Protein, Lysine & Muscle Mass in Vegans

Just added to the Protein page at

“A study out of Boston published in 2011 but performed using data collected during the 1980s, found that vegan and non-vegan, middle-aged women had similar levels of muscle mass despite differences in protein intake of 1.0 g/kg/day for vegans and 1.3 g/kg/day for omnivores (14). However, the muscle mass was not measured directly – rather it was estimated using formulas based on creatinine clearance (a byproduct of muscle metabolism). The researchers believed the formulas to be accurate, but since they have not been validated on vegans it should be viewed with some uncertainty.

At 30 mg/kg/day, the vegan women did not meet the RDA for lysine which is 38 mg/kg/day. However, the study showed the vegan women to be consuming only 1511 kcal/day vs. 1866 kcal/day for the omnivores, yet their body mass indexes were very similar at 20.0 and 20.7 respectively. This could indicate that food intake for the vegans was underestimated, possibly due to a lack of data on vegan foods.”

More commentary: This is one of only two studies that have looked at protein status in actual vegans, the other study being one that measured serum albumin levels (12). While not conclusive, it provides evidence that vegans generally have adequate protein status.


12. Haddad EH, Berk LS, Kettering JD, Hubbard RW, Peters WR. Dietary intake and biochemical, hematologic, and immune status of vegans compared with nonvegetarians. Am J Clin Nutr. 1999 Sep;70(3 Suppl):586S-593S. (Link)

14. Andrich DE, Filion ME, Woods M, Dwyer JT, Gorbach SL, Goldin BR, Adlercreutz H, Aubertin-Leheudre M. Relationship between essential amino acids and muscle mass, independent of habitual diets, in pre- and post-menopausal US women. Int J Food Sci Nutr. 2011 Nov;62(7):719-24. Epub 2011 May 16. (Link)

6 Responses to “Protein, Lysine & Muscle Mass in Vegans”

  1. Jack Norris RD Says:

    Thanks to Reed Mangles of the Vegetarian Resource Group for pointing out that 30 g/day of lysine is implausible. I mixed up the amount per day with the RDA (which is mg/kg/day) in my original post which is now corrected above to say:

    “The paper lists the vegan’s lysine intake as 30 g/day, which is an implausibly high amount (the RDA for their average body weight is 2.0 g/day). I am contacting the authors to find out more info on that, and in the meantime will assume they meant 30 mg/kg/day. If that is correct, it means that the vegan women did not meet the RDA for lysine which is 38 mg/kg/day.”

  2. Jack Norris RD Says:

    Update: I heard from the author and he said that the amino acid units were wrong, and that they should have all been in mg/kg/day. So, I have once again corrected the post. It now says almost exactly what the original post says except the units on the lysine intake are in mg/kg/day instead of g/day.

  3. ja Says:

    So where do we find all that lysine in vegan protein? We know that vegan protein is not rich in lysine. And do we realy need that much lysine to bild muskle?

  4. Jack Norris RD Says:


    Legumes, quinoa, pistachios, and pumpkin seeds are high in lysine. I don’t know how much lysine is needed to build muscle and I’m sure it varies depending on the situation, but you should try to at least meet the RDA which can be found here:

  5. Zak Says:

    Hey Jack –

    I have been studying amino acids and doing some charting of amounts in foods I am eating compared to how much I need, especially regarding lysine. I eat beans as often as possible, but there are some days that I don’t take in any high lysine foods and end up short. On those days, I have been supplementing with lysine. I am interested in your thoughts on whether that is a good idea or problematic in any way. Thanks for your service!

  6. Jack Norris RD Says:


    It would depend on how many days a week you’re short, how short you are, and if you notice any health improvements from supplementing. I’m not aware of any harm that could come from it assuming you’re only making up for your dietary deficit, but it’s not something I’d recommend either. I’d focus on getting high lysine foods in your diet unless there’s medical reasons you can’t.

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