Most bodybuilders try to eat about 1 gram of protein per pound of body weight per day. Muscle is made out of protein, they say. If you want to maximize your rate of muscle growth, you need to eat plenty of protein.
Do you really need to eat that much protein? What happens if you don’t?
Most research shows you can maximize your rate of muscle growth with as little as 0.7 grams of protein per pound of body weight per day (1.5g/kg/day). That isn’t a recommendation, though; it’s the minimum amount the average person needs to build muscle at full speed (meta-analysis).
If you want to eat even more protein, that’s perfectly fine. In fact, if building muscle is really important to you, it might make sense to intentionally overshoot the minimum target. After all, some people do great with less protein, whereas other guys can benefit from more.
You could easily imagine someone who’s more muscular and active than average benefitting from extra protein. You also imagine someone with poor muscle-building genetics needing more protein to get good results.
Plus, even if you track your calories, you can’t know exactly how much protein you’re eating. Nutrition labels aren’t perfectly accurate. Neither are people. Not even me.
How Much Protein Do You Need When Bulking?
When you’re bulking, you’re consuming an abundance of calories. Protein is important, but your body has plenty of nutrients floating around, and those nutrients can be used for a variety of different things. If you’re eating plenty of carbs and fat, your body can use them for energy, reserving the protein for muscle growth.
There’s no need to eat extra protein while bulking. You can stick with the usual target of eating at least 0.7–1g of protein per pound per day.
How Much Protein Do You Need When Cutting?
When you cut, you’re consuming fewer calories than you need. Some of the protein you eat might be used as energy instead of being sent to your muscles.If your body needs more protein for your bones, nails, hair, and hormones, it might break down your muscles to get it.
It pays to eat extra protein when cutting. 1 gram per pound of body weight per day is a good minimum target (study). I realize that’s hard. You’re being asked to eat far more protein per calorie. That can mean more protein powder, more chicken breasts, more skim milk, and fewer moments of happiness. Such is the desolation that is cutting.
What Happens If You Don’t Eat Enough Protein?
If you don’t eat enough protein, you’ll probably build muscle at a proportionally slower pace (full explanation). For example, if 100 grams is enough to maximize your rate of muscle growth, but you only eat 70 grams, then you’d build muscle 30% slower.
If you aren’t eating enough protein while cutting, the downside is more dramatic. Your body will break down your muscles to get the protein it needs. You might be able to prevent that muscle loss by keeping your calorie deficit more modest and losing weight more slowly.
What We Recommend
I’ve gained 70 pounds so far. I ate more than 1 gram of protein per pound per day while gaining my first 50 pounds. I ate closer to 0.7 grams per pound while gaining my final 20 pounds. I didn’t notice a difference in the results I got.
However, people come to us because they care about building muscle. We need to make sure they get great results. So we recommend eating a full gram per pound, just to play it safe—just to make sure. But we also make it clear that eating 0.7 grams per pound should be just as good.
As far as priorities go, I think it’s far more important to eat enough calories and to get those calories from balanced meals. If you eat a few meals per day, and if all of those meals have a source of protein in them, you’ll build muscle like a demon.
Conclusion
If you’re happy making gradual progress, you can probably get away with eating less protein. You’ll still gain muscle and strength; you’ll just gain it more slowly. You can still reach your genetic muscular potential; it will just take longer.
If you’re eager to build muscle as quickly as possible, it pays to eat enough protein. You may even want to build in a margin of error. That’s what most bodybuilders do. They eat about 30–40% more protein than they need, ensuring it’s never a limiting factor.
Shane Duquette is the co-founder of Outlift, Bony to Beastly, and Bony to Bombshell. He's a certified conditioning coach with a degree in design from York University in Toronto, Canada. He's personally gained 70 pounds and has over a decade of experience helping over 10,000 skinny people bulk up.
Marco Walker-Ng is the co-founder and strength coach of Outlift, Bony to Beastly, and Bony to Bombshell, and is a certified trainer (PTS) with a Bachelor's degree in Health Sciences (BHSc) from the University of Ottawa. His specialty is helping people build muscle to improve their strength and general health, with clients including college, professional, and Olympic athletes.
