People: There are nearly a billion people in the world overweight - about the same number as those who go hungry. This crisis is usually called: "the double burden".
Planet: There are increasing demands on land for food, feed, fuel and fibre. To produce UK food, we need about 5X UK's land surface - according to our 'Food Footprint'. (Food Footprints: What Why Who & How)
WHAT is "Sustainable" food? Our food needs to use less vital resources like oil, and emit less greenhouse gases (Environmental), treat those in food chain better (Social), and make money for business investment (Economic) Fuller Answer
WHY "Sustainable" food? - when we already have organic, assured, ethical, slow food, & fair trade?
Fuller Answer