In the West, our diets are more varied (and more complicated) than ever. Unlike for the majority of human history, our sources of nutrition our no longer dictated by what is immediately, geographically, available to us. Instead, it is dictated by our taste, and whatever we pick up on a whim to make dinner with in Tesco Express: global produce that was once inaccessible, from bananas to avocados to quinoa. These foods have become a staple part of modern, middle-class, health-conscious diets - often without a second thought to how they got here. And, more often than not, these items remain available and relatively fresh on our supermarket shelves at any time of year.