For years, the idea that real strength requires meat has been repeated in gyms, coaching manuals and sports nutrition conversations. Animal protein has long been considered the gold standard for building muscle and many assume plant-based diets just can’t match it. But with more clients choosing vegan diets for health, ethical or environmental reasons, the question has never been more relevant. Can a vegan diet truly support strength gains?
Let’s explore the concerns, review the latest research and see what this means for coaches working with plant-based clients.
Why Some Still Doubt Vegan Diets for Strength
The scepticism doesn’t come from nowhere. There are some known differences between plant and animal foods that are worth discussing.
One of the main reasons vegan diets are sometimes questioned in the context of strength training is the difference in leucine content and protein quality compared with animal-based foods. Leucine is an essential amino acid that plays a central role in triggering muscle protein synthesis, that is the process by which muscles repair and grow after training. While it’s present in plant proteins, the concentration per gram is often lower than in animal proteins such as whey, eggs or meat. On top of this, some plant proteins are less digestible, meaning the body absorbs and utilises them less efficiently. These factors have contributed to the perception that plant proteins are inherently less effective for building muscle, even though research shows that total protein intake and variety of sources can offset these differences when planned carefully.
Another area that draws attention is micronutrient intake. Certain nutrients are more challenging to obtain from a vegan diet in sufficient amounts, particularly vitamin B12, iron, zinc, creatine and omega-3 fatty acids. Vitamin B12 for example, is found naturally only in animal-derived foods, so supplementation is essential for those following a vegan diet. Iron is present in plants in the non-heme form, which is less readily absorbed than the heme iron in meat and fish, making it important to pair iron-rich plant foods with vitamin C sources to boost uptake. Zinc supports immune function and recovery, while creatine and omega-3 fatty acids are closely linked to neuromuscular performance, energy production and reduced inflammation. Without attention to these nutrients, a vegan athlete could risk deficiencies that may impact training outcomes and recovery capacity.
A further consideration is the energy density of plant-based diets. Many plant foods are naturally lower in calories per gram than animal-based options. This can be an advantage for those trying to manage weight, but for athletes with high training volumes or naturally fast metabolisms, it can make it harder to maintain a calorie surplus. A surplus is often essential for muscle growth, and if the diet is built primarily around high-volume, low-calorie foods like leafy greens and vegetables, it may require a deliberate effort to include more calorie-dense plant options such as nuts, seeds, avocados, dried fruit and healthy oils to meet energy needs without feeling overly full.
These factors are real, but they’re not automatic deal-breakers. What matters is how the diet is put together and how well it matches the individual’s training demands.
What the Latest Research Says
The most comprehensive examination of this subject so far comes from a 2025 systematic review and meta-analysis conducted by López-Moreno and colleagues. This research focused exclusively on randomised controlled trials, which are considered the gold standard for establishing cause and effect, and compared plant-based diets with omnivorous diets in adults.
In total, the review included eight trials involving 188 participants aged between 20 and 65. The dietary interventions varied from vegetarian to fully vegan and were paired with different forms of structured training. Some participants followed resistance training programmes, others took part in high-intensity functional training, and some engaged in mixed routines that combined aerobic work, flexibility and strength training. The studies were relatively short in duration, running from as little as 10 days to as long as 12 weeks.
When the researchers pooled the results, they found no statistically significant differences in strength outcomes between the two diet types. For upper body strength, the standardised mean difference was −0.12; for lower body strength, it was 0.18; and for overall muscular strength, it was 0.21. In real-world terms, these numbers indicate that strength improvements were similar regardless of whether the diet included animal products or not.
A key detail in interpreting these results is that many of the studies made sure participants were consuming enough protein, typically at or above 1.6 grams per kilogram of body weight per day. This is a level widely recognised in sports nutrition as optimal for supporting muscle growth and strength development, and it may explain why both diet groups saw comparable progress.
The conclusions from this meta-analysis are supported by other work in the field. For example, Hevia-Larraín and colleagues (2021) compared high-protein vegan and omnivorous diets in untrained young men and found no difference in either strength gains or hypertrophy when protein intake was matched. Similarly, Isenmann et al. (2023) observed no decline in performance when trained individuals switched to a vegan diet for an eight-week period.
Taken together, these findings suggest that the type of diet is not the decisive factor in determining strength outcomes. The real drivers of progress are meeting total energy requirements, consuming enough protein and following a well-structured training programme.
What This Means for Coaches
This is where the practical application comes in. A well-structured vegan diet can support strength development just as well as an omnivorous one, but it does require careful planning.
Coaches with training from nutrition coach courses will recognise the importance of tailoring diets to meet protein, calorie and micronutrient needs. Even if you’re new to this area, taking a dedicated nutrition course can give you the knowledge to guide clients effectively.
Here are the main areas to focus on:
Protein Targets and Sources
- Aim for 1.6–2.2 g of protein per kg of body weight per day for strength-focused clients.
