I posted a link to this over at /v/cordcuttercontent and thought FPH might enjoy it. This film is also known as "Criminally Insane." The Wikipedia article for the film explains:
The morbidly obese Ethel Janowski (institutionalized due to her bouts of paranoia, depression, and violence) is released into the care of her grandmother, despite Doctor Gerard's unease regarding Ethel's discharge. Upon moving into her grandmother's San Francisco home, Ethel begins consuming massive amounts of food, and repeatedly claims that the employees of the institution were trying to starve her to death. In an attempt to stop Ethel's gorging, Mrs. Janowski empties the refrigerator, and locks the cupboards. Ethel and her grandmother argue, and when the elder Janowski threatens to call the sanitarium, Ethel impales her with a knife, then mutilates the old woman's hand to get the cabinet key she was holding in a death grip.
There was actually a sequel to this in the 80s. It's complete schlock, but you do get to see Fat Ethel running around killing and eating.
[–] 3868376? ago
Aww it's a document