Researchers pooled every controlled trial ever done on this question. The rice was along for the ride.
“Every extra gram of carbs eaten specifically for gains added zero measurable muscle growth. Not in one study. Not in five. In all eleven.”
You've been measuring rice on a kitchen scale for months.
Not because you love rice. Because every training partner, every bodybuilding forum, every macros calculator told you the same thing: carbs build muscle. The chicken is for protein. The broccoli is for micronutrients. And the rice is for gains.
In 2024, three academics wrote a piece in The Conversation arguing that carbs are "as important as protein" for muscle growth. They opened with a Mr. Universe winner's anecdote. That article still ranks on page one.
Then a team of researchers did something nobody else on that search results page had done. They pooled every controlled trial ever conducted on this exact question.
Eleven controlled trials all pointed the same direction: carbs don't independently drive muscle growth. The protein was doing the work. The carbs were a calorie delivery system.
- Researchers pooled every controlled trial on this question and found no measurable effect of carb intake on muscle growth — the result held across all eleven studies.
- Most studies tracked "lean mass" using scans that can't tell the difference between real muscle and stored glycogen plus water — the two that measured actual muscle size found the opposite direction.
- Low-carb groups tended to lose more fat, not because carbs are fattening, but because cutting carbs made people accidentally eat less food.
- The researchers rated their own confidence at two out of four — a small positive effect of carbs hasn't been ruled out, but no lab has detected one yet.
- Carbs help you eat enough calories to support growth, but they don't send a growth signal to your muscles. The carb slider moves freely as long as total food and protein stay sufficient.
What Eleven Labs Found
In February 2026, a team led by Menno Henselmans published the first meta-analysis directly testing whether carbohydrate intake affects muscle growth during resistance training. The study appeared in Sports Medicine and pooled eleven randomized controlled trials — every qualifying study on the question, spanning over a decade of research.
The participants were 227 adults, predominantly trained males aged 18 to 65, who were split into higher-carb and lower-carb groups while keeping protein matched.
The result: carbs made no measurable difference to muscle growth. The pooled effect was too small to register as meaningful and fell well short of what researchers need to call something real.
But the number alone isn't what makes this hit. Every single study pointed the same direction. The disagreement between labs was literally zero.
When the researchers removed one study at a time to test whether any single trial was driving the result, the answer held. When they restricted the analysis to studies that matched calories between groups, the result was identical.
The rice in your meal prep container contributed nothing to your muscle growth. The protein was doing all the work.
Why Everyone Thought They Knew Better
If carbs don't build muscle, why has every coach, every supplement company, and every search result been saying otherwise?
Part of the answer lives in what "muscle growth" actually means when researchers measure it. Nine of the eleven studies tracked "lean mass" or "fat-free mass" using whole-body scans. The problem: those scans can't tell the difference between real muscle tissue and glycogen stored inside that tissue, plus the water that tags along.
One study demonstrated the issue viscerally. After ten weeks on a ketogenic diet, participants reintroduced carbs for a single week. Their "fat-free mass" jumped 4.8% in seven days.
Nobody builds that much real muscle in a week — what happened was glycogen and water flooding back into tissue that had been depleted. The scan recorded it as "lean mass gained."
The two studies that used a different approach — measuring actual muscle thickness with ultrasound, imaging the actual muscle directly — told a different story. When the researchers isolated those two, the direction of the result reversed. The lower-carb groups showed slightly more actual muscle growth.
Two studies is too few to draw a firm conclusion, and the researchers were transparent about that. But the direction flip reveals something the whole-body scans hid. The "advantage" of carbs for muscle growth may have been glycogen and water masquerading as real muscle on a scan.
A typical strength-training session depletes your muscle glycogen by less than half. The threshold where low glycogen actually starts hurting performance is well below what a normal workout touches — your muscles had enough fuel the whole time, whether you ate rice beforehand or not.
What the Scientists Themselves Don't Know Yet
Here is where most coverage of this study would stop. The finding is dramatic enough to carry a headline and move on.
But the researchers rated their own confidence at two out of four — meaning future research could still shift the conclusion.
The reasons are honest. Only eleven studies exist in the entire literature. The average trial enrolled about 20 participants. Every study ran for less than 12 weeks.
Future research could still land anywhere — from carbs hurting a little to helping a little. A world where carbs help a little hasn't been ruled out.
What has been established: across every study ever done, the effect of carbs on muscle growth is either zero or too small for any of the eleven labs to detect. That consistency — not the size of any single study — is the strongest signal in the data.
What Carbs Actually Do
If carbs aren't building muscle, what are they doing on your plate?
The meta-analysis offers a clue in its secondary data. When the researchers analyzed fat mass changes separately, they found a trend toward greater fat loss in the lower-carb groups. The effect fell just short of the threshold for significance, but the direction was consistent: people eating fewer carbs tended to end up leaner.
That pattern lines up with a well-documented phenomenon. Low-carb diets suppress appetite. People on them tend to eat fewer total calories without trying. Several studies in the meta-analysis confirmed exactly this — participants reported similar intakes, but their body composition changes told a different story.
The lead author's own summary strips the finding to a single principle: this is about energy intake, not carbohydrate intake. Carbs don't send a growth signal to your muscles. They make it easy to eat enough food.
Cut carbs too hard on a bulk, and your muscles won't starve for carbs. They'll starve for calories — and that distinction is the entire finding.
“Carbs aren't a muscle-building tool. They're a calorie vehicle. The risk of going low-carb isn't losing gains — it's accidentally eating too little.”
What This Changes
The lead author, Menno Henselmans, isn't working from a disconnected academic office. He's the founder of Bayesian Bodybuilding — one of the most recognized evidence-based fitness coaching brands online — and coaches physique athletes full-time in six languages.
