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 - Explorer (archive footage)

Ivor Cummins

Self - Biochemical Engineer

Ancel Keys

Self (archive footage)

Jeffry Gerber

Self - Physician

George McGovern

Self - Politician (archive footage)

Gary Fetke

Self - Orthopaedic Surgeon