In the 'food deserts' of Memphis, Tennessee, dominated by fast food outlets and convenience stores, locals lack what seems a basic human right in the richer half of the city: a supermarket. With a big gap in life expectancy, are these Americans doomed to die younger than their neighbours – or can they fight for their right to nutrition?

• Divided Cities ep 1: Does Melilla really need a Trump-style wall?

• Divided Cities ep 2: Why Havana's taxi drivers vastly out-earn doctors