NewsWorks Tonight host Dave Heller interviews Yael Lehmann, Executive Director of The Food Trust and keynote speaker of a three day symposium on food security at the University of Pennsylvania.

"Feeding Cities: Food Security in a Rapidly Urbanizing World" brings together speakers from around the world to address issues of access to affordable and nutritious food and urbanization.

The symposium begins Wednesday, March 13 and run through Friday, March 15.

Listen to the extended audio interview above.