Carbohydrates

Carbohydrates are an important nutrient we use for fuel. Foods containing carbohydrates form part of a healthy, balanced diet for many people. There are lots of confusing messages about foods containing carbohydrate. Foods that contain carbohydrate provide us with energy, vitamins, minerals and fibre which are important for health. 

Carbohydrates are the nutrients in food that are broken down into glucose, a source of fuel for the body. Carbohydrate containing foods can be divided into the following categories:

• Foods high in complex or less processed starchy carbohydrates which tend to break down into glucose more slowly (e.g. wholegrain bread, wholegrain rice). 
• Foods containing natural sugars such as fruit, milk and yoghurt.
• Free sugars. Foods high in free sugars will turn into glucose quickly (e.g. sweets, sugar, honey). We try and minimise free sugars in the diet where possible.
  • Note: Naturally occurring sugars e.g. lactose or fructose do not count as free sugars if they remain in the food (e.g. an apple does not count as free sugars, but will be treated as free sugar if removed from the food e.g. apple juice)
• Dietary fibre. Foods rich in dietary fibre promote digestive health. They are often found alongside in foods that contain complex / starchy carbohydrates as well as fruit and vegetables.

Can low carbohydrate diets help manage weight?

All food including those containing carbohydrates contains energy. Although we may need less energy and carbohydrate if we are less active, they remain an important source of energy and a key food group for health.

Any dietary restriction can lead to weight loss, but weight loss is not always the same as fat loss. The fluid and weight changes that are seen during rapid weight loss are not necessarily related to health or wellbeing. As with any dietary restriction, a diet very low in carbohydrate will be lower in food volume and may have less dietary fibre. Embarking on a low carbohydrate diet without adequate planning and support, could affect gut health and lead to constipation. 

Some people find that adjusting carbohydrates is an effective way to manage their weight, whilst others may find that any dietary restriction (including carbohydrate restriction) exacerbates cravings or is unsustainable. 

In general, it is a good idea to be aware of portion sizes of all foods including carbohydrate. It is important to realise that looking after our weight is complicated, and restricting any one food group (including carbohydrate) is generally not recommended for many reasons including the physical and psychological consequences of restriction. A registered dietitian can support your individual health needs. 

How much carbohydrate should we eat? 

This is a question that confuses so many people. Whilst ‘very low carbohydrate diets’ are not generally recommended, as a nation our portion sizes have increased dramatically over the past 40 years. For many of us, we should try to be ‘carbohydrate aware’. This means aiming to have appropriate portions of ‘foods containing starchy carbohydrate’, choose less high sugar and processed foods, and opt for wholegrain options where possible. 

As a general rule, a portion about the size of your fist is an appropriate mealtime portion of carbohydrate-containing foods. This can then be adjusted depending on your activity levels. Current recommendations suggest we can balance our portions this way to so that half of our energy intake comes from carbohydrate.

Free sugars

Free sugars are any sugars added to food (e.g. biscuits, chocolate, cake) or sugars naturally present in honey, syrups and fruit juices. These are associated with poor dental health, and poorer cardiovascular outcomes. There is a lot of media and public interest in ‘sugar’ and the sugar debate can be very confusing as sugar can be found in many foods. Current recommendations have suggested that it is important to be aware of ‘free sugars’ and to limit our intake of these. It is recommended that adults consume no more than 30g free sugar (approximately seven teaspoons) per day. Find out more in our Sugar fact sheet.

Where are free sugars found?

Table sugar, syrup, treacles, honeys, coconut sugar and fruit juice are all examples of free sugars. 

What does not count as free sugar? 

Natural sugars found in milk, whole fruit and vegetables. In their natural forms the glucose found within the structure of plants will release glucose more slowly and contain fibre to slow the absorption.

Summary 

• Carbohydrates are broken down into glucose which is used to fuel our bodies.
• Foods that contain carbohydrates are an important part of our diets and can be included in as part of a healthy balanced diet. Choose wholegrain options where possible. 
• Choose the correct portion to suit your own energy needs.
• Be aware that foods high in ‘free sugars’ often provide lots of energy with very little nutritional value so these should be consumed in moderation. 
• If you’re thinking of starting a low carbohydrate diet, consult your GP or dietitian.