The plant based eating platform has become all the rage, yet people struggle to gain, and maintain, muscle when plant sources are their only avenue for protein consumption. Generally, the concentration of essential amino acids, specifically leucine, is lower in plant based protein sources than animal protein sources (Gorissen & Witard, 2018). Leucine is the key amino acid that triggers muscle protein synthesis (MPS), and low leucine interferes with, and is largely responsible for, the struggle with achieving a desirable amount of muscle tissue (hypertrophy) (Gorissen & Witard, 2018). While there is a synergistic response between leucine intake and resistance training, where physical activity reduces the amount of leucine necessary for MPS, this effect goes away if the training stimulus is reduced (Wilkinson et al., 2013).  

Generally, plant based protein, per serving size, is not high in enough in leucine content to stimulate MPS (Volpi et al., 2013). Thus, more of it is needed to meet the requisite leucine threshold for MPS, which is problematic if a person is aiming to control carbohydrate intake (Volpi et al., 2013). Thus, leucine must be attained elsewhere (Gorissen & Witard, 2018). The necessary dose of leucine to achieve MPS (and drive muscular hypertrophy) is ∼2–3g /meal (Wilkinson  et al., 2013), and in older adults this amount needs to be ∼3–4 g/meal (Volpi et al., 2013). This equates to ∼20–40 g of leucine rich protein per meal, dependent upon the person and source (Volpi et al., 2013).  

Recommendations for gaining, and maintaining, muscle tissue:  

  • Aim for 3–4g leucine per meal, which equates to 20–40 g of leucine rich protein (person and source dependent). 
  • Add 2g leucine (from BCAAs, EAAS or straight leucine powder) to most plant based meals (to meet the 3–4g/meal goal.  
  • Combine and swap protein sources up to increase leucine intake. 
  • Protein powders are the easiest way to meet low carb hi (complete) protein needs, but even vegan protein powders are low in leucine.  

Protein options:  

  • Non soy protein powders (pea, rice, corn, hemp, pumpkin, quinoa) 
  • Seitan 
  • Teff 
  • Tempeh 
  • Sunflower hache 
  • Spirulina 
  • Tofu 
  • TVP 
  • Lentils 
  • Beyond meat ‘can’ be an option but is high in fat!  

Have a question? Send me a message, I’m happy to chat! 🙂 

References: 

Gorissen, S. H., & Witard, O. C. (2018). Characterizing the muscle anabolic potential of dairy, meat and plant-based protein sources in older adults. Proceedings of the Nutrition Society, 77(1), 20-31. 

Volpi, E., Campbell, W. W., Dwyer, J. T., Johnson, M. A., Jensen, G. L., Morley, J. E., & Wolfe, R. R. (2013). Is the optimal level of protein intake for older adults greater than the recommended dietary allowance? Journals of Gerontology Series A: Biomedical Sciences and Medical Sciences, 68(6), 677-681. 

Wilkinson, D. J., Hossain, T., Hill, D. S., Phillips, B. E., Crossland, H., Williams, J., … & Atherton, P. J. (2013). Effects of leucine and its metabolite β‐hydroxy‐β‐methylbutyrate on human skeletal muscle protein metabolism. The Journal of Physiology, 591(11), 2911-2923. 

 

3.42g LEU to reach MPS 

Leucine goal: Leucine powder: 5G/scoop Pro powders/serving of leucine: Pumpkin: 1670mg / 1.67g consider adding 1/4 scoop leucine (1.67+1.25= 2.92) Pea:2008mg /2g no “need” to but consider adding 1/4 scoop leucine (2+1.25=3.25) Soy:1805mg / 1.8g consider adding 1/4 scoop leucine (1.8+1.25=3.05) Brown rice: 437mg/ .437g consider adding 1/2 scoop leucine (.437+ 3.75= 2.9) 

Need more of plant based protein to drive MPS (Gorissen) plant-based proteins exhibit 

inferior muscle anabolic potential compared with animal