Eat fruits, vegetables, or grains, and you'll digest loads of vitamins and minerals. What won't you digest? Fibre. That's because fibre is the part of plant-based foods that is nearly indigestible. Rather than being absorbed through digestion like other nutrients, two types of dietary fibre get to work in ways that can be especially beneficial for people with diabetes.

Insoluble fibre will not dissolve in water. This is "roughage," the skins and peels of fruits, of root vegetables, and of certain types of seeds and nuts. It passes through the body's digestive system mostly intact. On its passage through the body, insoluble fibre sponges up water, softens and adds bulk to stool, and "scrubs" the digestive tract, helping food to move through your system. In this way, insoluble fibre helps maintain regularity and prevent constipation. Insoluble fibre may also be a boon to those trying to lose weight. Since it takes a while to transit through the body, it may help you to feel fuller and eat less.

Soluble fibre does dissolve in water. You consume soluble fibre when you eat certain green vegetables, fruits, legumes (peas, beans, and lentils), oat bran, rice bran, psyllium, and barley. As soluble fibre transits the body, it becomes a gel-like substance that binds to the digestive tract. That gooey, gel-like fibre traps substances related to cholesterol, slows gastric emptying, and delays the small intestine's absorption of glucose. Lower cholesterol levels may help to reduce the heart disease risks people with diabetes face. And slowed-down digestion and absorption of glucose make it easier to manage post-meal blood glucose spikes. Some researchers believe that over time, repeated post-meal blood glucose spikes can double a person's risk of heart attack and stroke.

Most North Americans consume only 4 g to 12 g of fibre per day. The recommended daily intake should be upwards of 26 g to 35 g . And if you have diabetes, some authorities recommend that you consume up to 50 g per day.

Don't worry, fibre can be found in many foods. And since it is not digested, you won't have to worry about fibre adding calories to your daily count! Do add extra fibre to your diet gradually, as it can be taxing on your digestive system at first. Bloating is common, but will go away in a few weeks.

When choosing your sources of fibre, consider both fibre content and where that fibre falls on the glycemic index, which is a system that measures how much of an effect a food will have on blood glucose levels. Research has found that adults with type 2 diabetes who ate a diet rich in high-fibre, low glycemic-index foods had improved cholesterol profiles and better control of blood glucose.

Note: People with diabetes who are on insulin therapy must closely monitor their carbohydrate intake, but fibre is factored separately.

High-fibre foods

Fibre content (in grams)

split peas

16 g/cup

lentils

16 g/cup

raspberries

8 g/cup

avocado

7 g/cup

barley

6 g/cup

oat bran muffin

5 g/muffin

quinoa

5 g/cup

broccoli

5 g/cup

potato with skin, baked

4 g/1 medium potato

banana

3 g/1 medium banana

Consult with your physician, diabetes educator, dietitian, or other member of your health care team before making any changes to your diet. They can also help you come up with an appropriate meal plan if you are trying to add more fibre to your diet.