The global shift to a Western diet rich in meat and dairy is putting unprecedented pressure on the planet to feed a growing population. Could a more sustainable diet resolve health and hunger crises around the world? And would people really be willing to switch to a greener menu?

Just off Melbourne’s über-cool Brunswick Street, hipsters are queuing outside cult café Smith & Deli. But while the menu might be based on New York-style cuisine – pastrami sandwiches and home-cooked lasagne – here, things are a little different. Everything sold at Smith & Deli is 100% vegan.

The term ‘vegans’ tends to conjure up images of salad-grazing, stick-thin hippies. But a different vegan message of indulgence and junk food has taken over Berlin. Supermarket chain Veganz stocks vegan candy and meatless bacon strips. But isn’t vegan junk food the ultimate diet contradiction?

Only 3% of the UK population identify as vegetarian. But thanks to a switch in tactics, the movement is gaining pace – and a weekly slot in people's stomachs. Can meat-free Michelin-starred restaurants, celebrity chefs, and veg delivery services cure people's appetite for meat?