Could use some help

I need food. Heading down to the supermarket I remember what I wrote last night about never checking the country of origin on anything I buy. Thinking I'm gonna do it this time. But hold on... how am I gonna make an evaluation of the products based on this information?

I have alot of researching ahead of me. I need to update myself on human rights and living standards in other parts of the world, on environmental issues and politic everything. And I am hungry.

So, just for now, can anybody give me any good rule of thumb? Are there any clear indicators that the making of a product was made possible through the slaughter of a rainforest, or that women and children have been exploited? Any tips are welcome.