Sure, but you need to get the protein out in supplement for this to work. That's only possible in recent times.
If the climate is up to it. You can't keep pigs in Southwest Asia without special shelters, which contributed to making them forbidden.
Wait, what? Even if they weren't ideal, people in that part of world clearly perservered with pig farming regardless, hence why Jewish archaeological sites are noted for the lack of pig bones (and Abrahamic religion's dislike of pork). Clearly pork isn't the best meat, but people would eat it. Remember during the swine flu epidemic a few years back when Egypt ordered all pigs in the country to be killed--most all were owned by Copts who don't have the kneejerk opposition to pigs a Muslim might. Pig farming has a long, long history in the MENA region. It's even in the Bible. Jesus never condemns any group of pig farmers, and the worst thing regarding pigs is Jesus casts out some demon into a horde of swine (which then dies). That's a sign that pigs were a lesser meat for the people, but an important meat regardless. Pig farming was widespread in Jesus's time, and going by the Copts who lost their flocks to the swine flu epidemic, widespread since then. Pigs are dirty, but nothing aside from religion prevents pigs from being widespread in North Africa, the Middle East, etc.
Non-meat protein, lentils and buckwheat, among various crops, clearly sustained many people throughout history. Both are rich in nutrients (and highly tasty). East Asian nobility tended to prefer rice over other crops (and polished rice--white rice--at that), which led to the odd scenario where the peasants tended to have better nutrition than the nobles, because, at least in Japan and I believe Korea too and possibly China, they were eating more buckwheat.