Thousands of Athenians have turned up to consume more than a ton of fruit and vegetables rejected by stores in an event that highlights the waste of food in advanced societies.

Despite the overcast sky, people lined up in a central square in the Greek capital on Sunday to eat briam, a casserole medley of vegetables, such as eggplant, zucchini, carrots and potatoes, as well as a dessert of fruit salad.

The event was part of a global campaign called "Feeding5000."

The organizers, global non-governmental organization Feedback, received the vegetables from farmers after they had been rejected by stores because they were misshapen, but otherwise perfectly edible, they said.

About a third of the annual global foodstuff production gets lost or wasted, Feedback says.