No, it is not a myth, and the question has been settled by trials that measured muscle rather than collected opinions. In 2021, nineteen vegan men and nineteen omnivorous men completed twelve weeks of supervised resistance training with protein intake matched at 1.6 g per kilogram of body weight per day. Both groups gained the same vastus lateralis cross-sectional area, the same type I and type II fibre areas, the same leg-press strength. No between-group difference on any variable.

So what matters is not whether meat is on the plate. It is the number. And that number has been measured too: beyond roughly 1.62 g of protein per kilogram per day, additional intake adds nothing further to fat-free mass. The whole practical question of vegetarian muscle gain sits in the gap between that threshold and what a meat-free plate actually delivers.

What the trials measured, and what they did not

Three publications speak directly to the question in the title of this page.

The first is the meta-analysis by Robert Morton and colleagues, published in 2018 in the British Journal of Sports Medicine: 49 studies, 1863 participants, all doing at least six weeks of resistance training. Protein supplementation does increase gains in fat-free mass and strength, but a two-phase break-point analysis found a ceiling. Past a total intake of about 1.62 g/kg/day, extra protein produced no further measurable gain in fat-free mass. The effect also shrank with age and was stronger in already-trained individuals.

The second is the Brazilian trial by Victoria Hevia-Larraín, published in 2021 in Sports Medicine and described above. Its value is methodological: both groups were brought to the same intake, the vegans with soy protein isolate, the omnivores with whey. When the only variable that changes is the source of the protein, the source changes nothing.

The third is a 2025 meta-analysis of randomised controlled trials in Sports Medicine - Open: eight trials, 188 participants, 46% women, aged 20 to 65. No significant difference in upper body, lower body or overall muscular strength between plant-based and omnivorous diets.

These studies have limits worth naming. The 2021 trial recruited untrained young men, ran for twelve weeks only, and required supplementation in both arms to reach the target. The 2025 meta-analysis rests on 188 people in total, which is not many. Nobody has followed experienced vegetarian bodybuilders across several years. What is established is that at equal intake and equal training, source makes no measurable difference over twelve weeks. That is not the same as saying a vegetarian diet is easier to run: it is simply as effective, once the target is met.

How much protein, exactly

Swiss authorities set the general frame. The Federal Commission for Nutrition report published by the Federal Office of Public Health places adult protein intake between 0.8 and 2.0 g/kg/day, the upper bound being a precautionary limit reflecting uncertainty about the effects of higher intakes. It gives roughly 1.5 g/kg/day for adult athletes, within a range of 1.0 to 2.0, and notes that separate recommendations for strength and endurance athletes are no longer made. As a share of energy, protein should cover 10 to 20% of intake.

The 2017 position stand of the International Society of Sports Nutrition gives 1.4 to 2.0 g/kg/day for building and maintaining muscle mass. The top of the Swiss range and Morton’s measured ceiling converge around 1.6 to 2.0 g/kg/day.

For a 75 kg person that means 120 to 150 g of protein a day. That is the useful target. Pushing to 200 g accelerates nothing: the ceiling has been passed, and the Federal Commission report notes that raised protein intake is contraindicated in renal insufficiency. Outside that case, no adverse effect is documented within this range in healthy people.

What a day that hits the target actually looks like

Recommendations stay abstract until somebody weighs them. Here is a full day calculated from the Ciqual 2020 composition table published by ANSES, ovo-lacto-vegetarian, with no protein powder or supplement.

Breakfast: 80 g rolled oats, 300 ml calcium-fortified soya drink, 30 g almonds, a 120 g banana. Lunch: 250 g cooked green lentils, 150 g cooked brown rice, 150 g broccoli, 10 g olive oil. Snack: 250 g fat-free quark, 60 g wholemeal bread, 20 g peanut butter. Dinner: 200 g plain tofu, 300 g cooked wholewheat pasta, one red pepper, 10 g rapeseed oil.

The calculated total: 2598 kcal, 132.5 g protein, 292 g carbohydrate, 82.8 g fat, 65.9 g fibre, 23.1 mg iron, 17.3 mg zinc, 1265 mg calcium, 861 mg magnesium.

