Fiber in foods are wholesome, which helps with digestive and cardiovascular health. It is truly in its purest form, a necessity that our body needs. But eating fibers, and substituting with some food alternatives, can help you reduce the waistline, and promote muscle growth.
Think about it, fiber (soluble or insoluble) either takes a while to digest or is non-digestible. It then reduces the spikes from insulin. And some even say, fiber "collects" some of the calories you consume, and then you are able to excrete it out.
So try this out. During your larger meals, if you have a simple carb, substitute it for a food source with higher fiber. Aside from losing weight, by just eating healthier, you will also promote weight loss and general health because of the vitamins and fiber you are consuming.