Most chefs prefer to let their food do the talking. If they have anything else to say, it goes into a cookbook. But for Rene Redzepi there is far too much to be discussed — above and beyond the brilliant, inventive dishes he serves at his restaurant, Noma, in Copenhagen and (temporarily) in Tokyo.

So, he came up with the idea of holding an annual gathering where he and his contemporaries could come together to share ideas and concerns relating to the all-encompassing subject of food. Now four years old, the MAD symposium draws chefs young and old from around the world to hear presentations by their peers, along with a supporting cast of farmers, activists, academics, sea urchin gatherers, climate scientists and more.

Held in a large red tent on the Copenhagen waterfront each summer, MAD — cunningly named after the Danish word for "food" — straddles a territory somewhere between a TEDx talk and a religious revivalist meeting, with a leavening of hip-hop sass and back-to-nature Woodstock vibes. Speakers have ranged from revered French cuisiniers, such as Michel Bras and Alain Ducasse, to Indian environmental activist Vandana Shiva, Los Angeles food truck celebrity Roy Choi and even a 12-year-old Scottish girl who blogs about her school meals.

In 2013, MAD3 opened with a graphic demonstration of butchering a whole pig. The following year Japanese soba master Tatsuru Rai prepared buckwheat noodles from scratch. It is this heady, eclectic mix that makes MAD such a compelling event.

Papers and videos from past MAD symposia can be viewed online at www.madfeed.co.