Gary Taubes

Character: Self - Investigative Science Journalist / Author

Nina Teicholz

Character: Self - Investigative Science Journalist / Author

Ancel Keys

Character: Self (Archival footage) - Physiologist

Tim Noakes

Character: Self - Scientist / Author / Professor Emerita

Mark Hyman

Character: Self - Narrator / Nutritionist / Functional Medicine Physician

Bret Scher

Character: Self - Cardiologist

Sarah Hallberg

Character: Self - Obesity Specialist

Zoe Harcombe

Character: Self - Obesity Researcher

Salim Yusuf

Character: Self - Cardiologist

Robert Lustig

Character: Self - Pediatric Endocrinologist

Jason Fung

Character: Self - Diabetes Specialist

Bill Maher

Character: Self - Comedian (archive footage)

Eric Westman

Character: Self - Obesity Specialist

Jonny Bowden

Character: Self - Certified Nutritionist

Dwight D. Eisenhower

Character: Self - President (archive footage)

Alyssa Gallagher

Character: Self - Certified Diabetes Educator

Brian Gaudette

Character: Self - US Army Pilot

Brian Lenzkes

Character: Self - Internal Medicine Physician

Doug Reynolds

Character: Self - Founder and CEO, LowCarbUSA

Dave Asprey

Character: Self - Founder, Bulletproof