Gary Taubes
Self - Investigative Science Journalist / Author

Nina Teicholz
Self - Investigative Science Journalist / Author

Ancel Keys
Self (Archival footage) - Physiologist

Tim Noakes
Self - Scientist / Author / Professor Emerita

Mark Hyman
Self - Narrator / Nutritionist / Functional Medicine Physician

Bret Scher
Self - Cardiologist

Sarah Hallberg
Self - Obesity Specialist

Zoe Harcombe
Self - Obesity Researcher

Salim Yusuf
Self - Cardiologist

Robert Lustig
Self - Pediatric Endocrinologist

Jason Fung
Self - Diabetes Specialist

Bill Maher
Self - Comedian (archive footage)

Eric Westman
Self - Obesity Specialist

Jonny Bowden
Self - Certified Nutritionist

Dwight D. Eisenhower
Self - President (archive footage)

Alyssa Gallagher
Self - Certified Diabetes Educator

Brian Gaudette
Self - US Army Pilot

Brian Lenzkes
Self - Internal Medicine Physician

Doug Reynolds
Self - Founder and CEO

Self - Founder and CEO

Dave Asprey
Self - Founder

Self - Founder