Most gym-goers are eating more protein than they'll ever need — and the supplement industry is perfectly happy about that. The idea that you need to slam 300g of protein a day to build muscle is one of the most persistent myths in fitness, and it's costing people money, digestion, and unnecessary food stress.

Here's the reality: a landmark 2018 meta-analysis covering 105 randomized controlled trials found that muscle protein synthesis essentially plateaus once you hit around 1.62g of protein per kilogram of bodyweight (about 0.73g per pound). Beyond that point, more protein doesn't build more muscle.

What the Research Actually Says

The Morton et al. 2018 study published in the British Journal of Sports Medicine is the most comprehensive analysis of protein and muscle growth ever conducted. Researchers pooled data from 1,800 participants across 105 RCTs. The takeaway: the upper limit where protein intake stops making a meaningful difference to muscle gain sits at 1.62g/kg/day, with a confidence interval that stretches to 2.2g/kg in some subgroups.

That's not a number to hit exactly — it's a ceiling. Most people building muscle seriously can do it effectively anywhere between 1.4–2.0g/kg (roughly 0.6–0.9g per pound).

The International Society of Sports Nutrition (ISSN) position stand on protein echoes this, recommending 1.4–2.0g/kg/day for exercising individuals. For those in a caloric deficit or who are more advanced trainees, staying toward the higher end of that range makes sense to preserve muscle mass.

Why the "1g Per Pound" Rule Exists

The 1g per pound rule (2.2g/kg) became gym gospel for a few reasons. First, it's a round number that's easy to remember and track. Second, it has a margin of safety built in — if the plateau is around 0.73g/lb, then 1g/lb ensures you're definitely above it. Third, supplement companies have a financial interest in you consuming more protein.

Is following the 1g/lb rule harmful? For most healthy people, no. Extra protein gets oxidized for energy; it doesn't magically convert to muscle. But if eating that much protein makes it harder to stick to your diet, or crowds out carbohydrates you need for performance, then it's working against you.

The practical takeaway: 0.7–1.0g per pound of bodyweight is a completely defensible target range. Lean toward 1g/lb if you're in a caloric deficit or have a lot of training volume. Lean toward 0.7–0.8g/lb if you're in a surplus and eating is already a challenge.

Protein Targets by Bodyweight

Use this table to find your daily protein target. The three columns represent the Minimum (0.7g/lb), Optimal (1.0g/lb), and High End (1.2g/lb) of the evidence-based range.

Bodyweight	Minimum (0.7g/lb)	Optimal (1.0g/lb)	High End (1.2g/lb)
140 lbs	98g	140g	168g
160 lbs	112g	160g	192g
180 lbs	126g	180g	216g
200 lbs	140g	200g	240g
220 lbs	154g	220g	264g

If you're somewhere in between those bodyweights, just multiply your weight in pounds by 0.7, 1.0, or 1.2 to get your personal range. Most people doing consistent resistance training land somewhere between Minimum and Optimal — reserve the High End for cutting phases or high training volume.

Does Protein Quality Matter?

Yes — but probably less than you think if you're eating a reasonably varied diet. Complete proteins (animal sources and some plant sources like soy and quinoa) provide all nine essential amino acids your muscles need for repair and growth. Leucine in particular is the key amino acid that triggers muscle protein synthesis, which is why leucine-rich sources like whey, chicken, and eggs are often recommended post-workout.

If you're eating mostly plant-based protein, you'll want to aim toward the higher end of the range — around 1.8–2.2g/kg — to account for lower digestibility and leucine content in most plant proteins. Combining complementary proteins (rice and beans, for example) throughout the day takes care of the amino acid profile issue without needing to overthink each meal.

When Higher Protein Matters Most

There are specific scenarios where pushing toward or slightly above 2.0g/kg makes practical sense:

Cutting phases. When you're in a caloric deficit, your body has a greater tendency to catabolize muscle tissue for energy. Higher protein intake (1.8–2.4g/kg) acts as a protective buffer. Research by Helms et al. shows that natural bodybuilders in a cut benefit from intake on the higher end of this range.

Advanced trainees. As you get more muscular, your body becomes more efficient at recycling amino acids and may benefit from slightly higher intake to continue driving adaptation.

Older adults. Anabolic resistance — the reduced sensitivity to protein's muscle-building signal — increases with age. Research supports higher per-meal doses (at least 40g, rather than the typical 20–30g recommendation for younger adults) to achieve the same MPS response.

Higher training volume. If you're training twice a day or doing significant cardio on top of lifting, protein needs increase to support recovery across multiple sessions.

Practical Tips for Hitting Your Target

The biggest barrier for most people isn't knowing the number — it's consistently hitting it. A few approaches that work:

Anchor each meal around a protein source first, then build the rest of the meal around it. Chicken, eggs, Greek yogurt, cottage cheese, canned fish — these are cheap, convenient, and protein-dense.

Don't rely on protein shakes as your primary source. Whole food protein sources are more satiating and tend to have better overall amino acid profiles. Use shakes to fill gaps, not as a foundation.

Track for two to three weeks when you're first dialing in your intake. Most people are surprised by how off their estimates are — both high and low on different days.

Use the Bulked protein calculator to get your exact daily target based on your bodyweight, goal, and activity level. It takes about 30 seconds and gives you a personalized number instead of a generic rule of thumb.

The Bottom Line

You don't need 300g of protein a day. You don't even need 250g. What you need is a consistent daily intake somewhere between 0.7–1.2g per pound of bodyweight — Minimum for general training, Optimal for active muscle building, High End for cutting phases — spread across multiple meals, coming primarily from high-quality protein sources. The Morton et al. 2018 data is clear: beyond roughly 1.6g/kg, you're not building more muscle — you're just spending more money on protein and asking your kidneys to do more work.

Get the number right, be consistent with it, and put your energy into the things that actually move the needle: progressive overload, quality sleep, and enough total calories to support growth.

Related Guides

Best High-Protein Foods Ranked by Protein Per Calorie — once you know your target, here's how to hit it efficiently
How Much Protein Can Your Body Absorb in One Meal? — structuring your daily protein across meals for maximum muscle protein synthesis
How Much Protein Do Women Need to Build Muscle? — the same evidence applied to women's specific considerations

How Much Protein Do You Actually Need to Build Muscle?