Numbers are from combining data from
foodemissions.com with public nutrient tables. You really shouldn't get your nutrition science from any of the PCRM people. These people have an animal rights agenda and many of them lost the credibility they had by contributing to Kip Anderson PETA propaganda "documentaries". But beside that, the point is, CO2 friendly sources of carbohydrates and fats are plentiful and easy. It's protein that is challenging.

I wrote on protein Vs fiber recently in response to the worst of the bunch from the PCRM crew, I don't think it will change your mind, but hopefully it can give you something to think about:

https://steemit.com/nutrition/@pibara/fiber-versus-protein