Michael Mosley

as Self / Presenter / Journalist

Fauja Singh

as Self / 100+ year old marathon runner

Luigi Fontana

as Self / Professor, Washington University School of Medicine

Joe Cordell

as Self / Calorie Restrictor on Optimal Nutrition (CRONy)

Valter Longo

as Self / Professor, USC

Krista A. Varaday

as Self / Professor of Nutrition, University of Illinois Chicago

Mark P. Mattson

as Self / Professor, National Institute on Aging

Clare Mosley

as Self / Wife / General Practitioner / Consultant