Fibre Facts without the Faff
I want to start by saying that a high fibre diet is not for everyone due to a number of reasons including diagnosed (or undiagnosed) gut conditions.
If you notice that you're experiencing uncomfortable gut symptoms (bloating, changes in bowel patterns) from any food, including fibrous foods, you should get in contact with your GP and / or a nutrition professional such as a dietitian or registered nutritionist.
Once a diagnosis has been given, a qualified food and nutrition expert can provide a nutritional care plan to make sure that you are getting the right type and amount of fibre for you.
Disclaimer done, lets get into it.
1. What is fibre? Why is it important?
Fibre is a term used to name all types of plant material which our digestive systems (gut) aren’t able to break-down and absorb. Fibre is often referred to as ‘bulk’ or ‘roughage’.
There are 2 main types of fibre: soluble (dissolvable in water) and insoluble (not able to dissolve in water). Most foods have a combination of both but will be particularly higher in one than the other. In real terms, this means that when we eat foods which are high in soluble fibre, it can dissolve in the fluid within our gut, creating a gel-like consistency. The benefit of eating foods high in soluble fibre include:
- lower blood cholesterol levels, which means better heart health
- control blood glucose (sugar) levels, which means better diabetes management for those who are diagnosed with pre-, type 1 or type 2 diabetes
- and slow the digestion of food so you feel full longer, which can help to aid weight loss to promote weight stability
When we eat foods which are high in insoluble fibre, this can’t be dissolved in the fluid within our gut but instead soaks up any fluid around it and so adds ‘bulk’ to our stools. The benefits of this type of fibre include:
- resolve constipation without the need of taking medication
-promote a healthy digestive system and regular bowel movements.
A high fibre diet consisting of both types has been shown to help lower your risk for colon cancer, heart disease, type 2 diabetes and manage digestive conditions. This makes fibre an essential nutrient to achieving a healthy diet.
We also have a third type of fibre, resistant starch, which is a type of soluble fibre which escapes digestion and ferments in the large intestine (lower gut) where is acts as food for our health gut bacteria. This source of food for our gut means that it can support a healthy environment for the good bacteria and help to fight and prevent infections caused by bad bacteria.
2. How much fibre do adults need each day and what happens to our body when we don’t get enough?
In the UK, the recommended about of fibre adults should aim to have a day is 30g a day. The World Health organisation (WHO) don’t advise a set amount of day but instead encourage adults to aim for 5 portions of a combination of fruits and vegetables a day to reach good fibre intake levels.
The average adult Brit only has about 18g of fibre a day which is only 60% of what we should be having.
Eating a diet which is regularly low in fibre is associated with poor digestion habits, increased risk of type 2 diabetes, poor heart health, development of gastro-intestinal conditions such are diverticulitis and has an increased risk of developing some cancers.
The increase in health risks is largely because a diet low in fibre means that it is low in whole-grains, whole-foods, fruits and vegetables (all of which are great sources of fibre) and is instead likely to be high in refined carbohydrate foods, meat, fats and ultra-processed foods
3. Please can you give some examples of fibre sources, especially those with a value angle.
For a food, meal or drink to say that they are high in fibre, they must contain 6g of fibre per 100g whereas it would only need to contain 3g of fibre per 100g for it be classed as being a source of fibre.
All fruits, vegetables and wholegrain foods contain fibre (in varying quantities and proportions). Examples of fruits which are good sources of fibre include pears, kiwis and papaya; all containing 3g of fibre/100g
Fruits which are high in fibre include berries, particularly raspberries, and dried fruits, such as figs which both contain around 7g of fibre / 100g.
Fibrous vegetables include parsnips, cabbage, aubergine and beetroot- all containing around 3g per 100g.
High fibre wholegrain foods include oats (8g of fibre /100g), wholemeal bread and brown pasta (each containing about 7g of fibre/100g).
We don’t eat 100g of food at a time so to put this into perspective a bowl of porridge with a handful of berries and a small handful almonds will contain 9g of fibre….that’s 30% of your recommended fibre intake for the day done in one meal!
Other great source of fibre (specifically resistant fibre) include baked beans (5g fibre/100g) and boiled green bananas (4g fibre/100g)
4. For foods that are fortified with fibre – what does this mean? Why is fibre added and which foods does this commonly happen with?
The World Health Organisation (WHO) define fortification in relation to food as a means of deliberately raising the nutritional profile of a food or drink item. Fortification methods can be used to increase micronutrients such as vitamin D in eggs and margarine or vitamin B12 in flour.
Health snacks and high protein drinks or meal replacements marketing themselves as having a high fibre content typically use chicory root extract or chicory inulin to increase fibre levels without compromising on the taste or texture of the snack, drink or meal.
Fibre may be added to attract people to purchase their product as ‘high fibre’ may be a sign to the consumers that it may be a healthier food choice.
5. Is there a best time of day to eat fibre (in the morning, before you exercise, etc) and are there any foods you can eat in combination with fibre to increase efficiency?
No matter what your baseline fibre intake, based on national average (18g fibre intake a day) it is likely that you are not reaching the recommended 30g each day so we would all benefit from making some diet changes to increase our fibre intake. It’s highly recommended that
We should aim to have sources of fibre with each meal (ie wholemeal foods and a portion of vegetables) and have at least one meat and fish-free evening meal a week. Meat or fish should be replaced with beans or pulses so that you still get your protein source
Having a high fibre at each mealtime has their unique benefits, for example
Breakfast: helps to make one feel fuller and more satisfied. Promoting brain activity and concentration to get us going for the day
Lunch and evening meal: stops that feeling of sleepiness which can happen after eating a heavy and low fibre meal. Will also stop those sweet sugar cravings from creeping up in the afternoon or in the evening.
I would be cautious about having a high fibre meal or snack close to when you plan to exercise or go a high intensity work-out which requires quick access to energy from carbohydrate foods.
Instead, aim to give yourself 45min-1hr gap between fibrous meal or snack and a workout. Opt for easily digestible whole foods ie a ripe banana, smoothie or yoghurt with honey if you have a smaller window between eating and your work-out.