Here's an uncomfortable truth: the protein recommendation most lifters swear by is based on a meta-analysis that wasn't even statistically significant. The famous 2017 Morton et al. paper, cited over 1,200 times and responsible for the "1.6 grams per kilogram is the ceiling" dogma, had a breakpoint finding that didn't clear the bar for significance. Yet it became gospel anyway. Nearly a decade later, the data tells a very different story, and it's about time the fitness industry caught up.
Why the 2017 Protein Study Got It Wrong
What the Original Research Actually Found
The 2017 Morton analysis pooled existing studies and ran a breakpoint analysis to find the point where extra protein stopped building extra muscle. The number that came out—1.6g/kg, about 0.73g/lb—got treated like scripture. For context, that's roughly 153 grams of protein for a 210-pound person. For most lifters chasing serious hypertrophy, that's low.
Two problems undermined that conclusion:
- The breakpoint itself wasn't statistically significant. The finding that more protein stopped helping past 1.6g/kg was shaky from day one.
- Most underlying studies were done at maintenance or in a surplus, not in a caloric deficit—which, it turns out, matters a lot.
What the Newer Data Shows
Science is supposed to self-correct. In this case it has, just slowly:
So What's the Actual Number?
Forget "1 gram per pound" as some kind of hard ceiling. It's fine as an average for general maintenance. But if you're serious about maximizing hypertrophy—especially while cutting—here's a more accurate target:
- 2.35–3g/kg (roughly 1.05–1.3g/lb)
- Up to 3g/kg (about 1.36g/lb) at the top end
- Most beneficial when lean and in a deficit
- 2.05–2.6g/kg (roughly 0.9–1.2g/lb)
- Adjusted lower to account for differences in lean mass
For a 210-pound man, that upper range means around 286 grams of protein daily. Not a typo. That's a serious jump from the old 210-gram target most people default to.
The Real Trade-Off Nobody Talks About
Here's the catch: calories are fixed. You can't just bolt on more protein without taking something away somewhere else. Fat has a practical minimum for hormonal health, so the trade-off almost always comes out of carbohydrates.
Does Cutting Carbs Hurt Performance?
Surprisingly, not much. At least not if you're a bodybuilder rather than an athlete training for sport-specific performance. A 2024 meta-analysis by Henselmans and colleagues compared low-carb and high-carb groups with protein and calories matched:
The low-carb group just ate more fat to make up the calories.
Daily carb intake isn't the hypertrophy lever people think it is.
The exception: athletes in sports lasting longer than about a minute per effort—running, basketball, soccer—where higher carb intake genuinely boosts performance.
Where Carbs Still Matter: Pre-Workout
Even if total daily carbs don't matter much for muscle growth, pre-workout carbs can still improve what happens in the gym itself. Four mechanisms explain why:
0.2–0.5g/kg of carbs before upper body or lower-volume sessions. 0.5–1g/kg before high-volume lower body days.
How to Actually Hit These New Protein Targets
Getting to 270+ grams of protein daily without feeling like a human chicken breast takes some strategy.
FAQ: Protein Intake and Muscle Growth
Is 1 gram of protein per pound of body weight still a good target?
Why did the 1.6g/kg protein recommendation become so popular if it wasn't statistically significant?
Does protein need increase when cutting?
Do I need a lot of carbs to build muscle?
How many carbs should I eat before a workout?
Is it safe to get a lot of protein from powders instead of whole food?
The Bottom Line
The fitness industry clung to a shaky number for nearly a decade because it was convenient and came from well-known names. That's how these things tend to work. The newer data—more robust, replicated across multiple independent meta-analyses—paints a clearer picture: protein needs are higher than the old consensus suggested, particularly when cutting, and carbs matter far less for muscle growth than most lifters assume.
Next time a cut rolls around, don't just default to the old 1g/lb rule. Bump it toward 1.2g/lb, shift your carbs around the workout window, and build meals around satiating, high-volume foods. The data says it's worth the trade-off.
