In the UK and the western world, we don’t eat enough fibre. The average adult gets 18g per day. When really we need to be getting around 30g per day, which only 5% of people do. Most of us often overlook the importance of roughage and fibre (I will be using both terms interchangeably). However, fibre does have an array of health benefits.
Benefits of consuming adequate fibre include:
- Appetite control
- Lowers diabetes risk
- Lower heart disease risk
- Gut health
What is fibre
Fibre or “fiber” as spelt in some parts of the world is; the part of the plant, which you body cannot absorb or digest. For instance your body can easily absorb the sugar in fruit. That will go straight through your intestines no problem. But as for fibre thats a different story.
Fibre is processed in different ways depending on the type of fibre.
This is the type of fibre, that dissolves in the water. When it’s combined with water it forms a gel substance. What happens is, it runs through the small intestine untouched. However when it reaches the large intestine, this is where it combines with water and bacteria to ferment.
Soluble fibre, is the fibre that can help aid in lowering diabetes risk, lowering blood sugar and lowering bad cholesterol.
Sources include of soluble fibre:
Unlike soluble fibre, inslouble fibre passes through the body intact. This means it doesnt get broken, digested or fermented.
Its role is to help regulate your gut. It brings water into your fecal matter, which allows passing through the body without strain. This decreases the risk of constipation and helps to promote good bowel movements. As well as that, it also helps increase the sensitivity of insulin, preventing the risk of diabetes.
Sources of insoluble fibre include:
Wholewheat carbohydrates (eg whole bread and pasta)
Health benefits of eating more roughage
There are an array of benefits people would experience if they upped their fibre, to the recommended intake:
One the easiest ways to eat fewer calories is to increase your fibre intake.
One reason being. Compared to other foods, fibre has a low energy density. This means 1kg of broccoli, for example, will have far fewer calories than 1kg of chocolate. Therefore due to its low calories and high volume, it’s able to signal fullness to the stomach sooner than the same number of calories of chocolate could. (1)
So just by increasing your roughage intake, you can make yourself fuller. Therefore you consume less calories and your weight is easier to control.
Lowers diabetes risk
Increasing fibre can help reduce diabetes risk in various ways.
One way being, helps reduce energy intake, meaning your weight will be better managed. Obesity is a great risk to diabates, so keeping a healthy way can alleivate that risk.
The other way it helps, is by lowering blood sugar and increasing insulin sensitivity.
Fibre lowers the amount of blood sugar because when you eat soluble fibre it stays in your intestine as it combines with water, it makes the content of your intestine thicker. Therefore this slows the rate at which sugar is absorbed. This means less insulin is secreted after a meal, which also helps with hunger too. (2)
Diabetes is a combination of high blood sugar and desensitised insulin.
Sugar builds up in the blood and if the insulin can’t put that sugar into your muscles and cells, this is what leads to all the nasty problems diabetes entails.
