Lila...you make a good point. Even at induction levels, it's possible to get quite a bit of fiber. Let's also consider what many of these studies that demonize fat are based on; high carb AND high fat. They blame the fat because of scientific bias (it couldn't possibly be the carbs, right?) and ignore the possibility that it may be the high carb content of the diets of the subjects studied that caused the negative effects OR the combination of high carb and high fat or even the types of fats they were consuming (ie high in hydrogenated or processed vegetable oils). Something else that a lot of these article writers seem to ignore is that you are not intended to stay at induction levels of carb forever or even for the duration of your weight loss journey. Moving through all the phases gradually increases your levels of carbs and decreases your level of fats.
Same thing goes for the studies that claim fiber is absolutely necessary for good health. Is it the fiber or the vitamins, minerals, phytonutrients and antioxidants that high fiber (ie vegetables) foods contain? How do you isolate the effects of one from the other?