For an 80 kg person that is 1.66 g/kg, above the 1.62 ceiling. Protein supplies 20.4% of energy, at the top of the federal report’s 10 to 20% range. In other words: the target is reachable with ordinary foods, without supplements, and without contortion.

One figure in that day deserves a pause: 65.9 g of fibre. The NHS recommends 30 g a day and reports average intakes around 20 g. This day supplies more than double the recommendation. That is the real obstacle in vegetarian muscle gain, and it never appears in articles that reduce the whole thing to motivation.

The problem is not the protein, it is the volume

A 150 g portion of tofu supplies 20.1 g of protein for 222 kcal and 0.8 g of fibre. A 200 g portion of cooked green lentils supplies 20.2 g of protein for 254 kcal, but 16.9 g of fibre. Same protein, twenty times the fibre.

When you are stacking four to six protein feedings a day plus an energy surplus on top, that difference decides the outcome. You fill up, you bloat, you skip the evening snack, and the target is missed. The answer is not to drop pulses, whose iron, zinc and potassium are valuable, but to spread the load.

Three levers work. First, alternate dense low-fibre sources (tofu, seitan, quark, eggs, dairy if the diet includes it) with high-fibre ones (pulses, wholegrains). Second, shift pulses towards the meals furthest from training if digestion suffers during sessions. Third, use fat as a calorie ally: 20 g of nut butter supplies roughly 127 kcal with no digestive bulk at all, which buys energy without buying volume. Soaking and long cooking of pulses also improves tolerance as the ration climbs.

Reference portions, in real grams

All values come from Ciqual 2020, for the stated portion.

Food	Portion	Protein	Energy	Fibre	Iron	Zinc
Plain tofu	150 g	20.1 g	222 kcal	0.8 g	3.6 mg	1.9 mg
Packaged seitan	100 g	20.6 g	134 kcal	0.9 g	1.5 mg	1.2 mg
Tempeh	100 g	16.1 g	157 kcal	6.2 g	1.7 mg	1.3 mg
Cooked green lentils	200 g	20.2 g	254 kcal	16.9 g	4.9 mg	2.5 mg
Cooked red kidney beans	200 g	19.3 g	232 kcal	23.2 g	4.6 mg	1.9 mg
Cooked chickpeas	200 g	16.6 g	294 kcal	16.4 g	2.6 mg	2.2 mg
Fat-free quark	200 g	15.9 g	99 kcal	0 g	0.3 mg	1.0 mg
Eggs	2 (100 g)	12.7 g	140 kcal	0 g	1.9 mg	1.0 mg
Rolled oats	60 g	8.0 g	220 kcal	6.1 g	2.4 mg	2.0 mg
Cooked quinoa	200 g	9.3 g	298 kcal	7.6 g	3.2 mg	2.4 mg
Fortified soya drink	250 ml	8.6 g	110 kcal	2.5 g	1.1 mg	0.6 mg
Almonds	30 g	5.6 g	180 kcal	3.8 g	1.0 mg	1.1 mg

One reading jumps out. Fat-free quark is the most efficient food in the table on protein per calorie. Tofu and seitan follow. Quinoa, routinely presented as a flagship vegetarian protein, delivers 9.3 g for nearly 300 kcal, less than half the tofu figure for more energy. It is a good food and a poor protein anchor.

Protein quality: what holds up, and what is out of date

The classic argument comes down to one word: leucine. Animal proteins, whey above all, contain more of it and digest faster, producing a higher peak in blood amino acids. That is measured and not disputed.

What is disputed is the conclusion drawn from it. In 2023, a team compared 30 g of milk protein with 30 g of a wheat, maize and pea blend in 24 young men, with muscle biopsies, in The Journal of Nutrition. Essential aminoacidaemia was clearly lower with the plant blend, roughly half that of milk. Muscle protein synthesis rates did not differ. The blood peak is an intermediate marker; it does not predict the outcome.

A systematic review of 24 studies published in 2025 in Nutrients states the condition: a single-source plant protein remains inferior to whey, but a well-formulated blend reaches comparable synthesis from around 30 g delivering roughly 2.5 g of leucine. The ISSN position arrives at the same landmark by another route: 0.25 g of protein per kilogram per feeding, or 20 to 40 g, with 700 to 3000 mg of leucine.

