You may not be aware of this - not consciously, at least - but you do not control what you eat. Every mouthful you take is informed by the subtle tweaking and nudging of a vast, complex, global system: one so intimately woven into everyday life that you hardly even know it's there. The food system is no longer simply a means of sustenance.

It is one of the most successful, most innovative and most destructive industries on earth. It sustains us, but it is also killing us. Diet-related disease is now the biggest cause of preventable illness and death in the developed world - far worse than smoking.

The environmental damage done by the food system is also changing climate patterns and degrading the earth, risking our food security. Few people know the workings of the food system better than Henry Dimbleby, co-founder of the Leon restaurant chain, government adviser and author of the radical National Food Strategy. In Ravenous, he takes us behind the scenes to reveal the mechanisms that act together to shape the modern diet - and therefore the world.

He explains not just why the food system is leading us into disaster, but what can be done about it.