Both anorexia and bulimia increase the risk of death. In the developed world binge eating disorder affects about 1.6% of women and 0.8% of men in a given year. Anorexia affects about 0.4% and bulimia affects about 1.3% of young women in a given year.
If you are insisting that on average a page is 500 words or 4,000 words the equivalent of 8 pages. By simple math you saying the average book is 80,000-120,000 words, would mean on average a novel is 160-240 pages. These would be classified as short novels or more so novels for older kids or younger teens.
Generally, a novel has approximately 250 words per page. Chapters can be as short as 20, and as long as 40-50. It all depends on the writer/author and the novel. Some are less, and some are more. The editor works directly with the printer to set up the format and pages. Some have different preferences.