The practical consequence is simple, and it retires an old piece of advice on the way. The job is not to assemble every plate according to a grain-and-pulse complementarity rule, as though a badly matched meal were wasted. The job is to hit a sufficient dose per feeding, from varied sources across the day. Amino acid complementarity is a real biochemical fact, but it resolves over the day rather than the meal, and combining grains and pulses is good cooking practice more than a metabolic constraint.

In practice, for a 75 kg person: roughly 19 g of protein per feeding, four feedings, about 150 g across the day. That corresponds, for instance, to 150 g of tofu, 200 g of lentils, 200 g of quark and 60 g of oats with a fortified soya drink.

Training produces the stimulus; the plate only permits it

No protein intake builds muscle in the absence of mechanical stimulus. The dose-response relationship was quantified by Brad Schoenfeld in 2017 in the Journal of Sports Sciences, from 34 treatment groups across 15 studies: each additional weekly set per muscle group was associated with a gain of about 0.37%, and the gap between higher and lower volumes reached 3.9%.

The public-health landmark is more modest. The NHS recommends strengthening activities working all major muscle groups on at least two days a week, alongside 150 minutes of moderate activity. For muscle gain that is a floor, not a goal.

The mechanism itself is progressive overload: increasing load, repetitions or sets across the weeks. A frozen programme stops producing gains, whatever the protein intake.

The size of the energy surplus, and why it is overestimated

A surplus is needed, but its magnitude has been tested. A 2023 trial in Sports Medicine - Open assigned 21 trained lifters to maintenance energy, a 5% surplus or a 15% surplus, training three days a week for eight weeks. The regression analysis, the most informative given the small sample, showed that faster body-mass gain mainly increased skinfold thickness, that is fat, without a proportional increase in muscle thickness or strength.

Practical translation: a modest surplus of 200 to 300 kcal a day is enough. Doubling it accelerates fat gain, not muscle gain. The trial covers 17 completers over eight weeks, which limits its reach, but it points the same way as field experience.

On a vegetarian diet the difficulty is not creating the surplus, it is swallowing it before satiety arrives. Oils, nut butters, dried fruit and fortified plant drinks add calories without adding bulk.

Creatine: what it actually does for vegetarians

Dietary creatine comes overwhelmingly from meat and fish. Vegetarians therefore start with lower muscle stores, and they are the group that responds most clearly to supplementation.

A randomised placebo-controlled trial published in 2025 in Physiological Reports followed fifteen vegans and vegetarians through seven days of creatine monohydrate at 0.3 g/kg/day. Muscle creatine rose by 18.8 mmol/kg and fat-free mass by 1.15 kg. But peak and mean power output across repeated sprints did not change, and neither did phosphocreatine.

That result needs reading correctly. The 1.15 kg gained in a week is not muscle: creatine draws water into the muscle cell, and that is what the scale records. Creatine remains the best-documented supplement in sports nutrition, with 3 to 5 g a day of monohydrate as the standard maintenance protocol, and its medium-term value runs through better-tolerated training volume. It replaces neither protein intake nor load progression. Over seven days and fifteen participants it produced nothing on performance.

Iron, zinc and B12: the three genuine watch points

These are not inevitable deficiencies, but they are where a poorly built vegetarian diet comes apart.

Plant iron is absorbed less efficiently than haem iron, and the phytates in pulses and wholegrains slow that absorption further. The NHS sets requirements at 8.7 mg a day for men aged 19 and over and 14.8 mg for women aged 19 to 49. The weighed day above supplies 23.1 mg, which leaves headroom even allowing for reduced absorption. The levers are known: vitamin C at the same meal, tea and coffee kept apart from it, soaking and sprouting. Our page on plant iron absorption goes into detail.

Zinc follows the same logic. The NHS gives 9.5 mg for men and 7 mg for women, and phytates again cut the absorbed fraction. The weighed day supplies 17.3 mg. Tofu, pumpkin seeds, oats and soaked pulses are the main contributors, as set out in our page on vegetarian zinc sources.

