Waste watcher

TRISTRAM Stuart has a habit of poking into trash bins at supermarkets - not the small ones at the front but the big container-size receptacles usually hidden from public view, in stuffy rooms near the carpark. Once he gets his hands on one, he prods and rummages through all that has been thrown out into the bins, before carefully fishing out food that remains edible. He then brings his collection home and makes a delectable meal out of it. Once in a while, he even organises events that can feed up to 5,000 people, all with food that would have otherwise ended up in the landfill.

His point of doing all this? To prove that there is a lot of good food going unnecessarily to waste in our food system. And that if this continues, with food production increasing so as to feed the world's nine billion mouths expected by 2050, all remaining wild places on earth will be lost to farmlands.

The 40-year-old author and campaigner - who sees food waste as one of the most important issues of the planet today - would know. One of the United Nations' champions for Sustainable Development Goal 12.3, Mr Stuart has trawled through reams of data, spoken to countless supermarket executives, and written a book on the issue. He is also a National Geographic Emerging Explorer, a World Economic Forum Young Global Leader, and the winner of international environmental award The Sophie Prize in 2011.