If you are a follower of the latest foods trending on social media, it won’t come as any great surprise that carbohydrates appear to be back on the list of foods to avoid. In a world full of ‘nutrition experts’, it can be hard to make head or tail of it all! Here are my top must know facts when it comes to carbohydrates:
Guest post by Harriet Harrex, PhD Candidate & Associate Registered Nutritionist
A carbohydrate is a nutrient, not a food
When we think about food, we often classify it by the macronutrient that it is primarily made up of – that being carbohydrate, fat or protein. For example, we may refer to bread as a carbohydrate, and chicken as a protein and peanut butter as a fat. And there lies the confusion – carbohydrates are nutrients that make up our food – not a food themselves. Carbohydrates, together with fat and protein, are found in differing levels in the foods we eat, and form the foundation of a well-balanced diet. For example, oats are high in carbohydrate but they also contains some protein and a very small amount of fat.
Biologically speaking, a carbohydrate is made up of saccharides, which are more commonly known as ‘sugars’. Glucose is a common example of a sugar in its simplest form- a monosaccharide. Two monosaccharides joined together are called disaccharides, with an example being sucrose, or ‘table-sugar’. When many saccharides (sugars), are joined together, these are called polysaccharides and are found in the foods we commonly refer to as ‘carbs’, such as bread, pasta or potato.
Focus on quality, not quantity
A lot of focus gets placed on the amount of carbohydrate we should be consuming. Guidelines from the New Zealand Ministry of Health suggest that a typical adult’s diet should be made up of 45-65% carbohydrate.But unless we sit down and look at every item of food we eat in a day and calculate the carbohydrate content, this can be really hard to understand and can leave a lot of people feeling overwhelmed. Following a very carbohydrate restrictive diet not only puts us at risk of missing out on key nutrients, but it can also leave us feeling deprived of the foods we may really enjoy.
While we all need some carbohydrate in our diets, how much we need will depend on our activity level and our health status. Some people feel better and manage their health conditions better with less carbohydrate, whereas other people do better on more carbohydrate – especially those who are really active. But rather focusing on the numbers, a focus on quality is the main thing!
By focusing on the QUALITY of the carbohydrate and overall diet, rather than the QUANTITY, suddenly our attention is shifted away from numbers which offers us with a far more positive approach to thinking about the place carbs have in our diets.
High-quality carbohydrate-rich foods include legumes (think hummus made with chickpeas, soups filled with lentils), breads and cereals with visible grains (smashed avocado on toast, warming porridge on a cold winter’s morning), quinoa (a good addition to any salad), brown rice (vege-filled stirfries), wholemeal pasta (the base of so many family-friendly meals)…. I bet you are now thinking of all the yummy meals you can prepare using these quality carbohydrate foods!
Carbohydrate rich foods are also FIBRE rich foods
Fibre is a special type of carbohydrate found only in plant-based foods, and is essential for supporting good gut health. A diet low in carbohydrate can therefore also be a diet low in fibre.
There are three different types of fibre, and each play an important role in our bodies.
- Soluble fibre – acts like a sponge- it absorbs fluid, forming a gel-like substance and makes the bowel contents softer so they can be more easily moved. Good sources of soluble fibre include oats, fruit, vegetables and legumes.
- Insoluble fibre does not dissolve in water, and acts like a bulking agent. It is found in foods such as bread, pasta and rice. Along with plenty of fluid, both types of fibre work together to keep us regular, preventing constipation.
- Resistant starch is a slightly different – it is a type of starch that isn’t fully broken down and absorbed, but rather turned into short-chain fatty acids by intestinal bacteria and used as fuel for them. It’s found in some foods such as green bananas and legumes, but it develops during the heating and cooling process of some foods, such as potato and rice. You can read more about it here
Here in New Zealand, guidelines state that females need 25g of fibre and males need 30g of fibre per day, but many of us are falling short. An easy way to increase the fibre content in our diets is by choosing wholegrain varieties of carbohydrate-rich foods, such as brown rice over white rice; ensure you get your five plus a day vegetables and fruit, and by leaving the skins on fruit and vegetables.
