Along with fat and protein, carbohydrates are one of the three food groups essential to human health. A healthy, balanced and varied diet is one that includes a combination of these food groups in the diet in adequate amounts, and the right quality of these goods, too. Yet carbohydrates have been at the centre of one of the most heated debates in nutrition history, creating much misunderstanding and uncertainty. So why we are so confused about carbohydrates?
Why are carbohydrates important?
Carbohydrates are the body’s first choice as a source of energy. The brain, nervous system and red blood cells exclusively use glucose (the breakdown product of carbohydrates) for energy, making some carbohydrates vital as part of our diet. From a nutrient point of view, carbohydrates contain thiamine, folate, magnesium, potassium, and vitamins A, E and B6. Carbohydrate-rich foods are also the biggest source of fibre in our diets. Whole grain, high fibre carbohydrates help maintain a healthy gut to decrease risk of diabetes, cancer, stroke and heart disease, and even obesity.
What foods contain carbohydrates?
“Everything from lentils to lollipops contains carbohydrates,” says prominent nutrition researcher Dr David Katz. Carbohydrate foods include fruit, vegetables and grains, less obvious sources like legumes and dairy, and, of course, sugar. The modern diet that is high in refined carbohydrates and simple sugars is of course not ideal for our health. But it is short-sighted to treat the vast range of foods containing carbohydrates as one all-inclusive food group. For example, sugar is part of the carbohydrate group with very little nutritional value and a lot of energy. Excess amounts of highly refined carbohydrates, sugar, and sugar containing foods and drinks are certainly not ideal for our health. These foods cause a quick spike in blood glucose, triggering a host of metabolic changes in the body like kickstarting the inflammatory processes that cause chronic disease, and impacting heart disease, diabetes, and overall health.
On the other hand, fruit is also a carbohydrate. Fruits (and vegetables) are rich in healthy nutrients like vitamins A and C, folate and potassium, contain gut-healthy fibre, are low in energy, and are virtually free from poor nutrients like cholesterol, sugar, sodium and saturated fat. This is part of why a diet that includes fruit can help manage our weight, lower blood pressure, reduce the risk of heart disease, stroke and some cancers, and improve gut health. In fact, low intakes of fruit have been linked to over 520 000 heart disease deaths and more than 1.2 million stroke deaths globally each year.
For these reasons, it we cannot compare ordinary table sugar and nutrient-packed whole fruit in the same light. Aim to include an unlimited variety of vegetables in your daily diet such as broccoli, cauliflower, carrots, cucumber, pumpkin, gem squash and beetroot, and no more than two and three fist-sized servings of fruit per day The focus should be on complex, minimally processed carbohydrates in the diet (e.g. wholegrain high fibre bread, brown rice, wholewheat pasta, oats), while keeping sugar and sugary treats for special occasions only.
Is it a good idea to not eat any carbs?
A diet that includes less than 40% of its total energy from carbohydrates is considered a low carbohydrate diet. Some popular low carb diets, like a ketogenic diet, are even more strict with carbs as low as 5% of total energy, a huge challenge. Less than 25g of carb per day (another way to classify a low carb diet) is the equivalent of eating one medium-sized apple. Including any more carbs in your day, whether from fruit, vegetables, milk in tea or coffee, legumes or wholegrains would mean you have used up your carbs for the day. This is why it becomes very difficult to include a varied, nutrient- and fibre-rich diet when cutting carbs in the diet as nutrients like the B vitamins thiamine, B6 and folate, minerals like magnesium and potassium, and vitamin A and E may be missing. Many carb-containing foods like fruit, vegetables, wholegrains and legumes offer a host of benefits for our health including constipation-preventing, cancer-killing, heart-disease-risk-lowering, energy-rich, and inflammation-blocking phytonutrients, polyphenols, minerals, vitamins, and antioxidants. Carbohydrate foods are also generally rich in fibre, so it becomes very difficult to include fibre for good gut health on a low carb diet. Without eating fibre form whole grain foods, fresh vegetables, legumes and fruit, it becomes difficult to meet your fibre needs which may cause gut troubles like bloating and constipation, diverticular disease, and increased risk for colon cancer.
Can I eat carbs and still lose weight?
Despite all the media attention, a South African study led by Dr Celeste Naude from the Centre for Evidence-based Healthcare in Stellenbosch combined the findings of 19 clinical trials on more than 3 000 participants to show that low carbohydrate diets are not more effective for weight loss in comparison to a balanced, kilojoule-reduced diet. On a low carb diet, there is no denying that weight loss occurs but this is purely because the person cuts total calories from removing carbs, not because they have cut carbs per se. successful weight loss goes beyond cutting out entire food groups: it is a complex interaction of metabolic processes, physical activity, and genetics. The kilos will drop on any energy-controlled eating plan, whether the diet is low carb or not. Successful weight loss requires cutting your energy intake from food and drinks to create a significant energy shortage.
It is clear that not all carbs are created equal. Treating the expanse of foods containing carbohydrates as one all-inclusive food group is short-sighted. Just like fat, there are carbohydrate-containing foods that are not as healthy as other highly nutritious versions. Focus should be less on refined sugary carbs and more on high fiber, slow release carbohydrates such as fruit, starchy vegetables, and legumes. High quality carbs promote health and wellness by offering sustained energy for the busy work days, improving gut health, reducing cardiovascular disease and diabetes risk, and increasing disease-preventing phytonutrients and fibre in the diet. When selecting carbs, simply choose wisely. Be sure to curb the carbs that do not count, but keep the nutrient-packed great carbs that do add to our health.
Written by Monique Piderit, Registered dietician