The Million-Dollar Question
"How much protein do I need?" It's the most common nutrition question in fitness. Ask ten people and you'll get ten different answers: 1 gram per pound, 0.8 grams, 2 grams, whatever you feel like.
A major meta-analysis finally provided a data-driven answer.
What the Research Found
Researchers analyzed 49 studies involving 1,863 participants. All studies combined resistance training with varying levels of protein intake, then measured changes in muscle mass and strength.
Key findings:
- Protein supplementation produced significantly greater muscle mass gains
- The benefit plateaued at approximately 1.62g protein per kg bodyweight per day
- Beyond this point, additional protein did not increase muscle gains
- To account for individual variation, the researchers suggested an upper target of 2.2g/kg/day
Translating to Real Numbers
Here's what these recommendations look like for different body weights:
| Body Weight | Optimal Range (1.6-2.2g/kg) |
|---|---|
| 150 lbs (68 kg) | 109-150g protein/day |
| 180 lbs (82 kg) | 131-180g protein/day |
| 200 lbs (91 kg) | 146-200g protein/day |
| 220 lbs (100 kg) | 160-220g protein/day |
Why the Range?
The 1.6-2.2g/kg range accounts for individual variation. Some people may maximize muscle growth at the lower end, while others benefit from the higher end. Factors that might push you toward higher intake include:
- Caloric deficit: When cutting, higher protein helps preserve muscle
- Higher training volume: More muscle damage may require more protein for repair
- Older age: Anabolic resistance means older adults may need more protein per meal
- Plant-based diet: Lower leucine content may warrant higher total intake
The "1 Gram Per Pound" Rule
The popular "1 gram of protein per pound of body weight" rule (2.2g/kg) falls at the upper end of the research-supported range. It's not harmful, but it may be more than necessary for most people.
That said, it's a simple rule that ensures you're covered. If you're not interested in optimizing to the gram, eating 1g per pound is a safe, effective approach.
Does More Protein Mean More Muscle?
Beyond approximately 1.6g/kg, additional protein does not produce additional muscle growth. Your body can only synthesize muscle tissue so fast, and excess protein is simply oxidized for energy or converted to other compounds.
This doesn't mean high protein is harmful. It just means the extra chicken breast isn't contributing to extra muscle. It's contributing to your energy needs, same as carbs or fat would.
Protein Timing and Distribution
While total daily protein matters most, distribution can optimize results:
Per-meal dose: Aim for 0.4-0.5g/kg per meal (25-40g for most people) to maximize muscle protein synthesis at each feeding.
Meal frequency: 3-5 protein-rich meals spread throughout the day is likely optimal. Each meal triggers a protein synthesis response.
Post-workout: Consuming protein within a few hours of training takes advantage of increased muscle sensitivity. But the "anabolic window" is much longer than previously thought.
Protein Quality Matters
Not all proteins are equal. For muscle building, prioritize:
Complete proteins: Contain all essential amino acids. Animal sources (meat, fish, eggs, dairy) and soy are complete. Most plant proteins need to be combined.
Leucine content: Leucine triggers muscle protein synthesis. Aim for 2-3g leucine per meal. Whey protein is particularly high in leucine.
Digestibility: Some proteins are more bioavailable than others. Animal proteins typically score higher than plant proteins on digestibility metrics.
Practical Strategies to Hit Your Target
Getting adequate protein requires planning. Here's how to hit your numbers:
1. Protein at every meal: Don't save all your protein for dinner. Include 30-40g at breakfast, lunch, and dinner.
2. Protein-first meal planning: Plan your protein source first, then add carbs and fats around it.
3. Track for a week: Most people overestimate their protein intake. Track everything for one week to calibrate your perception.
4. Strategic supplementation: Protein powder isn't magic, but it's convenient. A shake can bridge gaps when whole food isn't practical.
5. Prep protein in advance: Grilled chicken, hard-boiled eggs, and Greek yogurt are grab-and-go options that make hitting targets easier.
The Bottom Line
The research is clear: for maximal muscle growth, consume 1.6-2.2g of protein per kg of body weight daily. Below this range, you're likely leaving gains on the table. Above this range, you're not gaining extra muscle benefit.
Distribute protein across 3-5 meals, prioritize complete proteins with adequate leucine, and be consistent. Protein intake isn't complicated, but it does require intentionality.
Reference
Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376-384. PMID: 28698222