Everything about dietary fiber and how to include it in dietary plans

September 16, 2020

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This article is available in Portuguese, French and Spanish. Published in colaboration with nutritionist Julie Saraiva Pais.

In today's sedentary population, with high consumption rates of processed products, many people report having irregular intestinal health, lazy bowels, or even constipation. Most rely on pharmacological products to soften the symptoms. Even though, it is known that good intestinal health is all about adequate intake of dietary fiber, intestinal microbiome modulation, adequate water intake, and regular physical exercise.

"In the UK, the average fiber intake for adults is 60% (18g) of what it should be (30g)." According to the Academy of Nutrition and Dietetics, "the Adequate Intake for fiber is 14 g total fiber per 1,000 kcal or 25 g for adult women and 38 g for adult men."

In this article, we'll be discussing the benefits of fiber in health and how to easily incorporate it into your nutrition clients' meal plans, using Nutrium.

What is dietary fiber?

There are many definitions of dietary fiber. According to the Institute of Medicine, dietary fibers are "nondigestible carbohydrates and lignin that are intrinsic and intact in plants", which means that they are resistant to digestion and absorptions small intestine.

On the other hand, fiber is also constituted by functional fiber, which are isolated nondigestible carbohydrates that have beneficial physiological effects. Prebiotics are a source of functional fiber that promotes the "selective stimulation of growth and/or activity(ies) of one or a limited number of microbial genus(era)/species in the gut microbiota that confer(s) health benefits to the host".

What are the types of fiber?

Fiber can be soluble or insoluble.

Soluble fiber when in contact with water, turns into a gel, increasing the intestinal transit time and interferes with the absorption of nutrients in the intestine, such as lipids and carbohydrates.

These are resistant to the small intestine's enzymatic action but easily fermented by the intestinal microbiota. The colon uses them as an energy source, resulting in an increase in bacteria and increased fecal bulk.

As a result of fermentable dietary fiber reaching the colon, a variety of gases are produced (hydrogen, methane, and carbon dioxide) and short-chain fatty acids (SCFAs), such as acetate, propionate, and butyrate. β-glucans, fructans, pectins, inulin, and some hemicelluloses are examples of od soluble fiber. These are available in fruit, vegetables, legumes, oat cereals, barley, and rye.

Insoluble fiber has a more prominent action in the colon activity as they are responsible for increasing fecal bulk, increasing stool frequency, and reducing intestinal transit time.

They are hydrolyzed by the gut bacteria allowing the proliferation of non-aggressive bacteria in the gut bacteria with protective effects on the colon wall. Lignin, cellulose, and some hemicelluloses are examples of insoluble fiber.

These are available in leaf vegetables, whole grains, and their products (for example, dark bread, whole rice, whole pasta, nonsugary breakfast cereals).

Most foods are constituted by one thrid of soluble fiber and two-thirds of insoluble fibers.

Benefits of dietary fiber

The adequate regular consumption of dietary fiber reduces the risk of disease, including cardiovascular disease (CVD), type 2 diabetes, cancer, hypertension, and some gastrointestinal diseases.

In addition to that, increasing dietary fiber consumption improves the lipidic profile, reduces blood pressure, improves glycemic control in diabetic patients, helps control body weight, and promotes intestinal health.

Dietary Reference Intakes for total fiber

Recommendations for dietary fiber are based on Adequate Intake (AI) or Recommended Intake (RI), as there are not enough data to establish a Recommended Daily Intake (RDI).

Recommended fiber intake according to the Institute of Medicine

	Men	Women
1-3 years old	19 g	19 g
4-8 years old	25 g	25 g
9-13 years old	31 g	26 g
14-18 years old	38 g	26 g
19-30 years old	38 g	25 g
31-50 years old	38 g	25 g
> 70 years old	30 g	21 g

Recommended Dietary Reference Value by The Scientific Advisory Committee on Nutrition (SACN)

	DRV
< 2 years old	N/A
2-5 years old	15 g
5-11 years old	20 g
11-16 years old	25 g
16-18 years old	30 g
> 18 years old	30 g

This recommendation is easily achieved daily if people prioritize the consumption of:

starchy foods: porridge, oat bran, high fiber breakfast cereals, sweet potato, potato with skin, wholemeal or wholegrain bread and pasta;
beans and pulses such as baked beans, hummus, and dahl vegetables: peas, parsnip, mixed veg (from frozen), green beans, carrot, canned sweetcorn, and broccoli;
fruits: pear, apple, raspberries and blackberries, plums and prunes, banana and orange;
seeds such as linseeds and chia seeds;
nuts such as almonds, hazelnuts, and peanut butter.

How to easily add fiber into your nutrition clients meal plans

If you use Nutrium in your nutrition business, planning, and meeting clients' dietary fiber needs are pretty straightforward.

When analyzing the client's nutritional needs and planning their macronutrient targets, you can also set their target for dietary fiber and compare it to the recommendation according to gender and age.

When creating personalized mean plans for each client, you can see the fiber amount in each food and in each meal. Additionally, you can see the global quantity of fiber throughout the day.