Fibre is essential for healthy digestion because it adds bulk and softness to stool, keeps things moving through your gut, and feeds the beneficial bacteria in your large intestine. It also helps meals feel more filling and supports steadier blood sugar and healthier cholesterol. Most Canadians eat only about half the fibre they need, so adding more, slowly and with plenty of fluids, is one of the simplest upgrades you can make.
What fibre is
Dietary fibre is the part of plant foods your body can’t digest. Instead of being absorbed, it travels through your digestive system, where it does several useful jobs. There are two main types, and most plant foods contain some of each.
| Soluble fibre | Insoluble fibre | |
|---|---|---|
| What it does | Dissolves in water and forms a gel that slows digestion | Doesn’t dissolve; adds bulk and helps material move through the gut |
| Main benefits | May help lower LDL cholesterol and steady blood sugar | Helps prevent constipation and promotes regularity |
| Good sources | Oats, barley, beans, lentils, peas, apples, citrus, psyllium | Whole wheat, wheat bran, brown rice, nuts, vegetables, fruit and potato skins |
Mayo Clinic explains that soluble fibre forms a gel-like material that slows digestion, while insoluble fibre supports the movement of material through the digestive system and adds bulk to stool.
How fibre helps digestion
Regularity and constipation relief
Fibre increases the size and weight of stool and softens it, making it easier to pass and lowering the chance of constipation.
Feeding your gut bacteria
Some fibres reach the large intestine intact, where gut bacteria ferment them. This “prebiotic” effect helps support a diverse community of microbes. Eating a wide variety of plant foods gives those bacteria a wider variety of fibres to work with. You can read more about this in our article on gut health.
Comfort, when added the right way
Fibre can relieve discomfort, but adding a lot at once can do the opposite. Mayo Clinic notes that adding too much fibre too quickly can cause gas, bloating and cramping. Go slowly, as described below.
Benefits beyond digestion
- Fullness and weight: high-fibre foods tend to be more filling than low-fibre foods, so you may eat less and stay satisfied longer.
- Blood sugar: fibre, especially soluble fibre, can slow the absorption of sugar and help improve blood sugar levels.
- Cholesterol: soluble fibre may help lower LDL (“bad”) cholesterol.
How much fibre do you need?
Health Canada says women need 25 grams of fibre per day and men need 38 grams, and that most Canadians get only about half that. Needs change with age; Dietitians of Canada’s Unlock Food lists the amounts by age group:
| Group | Grams per day |
|---|---|
| Children 1–3 years | 19 |
| Children 4–8 years | 25 |
| Girls 9–18 years | 26 |
| Boys 9–13 years | 31 |
| Boys 14–18 years | 38 |
| Women 19–50 / 51+ | 25 / 21 |
| Men 19–50 / 51+ | 38 / 30 |
| Pregnant / breastfeeding | 28 / 29 |
Use the Nutrition Facts table to compare products: the %DV for fibre tells you whether a food has a little (5% or less) or a lot (15% or more).
Practical ways to eat more fibre
At breakfast
- Choose oatmeal or a whole grain cereal and top it with berries, sliced banana, ground flax or chia seeds.
- Switch to whole grain bread for toast.
At lunch and dinner
- Add beans, lentils or chickpeas to soups, salads, pasta sauce, tacos and chili.
- Swap white rice and pasta for brown rice, barley, quinoa or whole grain pasta, or mix half and half to start.
- Fill half your plate with vegetables, and leave the skin on potatoes when you can.
For snacks
- Whole fruit (apples, pears, oranges, berries) instead of juice.
- Raw vegetables with hummus.
- Air-popped popcorn or a small handful of nuts.
A sample higher-fibre day
- Breakfast: oatmeal cooked with milk, topped with raspberries and a spoonful of ground flax.
- Lunch: whole grain wrap with hummus, spinach, grated carrot and chickpeas, plus a pear.
- Snack: an apple with a small handful of almonds.
- Dinner: lentil and vegetable chili over brown rice, with a side salad.
Increase slowly and drink enough fluids
Unlock Food advises that to get the health benefits of fibre, you slowly increase the amount you eat, stay physically active and drink plenty of fluids, which helps you avoid gas and bloating. Mayo Clinic suggests increasing over a few weeks, and notes that fibre works best when it absorbs water.
A simple plan:
- Week 1: add one higher-fibre swap per day, like whole grain bread or an extra serving of fruit.
- Week 2: add a serving of beans or lentils a few times this week.
- Week 3 and beyond: keep adding vegetables, whole grains and seeds until you’re close to your target.
- Every day: keep a water bottle with you and sip through the day. See our guide to hydration for more.
If you feel bloated, hold at your current level for a few days before adding more. Our article on reducing bloating has more tips.
Food first, supplements second
Whole foods give you a mix of fibre types along with vitamins, minerals and other plant compounds. Fibre supplements such as psyllium can be useful for some people, but it’s best to talk with your doctor or pharmacist before using them regularly, especially if you take medications.
When to check with a professional
Talk to your doctor or a registered dietitian before significantly increasing fibre if you have Crohn’s disease, ulcerative colitis, irritable bowel syndrome, diverticular disease, a history of bowel obstruction, or have recently had digestive surgery. Some people are told to follow a lower-fibre diet temporarily during a flare or recovery. See a doctor promptly if you notice a lasting change in bowel habits, blood in your stool, unexplained weight loss or ongoing abdominal pain.
Key takeaways
- Fibre keeps digestion regular, softens stool and feeds healthy gut bacteria.
- Aim for about 25 g a day (women) or 38 g (men); most people get about half.
- Get both types from oats, beans, lentils, whole grains, fruit, vegetables, nuts and seeds.
- Increase slowly over a few weeks and drink plenty of fluids.
- Check with a professional if you have a digestive condition.
FAQ
Does fibre help with constipation?
Yes. Fibre increases the size and softness of stool, which makes it easier to pass. Pair it with enough fluids for the best effect.
What are the easiest high-fibre foods to add?
Oatmeal, whole grain bread, beans and lentils, berries, apples and pears with the skin on, vegetables, popcorn, nuts and seeds like chia or ground flax. Swapping refined grains for whole grains is often the simplest first step.
Can I eat too much fibre?
Adding a lot too quickly can cause gas, bloating and cramping. Build up gradually and keep drinking fluids.