- Spread protein intake evenly across 3–5 meals to maximise muscle protein synthesis opportunities.
- Mix and match protein sources to cover the amino acid profile: tofu, tempeh, seitan, legumes, quinoa, nuts, seeds, and plant-based protein powders.
Micronutrient Awareness
- Vitamin B12: Supplementation is essential for vegans.
- Iron: Include iron-rich plant foods (lentils, beans, pumpkin seeds, spinach) with vitamin C sources to aid absorption. Monitor ferritin levels for at-risk clients.
- Omega-3s: Consider algal oil supplements to provide DHA and EPA.
- Creatine: Supplementation with creatine monohydrate (3–5g daily) can be particularly beneficial for vegan strength athletes.
Calorie Sufficiency
While plant-based eating offers plenty of nutrient-rich options, many of these foods are naturally lower in calories per gram compared with animal products. This can be beneficial for those aiming to manage their weight, but for individuals who are training hard and trying to gain muscle, it can make hitting daily energy targets more challenging.
One practical way to address this is by incorporating more calorie-dense plant foods into the diet. Nut butters, seeds, avocados, olives, dried fruit and oils can all provide a significant calorie boost without adding an unmanageable volume of food. These options not only contribute to overall energy intake but also supply healthy fats, additional protein and essential micronutrients that support training and recovery. For clients who struggle to eat large portions, adding these foods into meals and snacks can make it far easier to maintain a calorie surplus that supports muscle growth.
It’s also essential to monitor how the diet is working in practice. Encouraging clients to track their bodyweight alongside their strength performance gives a clear picture of progress. If strength gains are stalling and weight is dropping or holding steady, it may be a sign they are unintentionally in a calorie deficit. In these cases, adjusting portion sizes or increasing the frequency of calorie-dense snacks can make a noticeable difference. Consistent tracking and small, timely changes help ensure that energy intake stays aligned with the demands of training and the goal of building strength.
Training Alignment
Matching training volume and intensity with adequate recovery nutrition is very important for anyone looking to build strength, and this applies just as much to vegan athletes as it does to those following omnivorous diets. Hard training places a significant demand on the body’s energy stores and muscle tissue and without enough fuel and nutrients to support recovery, performance and progress can stall. Recovery nutrition means more than just hitting a protein target. It also involves replenishing glycogen with quality carbohydrates, providing sufficient healthy fats for hormonal balance and ensuring micronutrient needs are met to aid muscle repair and reduce inflammation. The more demanding the training programme, the greater the need to align nutrition closely with those demands.
For clients who are in a calorie surplus to support muscle growth, it’s also important to keep training progression steady and purposeful. Increasing training loads too aggressively can raise the risk of injury or excessive fatigue, while pushing calorie intake far beyond what is needed can lead to unnecessary fat gain. A measured approach, gradually increasing volume, intensity or load while maintaining an appropriate surplus allows the body to adapt and build muscle efficiently. This balance between smart training and targeted nutrition is what creates sustainable, long-term strength gains without compromising body composition.
Long-Term Considerations and Research Gaps
Most of the current research on vegan diets and strength training looks at short-term interventions lasting up to 12 weeks, leaving gaps in our understanding of long-term adaptations, outcomes in elite or high-volume strength sports and sex-specific responses to plant-based eating in resistance training. Until more data is available, the smartest approach is to focus on individual results, tracking progress, monitoring dietary compliance and making adjustments as needed to ensure both performance and nutritional needs are consistently met.
The evidence to date says a vegan diet can absolutely support strength gains when it is built to meet the demands of training. With the right energy, protein and nutrient balance, plant-based clients can progress in the weight room just as effectively as anyone else.
For coaches, the role is to help clients make that happen, not to debate whether it’s possible. With smart planning and evidence-based guidance, “getting strong on plants” moves from question to reality.
Reference
- López-Moreno, M., Viviani Rossi, E., López-Gil, J.F., Marrero-Fernández, P., Roldán-Ruiz, A., & Bertotti, G. (2025). Are Plant-Based Diets Detrimental to Muscular Strength? A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Sports Medicine – Open, 11:62. Click here to review the full research article.
- Hevia-Larraín, V., Gualano, B., Longobardi, I., Gil, S., Fernandes, A.L., Costa, L.A.R., et al. (2021). High-protein plant-based diet versus a protein-matched omnivorous diet to support resistance training adaptations: a comparison between habitual vegans and omnivores. Sports Medicine, 51, 1317–1330. Click here to review the full research article.
- Isenmann, E., Eggers, L., Havers, T., Schalla, J., Lesch, A., & Geisler, S. (2023). Change to a plant-based diet has no effect on strength performance in trained persons in the first 8 weeks – a 16-week controlled pilot study. International Journal of Environmental Research and Public Health, 20(3), 1856. Click here to review the full research article.
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