How is gallbladder disease be caused by an unhealthy diet?

Yes: Yes, high fat, low fiber die diet is a contributing factor in formation of gall stone, by elevated cholesterol levels, obesity, & diabetes are preventable, but most important factor the genetic which is not preventable.

Cholesterol: We are not 100 percent certain on how this happens, but some gallstones are made of cholesterol. The assumption is that high cholesterol levels can induce the formation of gallstones, but this is not always the case. There re many factors associated with the formation of gallstones and sometimes dieting alternated with periods of food binges can be as bad and a promotor of gallstones.