What Is Fiber?
“Dietary fiber is the edible parts of plants or analogous carbohydrates that are resistant to digestion and absorption in the human small intestine with completed or partial fermentation in the large intestine”
In other words, fiber is a carbohydrate that the body is unable to digest. Fiber is not broken down into glucose the same way that other carbohydrates are but instead, passes through the entire gastrointestinal (GI) tract undigested. Fiber is important for digestive health and the regulation of bowel movements, it keeps us fuller for longer and can assist with managing cholesterol and blood sugar levels. It has also been known to assist in preventing some diseases such as diabetes, bowel cancer and heart disease.
Fiber is a carbohydrate but as it's undigested it entitles itself to its own category. Some products may display 'net carbs' which is the total grams of carbohydrates less the total grams of fiber. For example, if there are 20g of carbohydrates and 10g of fiber, this leaves 10g net carbs. This can make the product more appealing to those who are carb conscious.
Insoluble fiber helps food move through the digestive system and controls and balances the pH (acidity) in the intestines. The benefits of insoluble fiber include; promoting regular bowel movements and prevention of constipation, moving toxic waste through the colon, increasing satiety (feeling fuller for longer) and may also aid with weight management.
Sources Include: green beans and dark leafy vegetables, fruit skins, root vegetable skins, whole-wheat products, wheat bran, seeds and nuts.
Soluble fiber helps hydrate stools, facilitate movement through the intestine, prevents digestion disorders and helps to slow the release of sugar into the blood stream, creating a less intense sugar spike. The benefits of soluble fiber include; lowering total cholesterol and LDL (bad cholesterol), reducing the risks of heart disease and it can also help regulate blood sugar levels in diabetic patients.
Sources include: fruits and vegetables, grains, flaxseeds, oats, barley, nuts, seeds and beans.
Daily Requirement for Fiber:
Men: 30g or more per day
Women: 25g or more per day
Pregnant Women: 18g per day
Breastfeeding Women: 27-30g per day
Adequate daily fiber intake can also reduce the risks of developing cardiovascular diseases, diabetes and other chronic diseases.
The above image represents some great sources of fiber.
Personal Trainer & Nutritionist
BcS of Science (Nutrition & Food Science)
Physiology & Human Nutrition