proteins from whole foods, it's very easy to do so with protein supplementation, which can provide excellent protein "pulses" between meals, enabling you to take in your requisite protein for the day as well as providing a steady supply of amino acids to minimize protein catabolism, as alluded to above.
To the latter point (getting an anti-catabolic effect from protein supplementation), not all proteins are created equal in that regard. Some protein types are better for rapid absorption, and others for slow absorption, releasing amino acids steadily over a period of several hours.
Given that, which protein supplements are the best for meeting your day-to-day protein needs with precision?
This is a key question...
Stay tuned for PART 2 (of 3) in this blog series, in which I reveal the protein supplements that work the best as your core protein source.
Until next time,