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)