As someone who's traveled the undeveloped world pretty heavily, you would be surprised at how bad the "raw" food quality is; especially if poverty is very high.

As someone who's traveled the undeveloped world pretty heavily, you would be surprised at how bad the "raw" food quality is; especially if poverty is very high. Undeveloped doesn't mean "without access to industrialized goods", it just means industrial infrastructure of their own is lacking. You seem to be mixing undeveloped (Port au Prince, Khartoum, Dhaka, etc) up with "tribal". They still have access to pesticides, heavy metals, low-quality/toxic feeds, gasoline, etc; in addition to having generally very lax/non-existent regulations.