Can You Build Muscle with a Plant-Based Diet? Science-Backed Insights

By Dr. Mark Evans, PhD, Optimum Nutrition, EMEA Performance Nutritionist

Key Learnings

• Protein and muscle building. Proteins, which are composed of amino acids, serve as the building blocks required to support muscle growth.

• Animal v Plant Protein Quality. Although plant protein has been known as an inferior protein source compared to animal protein due to its incomplete nature, you can overcome this limitation simply by enjoying a wide variety of plant-based foods daily.

• Digestibility Matters. The slower digestibility of plant-based proteins can be overcome by consuming larger quantities of plant protein, around 30 g per serving.

• Getting enough protein from plants. Eating a variety of plant-based foods provides high quality protein to the muscle. Although greater quantities of plant-based foods may need to be consumed to hit daily protein goals.

• Can you build muscle on a plant-based diet? Plant based diets can support muscle growth, with sufficient protein and calorie intakes, along with a consistent strength training programme.

• Practical Strategies for Muscle-Building on a Plant-Based Diet. Ensure you are hitting a daily protein intake of 1.6 g per kg body weight, include a variety of plant-based protein sources in your diet daily. If you’re not strictly vegan, consider adding dairy, eggs, or meats to your diet.

• Consider Supplementing. Adding a plant protein supplement to your day can be a convenient way to help hit daily protein targets.  Gold Standard 100% plant protein is an excellent choice for those seeking a high-quality, complete, vegan society approved protein shake. 

Contents

1. Protein and muscle building
2. Animal v Plant Protein Quality
3. Digestibility Matters
4. Getting enough protein from plants.
5. Can you build muscle on a plant-based diet?
6. Practical Strategies for Muscle-Building on a Plant-Based Diet

In recent years, the surge in popularity of plant-based diets has sparked a debate: Can you build muscle effectively with a plant-based diet, or is an animal-based diet the only way to go? As more people worldwide embrace plant-based eating, it’s essential to rely on evidence-based science to answer this question definitively. Although research in this area is still evolving, recent studies provide valuable insights. In this article, we’ll dive into the current literature to help you understand whether a plant-based diet can support muscle-building.

The Role of Protein in Muscle Building

To determine whether plant protein can adequately support muscle growth, it’s crucial to understand how protein supports the muscle building process.

A proper resistance training programme is the most important factor when building muscle1. Lifting weights creates small tears in the muscle, which subsequently supports muscle growth. However, for the muscle to grow bigger and stronger as you recover, the muscles need protein from your diet2. Proteins, which are composed of amino acids, serve as the building blocks required to support this muscle growth. In fact, for optimal muscle growth, the protein provided must contain all nine essential amino acids in the correct proportions.

Protein Quality: Animal vs. Plant

One of the main distinctions between animal and plant-based proteins lies in their quality. High-quality proteins are more effective in supporting muscle repair and maintenance. Protein quality is determined by the amino acid profile and the digestibility and absorption of the protein.

Animal proteins, such as meat and dairy, are considered high-quality complete proteins because they contain a full spectrum of amino acids in adequate amounts4. This ideal amino acid profile directly supports the muscle-building process. In contrast, many plant-based proteins, such as rice and pea, lack or are low in certain amino acids, making them incomplete proteins1.

However, you can overcome this limitation by combining different plant-based protein sources1 or simply enjoying a wide variety of plant-based foods daily. For example, pairing legumes, which are low in methionine but high in lysine, with grains that are high in methionine and lower in lysine, thereby, providing your body with a complete spectrum of all 20 amino acids, including all 9 essential ones.

Digestibility Matters

Another aspect to consider is the digestibility of proteins. Animal proteins are digested more rapidly than plant proteins4. Plant-based proteins contain elements like fibre and phytates that slow down their digestion and the delivery of amino acids to the muscles1. However, this digestibility issue can be overcome by consuming larger quantities of plant protein, around 30 g per serving1. This ensures an adequate delivery of essential amino acids to the muscle, to support its growth, which is particularly important for those on a plant-based diet. 

Getting Enough Protein from Plants?

