Dietary Fiber

Dietary fiber consists of non-digestible types of carbohydrates that originate from plant-based foods. These carbohydrates are usually polysaccharides that consist of sugar molecules bonded together. Our diets are becoming deprived of fiber as more and more populations of people are adopting western diets. Research corroborates that our lifestyles like diet, physical activity, and sleep play a role in developing chronic diseases. For that reason increasing fiber consumption in our diets will help us improve our metabolic and health overall.


Types of fiber

 There are two types of fibers, namely: soluble and insoluble fiber. Soluble fiber is found in fruits and vegetables, while cereals and whole-grained products provide insoluble fiber. When fiber, is ingested it is digested by gut microbiota hence causing fermentation. Between the two types of fibers, soluble fiber is readily fermented than insoluble cereal fibers.

Benefits of fiber 

Prevention of constipation: Fiber improves gut motility thereby, preventing and treating constipation.

Helps with weight loss and maintaining healthy body weight: Foods rich in fiber are low in calories and, take a while to digest, and are very filling. 

Improve insulin sensitivity and metabolic health: Increased consumption of dietary fiber has metabolic effects like an improved glycemic index of carbohydrates-rich foods. In addition to the above insoluble fiber reduces the risk of type 2 diabetes.

Improve lipid profile: dietary fiber helps lowering cholesterol. See ABOUT CHOLESTEROL

Healthy gut microflora and metabolites: Boosting our dietary fiber intake will consequently result in a healthy and diverse gut microflora that underlies normal physiology, including normal immune development, metabolic and appetitive pathways, and even regulation of normal mental and emotional functioning.

Lowers and treats inflammation: Studies suggest that low consumption of dietary fiber is a risk for inflammation. Optimum dietary fiber intake establishes and maintains a healthy, viable, and diverse colonic microbiota. Consequently, this limits the production of inflammatory factors.

Reduce risk for development of depression: The relationship between fiber intake and risk for the development of depression remains partly understood. There has been a hypothesis which states that inflammation may mediate a link between dietary fiber and depression. Hence, possibly, reducing the risk for the development of depression. Research suggests that a healthy diet improves depressive symptoms in adult patients with poor-quality diets. 


Cardiovascular disease: Consumption of ultra-processed foods impoverished of dietary fiber links to increased risk of CVD. Ultra-processed foods are rich in trans-fats and sugars that make one susceptible to CVDs. Increased dietary fiber intake lowers the risk of mortality from coronary heart disease and all cancers. 

Colorectal carcinoma (CRC) prevention: Colorectal carcinoma is a type of cancer that affects the colon and the rectum. Research indicates that it is the third most common cancer globally. A comparison between individuals with the highest and lowest fiber intake, conducted through a meta-analysis to investigate the correlation between dietary fiber and risk of colorectal carcinoma, revealed a protective role of dietary fiber. 

Reduces Mortality: From one meta-analysis based on seven prospective cohort studies, there was a record of 11% reduction in all-cause mortality for each 10 gram per day increment of fiber. Concerning the type of dietary fiber consumed, cereal fiber seemed connected with the strongest inverse association with mortality.

 Recommended daily intake of dietary fiber

 Recommended daily intake is from 25g to 35g each day for adults. That is between 25-32g a day for adult females and 30-35 g a day for the adult male. Children and older adults require less dietary fiber depending on age. They need approximately 3-4g/MJ.


How to include fiber in your diet

We have learned that dietary fiber is available from fruits, vegetables, cereals, and whole grains. Include a variety of foods in your diet so that to achieve an optimum fiber intake. The following are simple ways of including fiber in your diet every day.

  •  Snack on fresh fruits, vegetable sticks, unsalted nuts or seeds
  •  Include loads of vegetables of your liking in your every meal, either as a side dish, stews, or curries.
  •  Choose whole foods like wholemeal bread or high fiber white bread, whole-wheat pasta, or brown rice.
  •  Cook potatoes with their skins on. You can either bake or boil them.
  •  Put in pulses like green grams, lentils, beans, and chickpeas to stews, curries, and salads.
  •  Include nuts and seeds in your diet. Examples include almonds, cashews, groundnuts, chia, flax, pumpkin, etc. 
  •  Go for a higher-fiber breakfast cereal such as plain whole-wheat biscuits (like Weetabix) or porridge, as oats are also a good source of fiber. 


  1. Monteiro, Carlos A et al. “Ultra-processed foods: what they are and how to identify them.” Public health nutrition 22,5 (2019): 936-941. doi:10.1017/S1368980018003762
  2. Swann, Olivia G et al. “Dietary fiber and its associations with depression and inflammation.” Nutrition reviews 78,5 (2020): 394-411. doi:10.1093/nutrit/nuz072
  3. Threapleton, Diane E et al. “Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis.” BMJ (Clinical research ed.) 347 f6879. 19 Dec. 2013, doi:10.1136/bmj.f6879
  4. Gianfredi, Vincenza et al. “Is dietary fibre truly protective against colon cancer? A systematic review and meta-analysis.” International journal of food sciences and nutrition 69,8 (2018): 904-915. doi:10.1080/09637486.2018.1446917
  5. Stephen, Alison M., et al. “Dietary Fibre in Europe: Current State of Knowledge on Definitions, Sources, Recommendations, Intakes and Relationships to Health.” Nutrition Research Reviews, vol. 30, no. 2, 2017, pp. 149–190., doi:10.1017/S095442241700004X.


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