Do we need to fear carbs?

Carbohydrates will not directly cause weight gain. No one food group can cause weight gain on its own, but rather their contribution to overall calorie intake and food quality should be considered.

Simple carbohydrates, also known as simple sugars, occur naturally in fruit, vegetables, and milk, but this also refers to table sugar (sucrose), which can be added to foods during processing.

Complex carbohydrates are starchy foods and fibres which take longer to break down and digest. These come from vegetables, legumes, wholegrains, nuts, and seeds.

Wholegrains are a type of complex carbohydrate that contains all three parts of the grain: the bran, endosperm, and germ. They are rich in fibre and nutrients, including B vitamins, vitamin E, folic acid, magnesium, iron, zinc, and selenium. Wholegrain foods include wholewheat bread, oats, barley, rye, brown rice, maize, spelt, buckwheat, and quinoa.

Refined carbohydrates are carbohydrates that have been processed to remove the bran and the germ. This means that most of the fibre and nutrients are removed. Foods made of refined carbs include white bread, white pasta, white rice, and prepackaged cakes, biscuits, and pastry products.

Carbohydrates are the body’s main source of energy ². They are broken down into simple sugars, or glucose, which enter the bloodstream and act as a fuel source for the cells in our body. When sugars enter the bloodstream, it causes a rise in blood glucose levels. Glycaemic index (GI) is a ranking system based on how quickly the body breaks down carbohydrates into glucose ³. Simple sugars are broken down quickly, causing blood glucose levels to rise quickly causing a fast – but short – boost of energy.

Complex carbs have a lower GI because digestion takes longer, the effect on blood glucose is smaller and slower and these carbs provide us with a steady source of energy over a few hours. Refined carbs raise blood glucose levels faster than wholegrains as they contain less fibre ³.

Wholegrains are high in fibre, which can’t be broken down or digested by the body. A higher fibre diet has been linked to the diversity of the gut microbiome, improved digestion, and better bowel health ^4,5. There is also strong evidence that diets high in fibre are associated with lower risk of cardiovascular disease, heart disease, stroke, type 2 diabetes, and maintenance of healthy cholesterol levels ^2,6,7. The bulk and fibre content can aid with weight management, as they make you feel fuller and more satisfied after eating ^2,6.

The Eatwell guide shows that starchy (complex) carbohydrates should make up just over a third of the food we eat, and we should choose wholegrain options wherever possible. Another third should come from fruits and vegetables, which are also a type of carbohydrate ^1,13.

The exact calorie contribution of carbohydrates will depend on the individual, but the EFSA suggests that 45% to 60% of total energy intake for adults and children over the age of 1 year should come from carbohydrates, including both simple and complex carbs ¹⁴.

It's good to know about the varying benefits of different carbohydrates, and the nutrients they can offer the body. 

Lentils are my favourite carb. There are so many different types to choose from, and they are so versatile. They have a low GI so won’t cause the blood sugar to spike and the high fibre and protein will maintain energy levels. They’re also a great source of vitamins and minerals, including iron, magnesium, and B vitamins.