Jim Abrahams

Self / Father / Founder, Charlie Foundation / Filmmaker

Vinnie Tortorich

Self / Narrator / Producer / Trainer / Author

Bret Scher

Self / Cardiologist

Gary Taubes

Self / Journalist / Author

Dave Feldman

Self / Software Engineer

Eric Westman

Self / Internal Medicine Doctor

Andreas Eenfeldt

Self / Physician

Drew Pinsky

Self / Physician

Georgia Ede

Self / Psychiatrist

Nina Teicholz

Self / Journalist

Vilhjalmur Stefansson

Self (Archival footage) / Explorer

Ivor Cummins

Self / Biochemical Engineer

Ancel Keys

Self (Archival footage)

Jeffry Gerber

Self / Physician

George McGovern

Self (Archival footage) / Politician

Gary Fetke

Self / Orthopaedic Surgeon