Gary Taubes as Self - Investigative Science Journalist / Author

Nina Teicholz as Self - Investigative Science Journalist / Author

Ancel Keys as Self (Archival footage) - Physiologist

Tim Noakes as Self - Scientist / Author / Professor Emerita

Mark Hyman as Self - Narrator / Nutritionist / Functional Medicine Physician

Bret Scher as Self - Cardiologist

Sarah Hallberg as Self - Obesity Specialist

Zoe Harcombe as Self - Obesity Researcher

Salim Yusuf as Self - Cardiologist

Robert Lustig as Self - Pediatric Endocrinologist

Jason Fung as Self - Diabetes Specialist

Bill Maher as Self - Comedian (archive footage)

Eric Westman as Self - Obesity Specialist

Jonny Bowden as Self - Certified Nutritionist

Dwight D. Eisenhower as Self - President (archive footage)

Alyssa Gallagher as Self - Certified Diabetes Educator

Brian Gaudette as Self - US Army Pilot

Brian Lenzkes as Self - Internal Medicine Physician

Doug Reynolds as Self - Founder and CEO, LowCarbUSA

Dave Asprey as Self - Founder, Bulletproof