In short, not very much. Not very much at all. That’s the short answer. Perhaps 5% of caloric intake at the very most.
But this is NOT the whole story of course.
While many reading this may not be interested in building muscle, it is still a very fascinating topic that provides many insights into how the body works. Most people are more interested in shrinking, not getting bigger (talking about the whole body, not certain parts!). And the funny thing is – that’s when protein really is very useful. Unless of course you want to lose more muscle mass than fat so you can be a marathon runner or runway model or something. Or you want to be a wealthy Manhattan woman for Halloween or something. Then by all means lose weight on a low-calorie raw vegan diet. It’s unparalleled for lean tissue loss. Plus, who wants to be carrying around a huge, heavy brain? It’s a terrible burden (yes, your brain is part of your lean tissue, and it, along with all your vital organs, can shrink from dieting).
There are a lot of myths about protein intake. Most bodybuilding information suggests that protein intake needs to be, at the very least, 1 gram of protein per pound of lean body weight. For me that might be, oh, 170 grams let’s say. Some would recommend TWICE that much!
But I just built more muscle than I ever have in my life and increased my squat and deadlift by 80 pounds each over the last 3 months eating below 100 grams of protein per day on a near vegetarian diet. The trick? Ah, calorie surplus. The most relied upon technique for building muscle.
In a calorie surplus you can’t help but grow new lean tissue. It’s automatic. Even laying around doing nothing, the average person will gain about a ¼ pound of lean tissue for every pound they gain when intentionally overfeeding. Doing some weightlifting ensures even more growth.
The higher the calorie intake, the lower the protein requirements for maintaining muscle mass. 30 grams of protein per day is sufficient for maintaining muscle mass or what is called “nitrogen balance” if you are a normal sized adult male – assuming your calorie intake is quite high. And it doesn’t take much above that level to trigger muscle growth.
Each pound of new muscle contains about 150 grams of protein. Hypothetically, a person could still grow a pound of muscle in 10 days with only 15 grams of protein above what is required to maintain nitrogen balance. And if you are eating, say, 5000+ calories per day like I did from February to the end of April, 45 grams of protein daily equates to only 3.6% of all dietary calories coming from protein. Virtually every food on earth has a higher protein content than that (excluding candy and sweetened drinks). Thus, eating lots of calories ensures adequate protein for muscle growth.
Keep in mind that human breast milk is only about 6% protein. And there is plenty of lean tissue gains on a diet of exclusively mother’s milk at 6% protein.
The average American diet is around 15% protein – on the high end of protein consumption worldwide. Yet bodybuilders throw around all kinds of numbers like 30% protein, 40% protein, and sometimes even higher!
So the answer to the question “How Much Protein Do You Need to Build Muscle?” is not a simple one. There may be lots of people out there giving simple answers – perhaps to keep people from the tiring activity of thinking about it. But the answer is not simple. It depends entirely on the context. So let’s examine a different context…
How much protein do you need to build muscle while you are in a calorie deficit? Ha! Eat as much protein as you like. And even lift as many weights as you like. You are unlikely to see any muscle gains at all. If you do, it will likely last only for a short-time before it comes to a halt. Take calories low enough and you will lose tons of muscle even eating 200+ grams of protein per day and doing even the most well-designed weight training program for growth.
How about eating a more or less “maintenance” level of calories (whatever that is… One guy who follows the site is eating over 8,000 calories per day and his weight is steady – despite doing only small amounts of exercise… Chief is evidently eating “below maintenance calories” with daily 5-plate buffet splurges on his unique high-calorie weight loss program)?
Aha! Alas we have found the reason why bodybuilders eat an absolute crapload of protein! It seems to have almost a dose-response-like impact on one’s ability to grow muscle tissue while at maintenance calories. While it will be slow goin’ in terms of how fast you can build muscle, if you want to build muscle without eating a ton of calories, protein indeed can help. Likewise, in a recent overfeeding study, it was found that those eating the diets with the highest percentage of their calories from protein gained the most lean mass.
So there is some validity to high protein intakes for muscle growth, but calories still trump protein overall when it comes to gaining muscle. And carbohydrates play just as big of a role, if not an even more important role in lean tissue gains – helping protein to be deposited into muscle cells instead of being burned for energy. As Jamie Eason, perhaps the most visible female fitness model on earth if you look at how many magazine covers and advertisements she has been featured in says, “If I want to grow more muscle, I just eat more carbs.” I agree. I had a hell of a time growing muscle on a high-protein diet because my carbs were too low.
No surprises there, as nearly all competitive bodybuilders eat carbs and protein together religiously when trying to put on size.
But I still have one problem with all the high-protein fanaticism when it comes to muscle growth… Protein lowers appetite. It also takes the most calories to digest, so there are many wasted calories on a high-protein diet. Excess protein also seems to have a long-term metabolism-lowering effect (which impairs muscle growth and exercise performance), perhaps due to the previous two factors – perhaps for other reasons (like excesses of tryptophan slowing down metabolic rate).
If calories are the single most important factor in achieving muscle growth, with protein functioning like an added bonus, and protein reduces net calories ingested and reduces appetite – it makes it really hard to eat enough total food to grow muscle if protein intake truly becomes too high – like well above 25% of calorie intake. In other words, I might have fared better overfeeding with more protein, but that is just a hypothetical scenario. No way I could have eaten 5,000 calories per day trying to choke down egg whites, tuna, skim milk, protein shakes – or even fattier cuts of beef.
My official stance on muscle growth would thus be… eat the food (ETF). It’s probably a mistake that so many young weight lifters are reaching first for the protein powder and cans of tuna when they first start lifting weights. I made that mistake in my youth as well, and didn’t get very far with my training.
The times when you really should think about prioritizing protein above other macronutrients is when you are doing enough exercise to trigger weight loss, or losing weight because you’re not eating much. At least, this would be wise if you care anything about your ratio of muscle mass to body fat (hopefully you don’t… my life was certainly much better before I ever thought about such a thing!).
Currently I’m doing some weightlifting AND I’m hiking quite a bit – maybe 30 miles a week. And my history with hiking shows me that strength and muscle mass decrease significantly with this amount of hiking unless you eat a ton of protein or do resistance exercise with it. I’m doing both. I want to protect this strength and muscle I put on. With any interest in toning up muscles and keeping them strong, eating a low-protein diet or relying exclusively on endurance exercise for weight loss is a great way to worsen your body composition long-term – especially knowing that your chances of rebound weight gain are thought to coincide with the amount of muscle mass you lose while dropping weight.
Of course, I don’t recommend or advocate “intentional weight loss” aside from increasing physical activity, sleeping more, de-stressing, and eating more nutritious, less stimulating foods for that very reason (rebound weight gain, but with more fat and less muscle and a lower metabolism than you had before you started). But whether your weight loss is intentional or not, this probably is the time to prioritize your protein intake – an almost universal practice amongst those who have lost significant amounts of weight without gaining it back within 5 years time. But only while you are losing weight. Beyond that I don’t encourage overconsumption of protein. Protein does stimulate the sympathetic nervous system, and I don’t think doing that in excess is desirable. Unless you like bone loss and freezing cold hands and toes and hypothyroidism.