[ashelmire]

> This implies higher requirements for protein and essential fatty acids. The body does not produce them, it must be brought in via animal proteins.

This is not true. Proteins and fatty acids are found in many common vegetables and it's not difficult to get a healthy balance of the above. Harvard's school of public health, recommends, "Get your protein from plants when possible" [1], and it's not hard to find many other sources suggesting the same.

1. https://www.hsph.harvard.edu/nutritionsource/what-should-you...

[dalore]

It's well known that plants can't/don't provide all essential nutrients without supplementing. B12 is a major one amongst others.

Yet the reverse is true.

Sidenote: I wouldn't put much stock in Harvard school of "nutrition". They have massive conflicts of interest with companies like Monsanto and also numerous problems with their methodology like oversimplification of the issues. https://www.forbes.com/sites/trevorbutterworth/2013/05/27/to...

[jdmichal]

Wikipedia has plenty of other citations, if you have issues with Harvard:

https://en.wikipedia.org/wiki/Protein_combining#Criticism

Summary: Yes, eating solely one food may eventually cause an issue. For instance, eating only rice would eventually cause a lysine deficiency -- on the order of ~88% of required amounts. Eating pretty much any other food that is not lysine-limited would likely be enough to make up the ~12% gap.