How are national dietary guidelines researched and set?

In this video, Professor Hilary Powers explains how national dietary guidelines are researched and set. Hilary is a member of the Scientific Advisory Committee on Nutrition (SACN), that advises Public Health England and other bodies on matters relating to nutrition and health.

Hilary is Professor of Nutritional Biochemistry at the University of Sheffield. She was chair of the SACN subcommittee that reviewed the scientific evidence resulting in new guidelines for vitamin D intake in the UK that were published in July 2016.