Updated: Nov 26, 2020
This is the first of the 3-part macronutrient series, where we will set the scene for carbohydrates, fats and protein in our diet.
In this first part, we will discuss all about carbohydrates, learning about the various types of carbohydrates and how to incorporate them into our diet!
Carbohydrates are the body’s primary source of fuel. In the body, carbohydrates are broken down into glucose (sugar) to be used as a source of energy to help fuel our day and energise both our brains and muscles.
Carbohydrates are made up of sugar, starch, and fibre. Therefore, any food composed of sugar, starch or fibre is considered a carbohydrate, and this includes everything from fruits and vegetables, to potatoes and grains.
Today, the term carbohydrate is generally used to refer to starchy foods such as grain-based bread, pasta and cereals; root vegetables like potatoes, carrots, parsnips, beets; and sugars. However, all vegetables are sources of complex carbs, so even when you cut out starchy carbs, you are never ‘carb-free’, unless you also cut out all vegetables and fruit.
So let’s break it down…
What are simple carbohydrates?
Simple carbs are refined grains that are milled; a process that strips out both the bran and germ to give them a finer texture and longer shelf life. The refining process also removes many nutrients, including fibre.
Simple carbohydrates are easily and quickly utilised for energy by the body due to their simple chemical structure (composed of only one or two sugars). This often leads to a faster rise in blood sugar levels and insulin secretion from the pancreas. These foods create blood sugar imbalances which is the reason why you may feel hungry again soon after consumption.
Simply put, simple carbs are just simple sugars.
Examples of simple carbs include: sugars (white, brown and raw), white flour, pastries, donuts, croissants, cookies, fruit juice concentrate and breakfast cereal.
What about complex carbohydrates?
These carbohydrates have more complex chemical structures (with three or more sugars linked together). Many complex carbohydrate foods contain fibre, vitamins and minerals, and they take longer to digest – which means they have less of an immediate impact on blood sugar, causing it to rise more slowly and steadily.
Complex carbohydrates can be divided into sub-categories:
1. Whole grains; such as: whole wheat flours, whole wheat bread, oats (porridge), quinoa, brown, red and wild rice, bulgur wheat, freekah, whole barley, rye, spelt, and even popcorn (plain).
2. Starchy vegetables; such as: sweet potatoes, carrots, beets, pumpkin and squash.
3. Other vegetables; such as: green leafy vegetables, onions, tomatoes, peppers.
4. Fruit; such as: dates, berries, apples, plums, pears, bananas.
What makes whole grains, whole?
Whole grains contain the endosperm, germ, and bran, in contrast with refined grains, which have the germ and bran removed. Whole grains are good sources of fibre, B vitamins, and some trace minerals such as iron, magnesium, and zinc (1).
Those nutrients are found in the outer layer of the grains that function as a protective shell for the germ and endosperm inside. The germ is nourishment for the seed and contains antioxidants, vitamin E, and some B vitamins, while the endosperm provides carbohydrates, protein, and energy.
What are the health benefits of complex carbs in our diet?
Reduced risk of cardiovascular diseases (heart diseases and stroke)
A high intake of whole grains is associated with reduced risk of coronary heart disease, ischaemic stroke, total cardiovascular disease, and several cancers, as well as risk of death from all causes. (2),(3)
Type 2 Diabetes
Complex carbohydrates can help people with type 2 diabetes as they manage blood sugar spikes after meals.(4),(5)
Fibre and starch are the two types of complex carbohydrates. Fibre is especially important because it promotes bowel regularity and helps to control cholesterol.(4),(5)
Optimises Gut Health
Consuming adequate amounts of fibre optimises the function of the good bacteria in the gut.(6)
Practical and simple tips to increase your complex carb intake:
Instead of cereal, have porridge oats for breakfast, or even make your own homemade granola.
Swap white rice for brown rice at dinner.
Include sweet potatoes in your lunches and dinner.
Make a big batch of quinoa so you can make quinoa salad for lunch and include it in your porridge in the morning.
Swap white flours for whole wheat flours or spelt flour in your desserts.
Add whole barely to your soups and stews at dinner.
Opt for eating whole fruits rather than fruit juice as whole fruits contain more dietary fibre.
Snack on plain popcorn, or oat cakes, or rye crackers, while adding your favourite toppings e.g. hummus, peanut butter or even make your own chia seed jam!
Bottom line: Carbohydrates are a major macronutrient needed for the body and are the primary source of energy. The goal is simply to keep your body fuelled in proportion to your level of activity. The key is not avoiding carbohydrates completely but finding the RIGHT carbs.
Quality, not quantity is what matters most.
1) Slavin JL, Jacobs D, Marquart L, Wiemer K. The role of whole grains in disease prevention. J Am Diet Assoc2001;101:780-5. doi:10.1016/S0002-8223(01)00194-8 pmid:11478475.
2) Aune Dagfinn, Keum NaNa, Giovannucci Edward, Fadnes Lars T, Boffetta Paolo, Greenwood Darren C et al. (2016). Whole grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-response meta-analysis of prospective studies BMJ 353 :i2716. [Available from: https://www.bmj.com/content/353/bmj.i2716]
3) Geng Zong, Alisa Gao, Frank B. Hu, and Qi Sun. (2016). Whole Grain Intake and Mortality From All Causes, Cardiovascular Disease, and Cancer. Circulation. 2016;133:2370–2380. [Available from: https://www.ahajournals.org/doi/abs/10.1161/CIRCULATIONAHA.115.021101]
4) Ludwig David S, Hu Frank B, Tappy Luc, Brand-Miller Jennie. (2018). Dietary carbohydrates: role of quality and quantity in chronic disease. BMJ; 361 :k2340 [Available from: https://www.bmj.com/content/361/bmj.k2340].
5) Forouhi Nita G, Misra Anoop, Mohan Viswanathan, Taylor Roy, Yancy William. (2018). Dietary and nutritional approaches for prevention and management of type 2 diabetes BMJ. 361 :k2234 [Available from: https://www.bmj.com/content/361/bmj.k2234]
6) Makki K, Deehan EC, Walter J, Bäckhed F. (2018). The Impact of Dietary Fiber on Gut Microbiota in Host Health and Disease. Cell Host Microbe. 13;23(6):705-715. [Available from: https://www.ncbi.nlm.nih.gov/pubmed/29902436]