Vitamin B12 is the one point that meal composition cannot fix. It is bacterial in origin. Vegetarians who regularly eat eggs and dairy get a modest amount; vegans need fortified foods or a supplement. The 2016 position of the Academy of Nutrition and Dietetics is explicit on this.

One very common piece of advice has to go: spirulina is not a source of B12. An analysis published in 1999 in the Journal of Agricultural and Food Chemistry found that 83% of the dominant cobamide in spirulina tablets is pseudovitamin B12, a form inactive in humans. Using spirulina as a safety net amounts to having none. Our page on B12 requirements covers the reliable forms.

What the Swiss recommendations say about the wider frame

The FSVO’s Swiss dietary recommendations for adults call for one portion of a protein-rich food a day, varying sources across the week, pulses at least once a week and meat no more than two to three times a week. One portion is defined as 60 g of uncooked pulses, or 120 g of plain tofu, tempeh or seitan, or two to three eggs.

Somebody in a muscle-gain phase obviously exceeds that frame: four daily protein feedings is not one portion a day. But the orientation does not change. Vary the sources, treat pulses as a staple, do not build the whole intake on a single product. A performance-oriented vegetarian diet resting on three shakers and two blocks of tofu is a poor diet, whatever protein figure it posts.

Reading the label, because table averages are averages

The table above gives mean values. Actual products vary, and they vary precisely on the entries that matter for muscle gain.

Tofu’s protein content tracks its water content. Ciqual gives 13.4 g per 100 g for plain tofu, 14.9 g for smoked tofu and just 4.57 g for silken tofu, roughly a third. A 150 g portion therefore lands anywhere between under 7 g and a little over 22 g of protein depending on which one you picked up. The packet’s nutrition panel is the only reliable figure here.

With soya drinks, fortification decides everything. An unfortified drink supplies 12 mg of calcium per 100 ml according to Ciqual; a calcium-fortified one supplies 98 mg. That is a factor of eight, and it applies to exactly the nutrient a dairy-free pattern is most likely to miss. The ingredient list shows fortification as calcium carbonate or as an algal extract.

With quark, the fat grade is worth a look. Fat-free quark supplies 7.95 g of protein per 100 g at about 49 kcal; the 3% version supplies 8.03 g at 77 kcal. Practically identical protein, more than half again the energy. In a building phase that may be wanted; in a maintenance phase, generally not.

For seitan and meat alternatives, also check the salt figure, which can run high in processed products and must be declared per 100 g.

It is also worth reading the protein figure per portion rather than per 100 g. A bar advertising 20 g of protein per 100 g often weighs 45 g, so it delivers around 9 g, less than half a useful single dose. The same shift applies to plant drinks, yoghurt alternatives and most products marketed as high protein: the eye-catching number on the front almost always refers to 100 g, while the amount actually eaten sits in small print on the back.

Six mistakes that cost results

Counting protein without weighing food. An article that says “1.6 g/kg” without a single weighed quantity lets nobody check whether they are hitting the target. Three days of weighing is enough to calibrate; habit takes over afterwards.

Treating quinoa as a protein. 9.3 g per 200 g cooked and nearly 300 kcal. It is a side dish, not a pillar.

Stacking pulses at every meal. The digestive ceiling arrives before the protein ceiling. Alternate with tofu, seitan, eggs and dairy where the diet allows.

Relying on spirulina for B12. It contains mostly an inactive pseudovitamin.

Inflating the energy surplus. Beyond about 300 kcal a day, the thing that grows fastest is skinfold thickness.

Believing creatine builds muscle. It supports better training volume; sets build muscle. The first days’ weight gain is intracellular water.

Adapting by profile

Women. Protein needs per kilogram are the same, but iron needs are markedly higher, 14.8 mg a day between 19 and 49 according to the NHS. The 2025 meta-analysis included 46% women and found no strength difference attributable to diet.

Over 50. Morton’s meta-analysis shows the effect of protein supplementation diminishing with age. With a blunter anabolic response, aiming at the upper part of the range and holding sufficient training volume becomes more important, not less.

