The challenges of the global food system are often framed around feeding the world’s growing population. The issue is about much more than scale, however, with population rising but also shifting in character from predominately rural to increasingly urban. In the latter half of the 20th century the world's urban population trebled in size and for the first time in human history, more than 50% of people were classed as urban dwellers. By 2050, two thirds of the planet’s population is expected to be living in urban areas. Urbanisation has brought tremendous socio-economic shifts. It is also one of the most important factors now shaping food systems, which are becoming more globalised and consolidated: increasingly centralised networks involving fewer individual actors are supplying a growing proportion of the world's food. With urbanisation and increasing affluence, diet is also changing, characterised by a high demand for meat, dairy products and processed food.