The person behind "Henselmans et al. 2026" in Sports Medicine is the same person answering DMs from lifters about their macros.
His team's eleven controlled trials delivered one clear signal. Carbs are not an independent driver of muscle growth, as long as total calories and protein are sufficient.
That finding doesn't stand alone. A separate systematic review by the same research group examined 49 studies on carbs and strength training performance. The vast majority — including all 16 studies that matched calories — showed no benefit of higher carb intake. [1]
The evidence converges from both angles: carbs don't build extra muscle, and they don't generally improve the training quality that triggers growth either.
If you enjoy rice and it helps you hit your calorie target on a bulk — keep eating it. The calories are doing real work even if the carbs specifically aren't building muscle. If you want to cut carbs for a leaner recomp or simply prefer eating that way — the pooled data says your gains won't suffer, as long as total food and protein stay where they need to be.
The anxiety about losing muscle by cutting carbs was built on something eleven labs couldn't find evidence for. What they found instead was simpler: eat enough food, eat enough protein, and the carb slider moves freely.
Which raises the next question you can't avoid once this one is settled. If carbs don't affect how much muscle you build, do they affect how hard you can push in the gym? Can you still hit the same squat on half the carbs? Six controlled trials already tested that.
The finding doesn't land the same way for everyone.
If the goal right now is gaining size, the risk of dropping carbs isn't muscle loss — it's accidentally eating less food. Carbs are the easiest macro to eat in volume, and removing them without replacing the calories elsewhere is how a bulk stalls.
If the goal is getting leaner while keeping muscle, this study says the carb number is a free variable. Total food and protein are the constraints. The carbs adjust to preference, not to a formula.
What other research found
What this means for you
Several trials in this meta-analysis directly compared ketogenic diets against normal carb intakes during resistance training. The muscle growth results were the same across the board — keto didn't cost anyone gains.
The companion review from the same research group found the same pattern for strength: 39 of 49 studies showed no performance benefit from extra carbs, and all 16 that matched calories found no difference at all.
The one thing to watch is total food intake. Keto tends to blunt appetite, which is useful for fat loss but can quietly undercut a bulk.
This is where the calorie-vehicle finding bites hardest. One study in the meta-analysis found that the higher-carb group ended up in a substantially larger energy surplus despite both groups reporting similar intakes.
The muscle growth was the same regardless of carb level — but the lower-carb group lost more body fat, suggesting they were eating less without realizing it.
Dropping carbs on a bulk is fine for your muscles. It's risky for your calorie target.
Nine of the eleven studies in this meta-analysis used whole-body scans that can't separate real muscle from stored glycogen and water. One study showed a 4.8% jump in "lean mass" in a single week after reintroducing carbs — nobody builds that much real muscle in seven days.
If a scan showed impressive lean mass gains during a high-carb phase, some of that number may have been glycogen flooding back into tissue, not real muscle. The two studies that measured actual muscle thickness found a slightly different story.
Before you change anything
Predominantly trained males aged 18 to 65 doing resistance training three or more days per week. That's who was tested across the eleven trials.
Only one study included women exclusively, and two included untrained beginners. Women and older adults are significantly underrepresented in this evidence base — the researchers flagged this themselves as a gap that future studies need to fill.
If you're a trained man in your twenties doing conventional gym work, the data directly represents you. If not, the findings don't contradict — they just haven't been tested as thoroughly in your group.
Every study ran for 12 weeks or less. The longest was 11 weeks. That covers a single training block, not a training career. Whether the null finding holds across months or years of training remains untested.
The studies also varied widely in how much they changed carb intake — from small supplemental differences to full ketogenic diets. Whether a specific carb dose matters differently than a broad high-vs-low comparison is a question this evidence base can't answer yet.
The researchers rated their own confidence in this finding as low — two out of four on a standard scale. That means future research could shift the conclusion.
The evidence can't rule out a small positive effect of carbs on muscle growth. What it can rule out is a moderate or large one. Across every study ever done on this question, no lab detected a meaningful difference.
That consistency — eleven independent teams finding the same thing — is what carries the signal, even with the small total sample of 227 participants.
The muscle question is answered — carbs aren't building it. But once you've freed your carb intake from muscle-growth anxiety, a new question hits the moment you walk into the gym: will the bar feel heavier?
Six controlled trials already measured whether carb intake changes how much weight you can move. The answer runs parallel to this one, but the details have their own surprises.
What This Study Found
All findings from this paper, in plain language.
- Across eleven controlled trials, eating more carbs made no measurable difference to how much muscle people built during strength training.
- The result held no matter which individual study was removed — no single trial was driving the finding.
- Even when total calories were matched between groups, the carb level still didn't matter for muscle growth.
- The two studies that measured actual muscle thickness with imaging found a slight advantage for the lower-carb groups — the opposite of what whole-body scans suggested.
- The researchers rated the overall certainty of evidence as low — two out of four — meaning future studies could change the conclusion.
- Whole-body composition scans may have confused glycogen and water stored in muscle with actual muscle tissue, inflating the apparent results in higher-carb groups.
- Lower-carb groups tended to lose more fat, likely because they were accidentally eating fewer total calories — not because carbs are inherently fattening.
- A typical strength-training session depletes less than half of your muscle's stored energy, well below the level where performance starts to suffer.
- Carbs appear to function as a calorie delivery system rather than a muscle-building signal — they help you eat enough food, but they don't independently trigger growth.
- The data rules out a large benefit of carbs for muscle growth, but can't completely rule out a small one — the range of possible future results includes both a tiny positive and a tiny negative effect.