There is no need to reinvent the wheel here, I have taken the following extract directly from The Lean Muscle Diet.
"Fibre is the one type of carbohydrate that almost everyone agrees is beneficial. High fibre foods, like fibrous vegetables, have relatively few calories, and the calories they do have seem to serve a noble purpose. They either (a) keep food in your stomach longer - this slows down the surge of glucose in your blood, which in turn mutes the insulin response; or (b) speed up the transit of food though your system, which gives you bigger and more predictable bowel movements. The older you get, the more you appreciate those. (Trust me.)
Traditionally, fibre is classified as either soluble or insoluble in water. Soluble fibre is most often found in oats, barley, nuts, seeds, beans, lentils, peas, and some fruits and vegetables. It soaks up water in your stomach, forming a gel that stays in your stomach longer. Along with helping to keep blood sugar in check, it has been shown to lower cholesterol levels.
Insulouble fibre - found in vegetables and grains - comes in two broad categories. Fermentable fibre promotes the growth of 'good' bacteria in your colon, and is also thought to inhibit the formation of tumours. Non fermentable fibre speeds up the transit time of your meals - in one end, out the other.
The long term benefits of fibre are impressive. Studies show it protects against colon cancer, the third leading cause of cancer deaths in the United States. Increased fibre consumption reduces fasting blood-sugar levels in people with type 2 diabetes. It may also reduce blood pressure in people with hypertension.
All that aside from the benefit you're probably most interested in: weight control. Some research (and a few popular diets) suggests that fibre offers 'negative' calories: The more fiber in your diet, the less energy you can metabolize from the other food you eat. That's in addition to the 'bulking' effect, which increases both satiation (your stomach feels full faster) and satiety (you're less hungry between meals).
The current guideline suggest that men eat 38 grams of fibre per day, or 14 grams per 1000 calories (25 grams a day for women). You want to get your fibre from real food, since fibre supplements don't seem to be effective, at least against colon cancer. By contrast, whole grains and legumes are correlated with lower rate of diabetes, heart disease, cancer and stroke.
Whether this is because of fibre or other nutrients doesn't really matter. There's also the possibility that people who are naturally health- and fitness-conscious eat those foods because they've been told their supposed to. So of course those foods would then correlate with longevity, disease reduction, a lower body weight and all the other benefits of healthy, active living. All that really matters here is that they qualify as "whole or minimally processed" for the purpose of Luke's diet plan. It's up to you which ones you want to include, and in what quantities"
Here are some examples of where high quality fibre can be found....
Legumes - Split peas, navy beans and kidney beans
Cereals & Grains - Wheat, bran, oats and quinoa
Vegetables - Artichoke, spinach, brussel sprouts
Fruits - Prunes, raspberries, blackberries
Nuts & Seeds - Almonds, pecans, pumpkin seeds
For a more comprehensive journey into your new found interest in Fibre, contact Luke R. Davies.
Schouler. L. and Aragon, A. (2014). The Lean Muscle Diet, Rodale Inc, USA, P27-28.