The short answer is a resounding yes—you can indeed get enough protein from plants to support muscle building. However, plant-based foods typically contain lower protein content per serving compared to animal products. This means you may need to consume more plant-based protein sources, especially if you’re following a vegan diet, to meet your daily protein goals.

The required daily protein intake varies based on your age and activity level5. A general guideline recommends 1.6 g of protein per kg of body weight for individuals engaging in resistance training 3-5 times per week with a goal of muscle building. For example, a 70 kg athlete would require 112 g (70 x 1.6 = 112) of protein per day.

Scientific Insight: Can you build muscle on a plant-based diet?

A recent study conducted over 12 weeks compared the effects of a plant-based diet to a meat-based diet on muscle growth6. The study included two groups: one following a plant-based diet, and the other an omnivorous (animal-based) diet. Both groups engaged in regular resistance training and met daily protein recommendations of 1.6 g per kg. Surprisingly, both groups had similar increases in strength and lean muscle mass. This suggests that, regardless of protein quality, the critical factors for muscle building are meeting your daily protein goals and engaging in effective resistance training.

Practical Strategies for Muscle-Building on a Plant-Based Diet

Now that we’ve explored the science behind plant-based muscle building, let’s discuss practical strategies to ensure your plant-based diet supports your muscle-building goals.

1. Calculate Your Protein Needs

Start by calculating your daily protein intake based on your training objectives. Understanding the protein content of various plant-based foods and how much to consume will help you achieve your daily protein goals.

2. Combine Plant-Based Foods

Diversify your diet by combining different plant-based foods to provide your muscles with all essential amino acids. Incorporate a variety of legumes, grains, nuts, and seeds to ensure a well-rounded amino acid profile.

3. Include Animal-Based Foods

If you’re not strictly vegan, consider adding dairy, eggs, or meats to your diet. These animal-based sources offer a safety net, especially if the variety of plant protein in your diet is limited.

4. Distribute Protein Intake

To maximise muscle-building responses and overcome digestibility concerns with some plant sources, aim to eat approximately 30 g of plant-based protein per serving. This ensures a consistent supply of good-quality protein throughout the day.

5. Supplement When Necessary

For individuals with higher protein requirements, particularly vegans, protein supplements can be a convenient solution. Consider using a high-quality vegan protein supplement like Gold Standard 100% Plant Protein. This supplement, made from a blend of rice and pea protein, offers a complete amino acid profile to support muscle repair and growth* in conjunction with a resistance training program. It’s also an excellent choice for those seeking to reduce animal protein intake without compromising on protein quality.

Conclusion

In conclusion, the debate surrounding plant-based muscle building continues to evolve, but current research suggests that achieving daily protein goals and following a well-designed resistance training program are key factors. With the right approach, you can undoubtedly build muscle effectively on a plant-based diet, unlocking your full potential.

*Protein supports the growth and maintenance of muscle mass in conjunction with weights resistance training

References

1. Krzysztofik, M., et al. (2019). Maximizing Muscle Hypertrophy: A Systematic Review of Advanced Resistance Training Techniques and Methods. International journal of environmental research and public health, 16(24), 4897. https://doi.org/10.3390/ijerph16244897

2. Kerksick, C. M., et al. (2021). Plant Proteins and Exercise: What Role Can Plant Proteins Have in Promoting Adaptations to Exercise?. Nutrients, 13(6), 1962. https://doi.org/10.3390/nu13061962

3. Morton, R. W., et al. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British journal of sports medicine, 52(6), 376–384. https://doi.org/10.1136/bjsports-2017-097608

4. Stokes, T., et al. (2018). Recent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy with Resistance Exercise Training. Nutrients, 10(2), 180. https://doi.org/10.3390/nu10020180

5. Kerksick, C. M., et al., (2018). ISSN exercise & sports nutrition review update: research & recommendations. Journal of the International Society of Sports Nutrition, 15(1), 38. https://doi.org/10.1186/s12970-018-0242-y

6. Hevia-Larraín, V., 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 (Auckland, N.Z.), 51(6), 1317–1330. https://doi.org/10.1007/s40279-021-01434-9