High Fiber Diet Theory
The idea behind very high fiber diets is that food passes through our system so fast that the body doesn’t have a chance to absorb all the calories eaten. So the more fiber you eat, the more calories will be excreted and the greater the weight loss.
High Fiber Diet Practice
There is no evidence to suggest that a diet which is very high in fiber leads to fast weight loss purely because of it’s fiber content. Fiber-rich foods are filling and because fiber is indigestible it has no calories. But eating lots of fiber does not guarantee weight loss. The only thing that guarantees weight loss is eating fewer calories than you expend. Moreover, the side effects of very high fiber diets can be highly discomforting for anyone accustomed to normal dietary patterns.
Diets with Fiber are Good: Diets with too much fiber are Not
Too much fiber may deplete certain vitamins. Furthermore, when food passes through the body too quickly, nutrients are not absorbed properly and this can lead to ill health.
Avoid it. Instead, choose a high carbohydrate, low fat diet with regular amounts of fiber.