Nutrition tips

About carbohydrates and fibre

by Katherine Jefferson

registered dietitian

About carbohydrates and fibre

Types of carbohydrates: Sugars, Starches, Fibre
How do we use carbs: Provide energy instantly or store it for later use
How Much to eat: Generally consume at least 130g of carbohydrates per day, which should make up 45-65% of total calories. This may vary in some cases.
If you eat too much: Risk of weight gain, obesity, Diabetes, chronic diseases
If you eat too little: May lead to weight loss
Best Sources: carbohydrates in its natural form and fibre rich.

Minimize: Unhealthy sources include processed foods with refined carbs

How much to eat?

For those older than one year old, it is recommended to eat at least 130 grams (g) of carbohydrates (carbs) per day. Typically, this should make up 45-65% of your total calories for the day. Certain diets may target a lower percentage of carbs.

This recommendation is based on the average minimum amount of glucose (which is what carbohydrates break down into) needed by the brain and central nervous system. All cells use glucose for energy, but glucose is the preferred energy source for our brain. Too many carbs may also have negative health impacts.

Some carbohydrates can also be a great source of fibre.

Types of carbs – Refined vs Whole grain

There are different types of carbohydrates, which vary in quality. When we eat carbohydrates we want to choose high quality carbohydrates because they help to prevent or delay the onset of chronic disease.

Examples of higher quality carbohydrates include whole fruits and some vegetables, whole grains, and beans and legumes. They tend to take longer to break down into glucose in the body to provide energy.

Whole grains are high quality carbohydrate containing foods. They are eaten in their whole form and have not been refined (parts of the grain removed). Therefore, whole grains contain all parts: the endosperm, bran and germ. Refined grains have both the germ and bran removed during processing, which results in the removal of many nutrients such as fibre and some B vitaminsLearn more about fibre.

Increasing whole grain consumption increases our fibre intake, as well as B vitamins, iron, potassium, magnesium and folate. Research has shown that eating whole grains has been associated with a reduced risk of developing coronary heart disease and cardiovascular disease, respiratory diseases, cancer, diabetes and all-cause mortality (read more). Replacing refined grains with their whole grain counterpart, for example white bread replaced with whole grain bread, has been found to improve total blood cholesterol, lower LDL (bad) cholesterol, and improve hemoglobin A1c, which are risk factors for chronic disease.

Example grains includes whole grain versions of bread products, crackers and pasta (look at the ingredients list and look for the words ‘whole grain’), grains like rye, quinoa, oats, spelt, brown rice and popcorn (look for plain – you can always season yourself to help keep sodium down).

Many fruits and some starchy vegetables, like potatoes, corn, cassava, beets, and squash, are also good sources of good quality carbohydrates. These foods contain fibre, antioxidants, are low in calories and high in vitamins and minerals (otherwise known as nutrient dense).

Recommendations are to have half of your plate or meal to be made up of vegetables and fruit. Intake of these whole foods are associated with decreases your risk of developing cardiovascular disease, cancer and all-cause mortality. Increased intakes have also been associated with decreased risk of depression.

Beans and legumes, such as black beans, chickpeas, lentils, kidney beans, pinto beans, peas, adzuki beans, and mung beans, are complex carbohydrates that are great sources of protein, potassium, fibre, B vitamins and iron. Diets that contain beans and legumes have been found to lower blood pressure, lower total cholesterol and LDL (bad) cholesterol, and decrease risk of all-cause mortality and cardiovascular disease mortality.

Other sources of carbohydrates include confectionary (chocolate and candies), baked goods (like cookies, brownies, doughnuts, cakes and pies), sweetened beverages (pop, juice, sports drinks, energy drinks), refined grains (like white bread, pasta), and sugary breakfast cereals. These foods should be chosen less often since they tend to be higher in nutrients that we want to eat less of like added sugar, and saturated fats and low in nutrients we want to eat more of like fibre, vitamins and minerals.

Diets low in fibre and high in added sugars have been linked with an increased risk of all-cause mortality, cardiovascular disease, incidence of stroke, type 2 diabetes, and colorectal cancerRead more about added sugars hereHeart and Stroke and the CDC.

Fibre

There are two main types of fibre:

Insoluble fibre

Insoluble fibre are like sponges that absorb water, which increases the volume of your stool and helps keep you regular. It actually helps slow down digestion and can make you feel full to reduce appetite. Many insoluble fibres are fermented in the GI tract which may cause of gas.

Examples: Cereals and wheat bran, Whole-grain foods, Vegetables and fruit, Nuts and seeds, and Legumes and pulses (kidney beans, lentils, chickpeas, etc.)

Soluble fibre

Soluble fibre are important for the microbiome. They forms a gel when mixed with water which can help lower the level of cholesterol and slow down the absorption of carbohydrates.

Example: Psyllium and enriched cereals (e.g.: Kellogg’s All-Bran Buds®), Cereals and oat bran, Legumes and pulses, Fruits high in pectin (apple, orange, grapefruit, strawberrie, pear, etc.), Vegetables (eggplant, okra, asparagus, green beans and green peas, Brussel sprouts, carrots, etc.), Barley, Flaxseeds, chia seeds (source).

Glycemic Index

The glycemic index is a scale that can be used to help determine how much carbohydrate containing foods increase blood glucose in our body. This tool can be helpful for individuals who are at risk of developing, or have been diagnosed with diabetes. Choosing low glycemic index foods (GI <55) can help to prevent large spikes in blood glucose after a meal, compared to high glycemic index foods (GI >76) which are more likely to spike blood sugars. Low glycemic foods are often good sources of fibre. Glycemic index food rankings are also impacted by the fat content of a food (higher fat foods are also lower on the glycemic index scale because fat digestion slows down carbohydrate digestion), how it is cooked and the extent the food has been processed (the more processing, the more likely it will be a higher glycemic index food). Most fruits and vegetables, high fibre bran cereals, beans and legumes, dairy products and heavy whole grain breads are often low glycemic index foods, and ones that should be chosen most often. High glycemic index foods include white bread and bread products, white rice, and instant oatmeal and should be chosen less often. Some medium or high glycemic foods also have nutritional benefits, and some low glycemic index foods are not nutrient dense (a good source of vitamins and minerals) so it is recommended that you use the glycemic index as a tool with assistance from your health care provider. Low Glycemic index diets have been found to improve glycemic control, and decrease LDL (bad) blood cholesterol, and can reduce the risk of developing type 2 diabetes and cardiovascular disease.