Fett is the German word for fat.

He is mentioned in this post about hyperinsulinemia: https://feddit.org/post/30229407 .

Belinda’s husband, Dr. Gary Fettke, was targeted by the processed food industry for his public opinion on the perils of excessive sugar consumption and for showing the potential to put patients with Type 2 diabetes into remission. This caused him to him to be ‘silenced’ by the Australian Health Practitioner Regulation Agency.

To clear Gary’s name Belinda did a lot of work looking into the organizations linked to the accusations that led to the silencing. Belinda’s information withstood Australian legal process, and the story has a happy ending; 2018 saw a clearance of those charges with a full apology from the Medical Board.