This diet is pretty much the standard in many poor parts of the world - rice, beans, and fresh vegetables (in season). Billions of people across the planet have figured out that it's cheap and nutritious. Glad he could figure it out on his own too.
Many people in poor parts of the world get their daily B12 from fecal contamination in the water supply. It's actually an issue because cleaning up the water supply makes them deficient.