Vegans. The protein target is unchanged, as the 2021 trial demonstrated on a strictly vegan group. What changes is B12, which becomes mandatory as fortified food or supplement, and calcium, worth watching if plant drinks are not fortified.

Renal insufficiency. The Federal Commission for Nutrition report is unambiguous: raised protein intake is contraindicated. This page does not address that situation, which belongs to medical follow-up.

Endurance sports. The priorities differ, with carbohydrate load coming first. Our page on vegetarian diets and endurance sport handles that case separately.

Limits of this page

The composition values come from Ciqual, a French table. Swiss products, particularly tofu and plant drinks, vary by brand; the label on the product you buy always outranks a table average. Composition tables also disagree with each other on the same food, sometimes by more than 20% on trace elements.

The trials cited run eight to twelve weeks with modest samples, fifteen to forty people. None follows experienced vegetarian athletes across several seasons. The weighed day presented here is a calculated example, not a prescribed plan: energy needs depend on weight, body composition and actual expenditure.

Finally, this page replaces no medical advice and proposes no individual dosing. Working with a registered dietitian remains the recommended route in the presence of a medical condition, ongoing treatment or a competitive context.

Frequently asked questions

Do you need meat to build muscle? No. At matched protein intake and matched training, the 2021 trial found no difference in mass or strength gains between vegans and omnivores over twelve weeks.

How much protein per day? Between 1.6 and 2.0 g per kilogram of body weight. Past roughly 1.62 g/kg, Morton’s meta-analysis finds no further gain in fat-free mass.

Do grains and pulses have to be combined in the same meal? No. Complementarity plays out across the day. What really counts is the dose per feeding, around 0.25 g per kilogram, and the daily total.

Is a protein powder necessary? No. The weighed day above reaches 132.5 g of protein without powder. A soy or pea isolate stays convenient when appetite or schedule limits meals.

Does creatine make you gain weight? It raises body mass quickly, about 1.15 kg in seven days in the 2025 trial, but that is largely intracellular water rather than muscle tissue.

Is tofu enough as a main source? 150 g supplies 20.1 g of protein for 222 kcal, which makes it an excellent base. Resting the entire intake on one food remains a bad idea for micronutrients.

How long before results show? The trials cited measure changes in muscle cross-section over eight to twelve weeks of supervised resistance training. Outside a supervised protocol, expect several months.

Do you have to eat protein straight after training? The ISSN position treats distribution every three to four hours as the main factor. The post-workout window matters less than the daily total and the regularity of feedings.

For more on sources and portions, see our complete guide to plant proteins, our method for decoding high-protein labels and our marinade techniques for tofu and tempeh, which make a daily protein base considerably easier to sustain.

Sources

• Federal Office of Public Health, Federal Commission for Nutrition, Protein in human nutrition: recommendations, 2011 (German).
• FSVO, Swiss dietary recommendations for adults.
• Morton RW et al., British Journal of Sports Medicine, 2018, meta-analysis of protein supplementation.
• Hevia-Larraín V et al., Sports Medicine, 2021, high-protein plant-based diet versus protein-matched omnivorous diet.
• Sports Medicine - Open, 2025, meta-analysis of plant-based diets and muscular strength.
• Pinckaers PJM et al., The Journal of Nutrition, 2023, plant-derived protein blend versus milk protein.
• Nutrients, 2025, systematic review of plant proteins and recovery.
• International Society of Sports Nutrition, position stand on protein and exercise, 2017.
• International Society of Sports Nutrition, position stand on creatine, 2017.
• Physiological Reports, 2025, creatine in vegans and vegetarians.
• Sports Medicine - Open, 2023, small and large energy surpluses.
• Schoenfeld BJ et al., Journal of Sports Sciences, 2017, training volume and hypertrophy.
• Watanabe F et al., Journal of Agricultural and Food Chemistry, 1999, pseudovitamin B12 in spirulina.
• Academy of Nutrition and Dietetics, position on vegetarian diets, 2016.
• NHS, iron, zinc and other minerals, fibre, physical activity guidelines for adults.
• ANSES, Ciqual 2020 composition table.