Carbs are for EVERYONE, not just active people
Carbohydrates are the main source of energy we need to fuel both our bodies and our brains. When we eat carbohydrates, they are broken down in our bodies to single-sugar molecules (mainly glucose) and are absorbed into the bloodstream to be used as energy. Anything that is not needed straight away is then stored in our muscles and liver as glycogen, which is ready to be used when our blood levels of glucose get too low. Once our glycogen stores are full, any excess glucose is stored as fat. That doesn’t mean carbohydrates are ‘fattening’ – excess of fat and protein are also stored as fat.
Carbs aren’t just muffins, cakes and biscuits
When we think of carbohydrates, often these foods are the first to spring to mind. While these types of carbohydrate are not very nutrient dense, there is a huge range of carbohydrates that are. Foods like fruit, vegetables, bread, cereal grains, rice, pasta, and legumes all contain carbohydrates. Even foods like milk and yoghurt contain carbohydrates!
High GI doesn’t mean high carbohydrate
You may have heard of the term ‘glycaemic index’ or ‘GI’ being used when referring to some foods. GI refers to the rate at which carbohydrates are digested in the body. In simple terms, a high GI food is more quickly digested by the body, causing a rapid rise in blood sugar levels whereas a low GI food is digested more slowly, creating a more gradual rise in blood sugar levels. However, a lot of factors can influence the GI of a food, and the subsequent effect it has in our bodies. For example, a high carbohydrate food such as a potato will have a different effect on blood sugar levels when eaten alone compared to when eaten with butter. The fat in the butter slows down the rate of digestion, creating a lower GI response, but the carbohydrate content of the potato remains the same. It is important to consider what other ingredients or nutrients the food has in it, as well as what the food is eaten with. A food classified as being ‘low’ or ‘high’ GI can also have varying effects in different people, so looking only at the GI value of a food is not really that helpful.
It’s not all about the carbs!
It’s time to stop placing so much importance on a single nutrient. When you stop and think about it, how often do we ever eat nutrients in isolation anyway? Choosing a food based purely on the carbohydrate content may mean that we overlook other qualities the food can offer us, placing us at risk of missing out on important vitamins and minerals. We need to consider the overall nutrition the food offers in the context of our whole diet. I tend to like focusing on what else the food is going to offer me, to maximise the nutritional benefit it will provide my body. Not only does this shift my thinking from a negative deprived state, but I am far more likely to make good choices that I know will provide my body with the nourishment it needs.
There is no ‘golden hour’
There seems to be some fairly strong opinions out there on when you should (or more commonly shouldn’t!) be eating carbs. No carbs with dinner, no carbs after midday, the list goes on. This can make life pretty complicated and can make social situations such as eating out pretty stressful! By including some carbohydrate based foods at every meal, our body has a steady supply of energy throughout the day and helps prevent that dreaded 3pm energy slump. You are far, far better off allowing yourself a serve of carbohydrate with each meal than to reach the end of the day and devour a packet of biscuits because you feel so low in energy.
So as you can see, there are many things to consider when thinking about carbohydrates. They really aren’t the evil monster that they get so commonly made out to be! Thinking about the quality of the carbohydrate and the other nutrients a food has to offer is a good place to start, and really does help simplify the complex task eating has become.
Harriet is a PhD Candidate in the Dunedin School of Medicine at Otago University. Her primary area of interest lies in how behaviours at an early age are related to health and behaviour later in life, and intends to use her learning in both sleep and nutrition to pursue a career that involves both disciplines in future research and teaching. She is Committee Secretary for the Postgraduate and Early Career Nutrition Conference and an Associate Registered Nutritionist with the Nutrition Society of New Zealand. You can check her out on LinkedIn here.