Can you elaborate on this a bit? I can't comprehend the concept of people growing a crop not being able to afford to eat it - if they're the ones growing it, t

Can you elaborate on this a bit? I can't comprehend the concept of people growing a crop not being able to afford to eat it - if they're the ones growing it, then they don't have to buy it at all, just sell less of it. And surely the high international demand for quinoa means that they're making much more money in trade than previously.