A 2016 study had 2 groups of people, with diabetes. One group had to consume 10-20g extra soluble fibre per day. The other group’s diet did not change. After one month, the group who consumed the extra fibre, had lower blood sugar and greater insulin resistance. Also unrelated to diabetes had better blood cholesterol too. (3)
The 20 g/day soluble DF (dietary fiber) group exhibited significantly improved fasting blood glucose and low-density lipoprotein levels, as well as a significantly improved insulin resistance index(Chen et al., 2016)
Lowers heart disease risk
There’s a large body of studies that show, eating more fibre reduces your risk of heart disease and cancer too. (4)
Our findings suggest that high dietary fibre intake is associated with a reduced risk of mortality from CVD and all cancers. These results support the current recommendation that high dietary fibre intake should be part of a healthy diet.(Kim & Je, 2015)
When our blood, accumulates lots of ‘bad cholesterol (which comes from a diet rich in saturated fat, such as butter, cheese and fatty meat, such as sausage), this can build up in our arteries and cause a blockage, which can lead to heart disease. However, when people consume diets high in fibre, this has been shown many times to reduce the amount of bad cholesterol in the blood. Thus lowering the chance of one of these clots forming. (5)
Soluble fibre is responsible for lowering bad blood cholesterol. This mechanism occurs by, soluble fibre within the small intestine binding to the bad cholesterol. This prevents cholesterol from entering the bloodstream. So instead of the cholesterol causing issues in your arteries, it will exit your body, via faecal matter. (6)
Mechanistically, the beneficial effects on reducing total serum cholesterol are attributed to soluble fiber’s ability to chelate cholesterol in the lumen of the small intestine and therefore reduced the absorption of cholesterol. Soluble fiber also increases the fecal excretion of bile acids, and this diverts hepatic cholesterol for bile acid production, thus lowering circulating levels of plasma LDL cholesterol(McRae, 2017)
Improves gut health
Insoluble fibre adds bulk to your stool. This helps soften it and makes it easier to pass out of your system. This help prevents the risk of constipation, by keeping you feeling regular. (7)
Adequate dietary fibre also helps with gut bacteria diversity. When undigested fibre reaches the large intestine, these get fermented, which produces various bacteria. The more diversity within the gut, the lower your risk of contracting certain diseases.
There are so many other ways fibre helps. Ways such as producing more mucus, which prevents the risk of infection. And fibre helps with stomach acid production, which is essential for breaking down various nutrients. (8)
There are an array of great sources of fibre, what I have done is list the number of grams each serving has, on the table below.
|Food||Grams of fibre per serving|
|Bran cereal (40g serving)||8.8|
|Wholemeal bread (2 slices)||5.4|
|Whole Wheat Spaghetti (75g uncooked, 17g cooked)||6.5|
|Frozen mixed veg (80g)||1.8|
|Frozen mixed berries (80g)||2.4|
|Lentils (half can 117g)||6.8|
|Baked beans (half can||7.5|
|Sweet potato 100g||2.6|
|Runner beans (80g)||2.7|
How much fibre do I need per day?
However, as we are all of different sizes and eat different amounts. A more accurate personalised number would be to eat at least 14g of fibre per 1000 calories of food. So if you eat 2000 calories per day, you want 28g of fibre. If you eat 3000 per day, then 42g of fibre. (6)
However as great as fibre is, you do not want to eat in excess, as that can lead to stomach upsets. So make sure not to consume more than 70g per day. (9)
Finally make sure to consume adequate liquid, as this will help the fibre do its job. So long as your urine is a light see-through yellow, you’re drinking enough liquid. (10)
How to increase fibre intake
It’s all well and good, knowing what are good fibre sources, but here are some of my favourite ways to increase your uptake:
- Leave skins on fruits and potatoes
- Make smoothies with fruits and vegetables (add protein powder if you want to make a balanced breakfast)
- Always opt for whole fruits instead of juice
- Use tinned beans and lentils in various dishes
- Opt for whole wheat sources when you can (whole wheat bread, wholewheat pasta, etc) – not brown rice though, that tastes gross
- Make vegetable soups, instead of throwing out vegetables
- Mix fruit, nuts and seeds in your yoghurt
- Always have a few bags of frozen veggies in the freezer
- Make curries, with tinned beans lentils and frozen veg
As you can see, although overlooked, fibre is very important in out diets. So instead of worrying about small details such as supplements, look at getting enough roughage, as that is a far easier win.
As always if theres anything else you want to know, please let me know.
Josh is a Registered Associate Nutritionist, with the Association for Nutrition (AFN). He completed his degree in Nutrition at the University of Roehampton in 2021. He passed with a First Class with Honours.
Josh is also a tutor for up-and-coming Personal Trainers, where he teaches a Level 4 Advanced Nutrition course. This is for Personal Trainers looking to upskill their nutrition knowledge. This is done at Norfolk Health & Fitness.