Understanding sugar in the diet

Sugar is often in the headlines when it comes to nutrition and has been described as toxic, addictive and responsible for obesity, type 2 diabetes and other illnesses. But what are the facts about sugar? 

What are sugars?

Sugar is a simple carbohydrate. Although we may think of ‘sugar’ as one thing there are several types of sugars. Glucose and fructose joined together make sucrose, which is what we normally call ‘sugar’, used for baking or putting in tea or coffee. Other sugars include lactose (naturally present in milk) and maltose (found in cereal grains). Sugars can come in different forms; they can be naturally occurring like in fruit and milk, or they can be added and used as an ingredient in different foods and drinks. There is agreement that the type of sugars that we should be eating less of in our diets is ‘free sugars’.

But when fruit and vegetables are juiced the sugars are released from the structure of the food. It has been suggested that sugars such as those in juices and smoothies can be consumed more easily in much greater quantities than sugars present within structures that have not been broken down. 

In other words, we can drink a glass of juice or smoothie much quicker than the time it would take us to eat the number of whole fruits and vegetables it took to make it, and this could lead to overconsumption of calories and sugars.

How does a high intake of sugars affect our health?

The government recommends that free sugars make up no more than 5% of daily calorie intake. What this is equal to for different age groups can be seen on the right.

On average we are consuming between 9% and 12.5% of our calories from free sugars, depending on the age group. So, although our intakes of free sugars have decreased in recent years, we are still consuming quite a lot more than is recommended.

Children aged 4-10 years

Children aged 11-18 years

Adults aged 19-64 years

The charts above show the contribution of different food groups to free sugars intake at different ages. We can see that the foods and drinks that contribute the most is different at different ages, with sugary soft drinks making the biggest contribution for 11-18 year olds. Biscuits, buns, cakes, pastries and fruit pies are the biggest single contributor for adults but together, sugary soft drinks and alcoholic contribute the most to free sugars intake.

Sugary drinks have been a big focus when it comes to reducing sugar intakes as they tend to contribute sugar, but few essential nutrients and we can make a straightforward swap to water or sugar free drinks instead. Since 2016 in the UK we have had the ‘soft drinks industry levy’ (a ‘sugar tax’ on companies making soft drinks), which taxes drinks with added sugars. This means that a lot of soft drinks such as fizzy drinks or squashes now have less or no sugar. Look out for options with no added sugar and go for these where possible.

When it comes to the health effects of free sugars, the main concerns are dental health, calorie intake and bodyweight.

Sugar is one of the main causes of tooth decay and so to reduce our risk it is important to reduce the amount of foods and drinks containing free sugars we consume, and if we do have them, to limit them to mealtimes.

Sugary foods and drinks can also have large amounts of calories, and so having them too often and in large quantities can lead to weight gain and obesity, which in turn could increase the risk of heart disease and type 2 diabetes. Because of these effects of sugar on our health, the government has taken steps to try to reduce our sugar intakes, including the tax on soft drinks and work with the food industry to reduce the sugar content of sweet foods.

Which foods and drinks have free sugars?

Free sugars are found in:

• Sugary drinks, including fizzy drinks and energy drinks, which may be sweetened only with sugar or a combination of sugars and sweeteners.
• Fruit drinks, juices and smoothies have some vitamins and minerals and natural sugars, but these are still classed as free sugars and it is best to keep these to one small glass (150ml) a day.
• Sweet foods like biscuits, cakes, pastries, chocolate, desserts and sweets are made with some kind of sugar, whether that is table sugar (sucrose), fruit purees, syrups or honey.
• Honey and syrups like maple syrup or agave nectar – even though these may be natural, they still have free sugars.
• Fruit and flavoured yogurts have some natural sugars from milk or fruit and may also have some sugars added.

Sugars on the label

There are different things you can look out for on food and drink labels to find out about their sugar content.

Total sugars on the nutrition label

‘Total sugars’ includes both free and intrinsic sugars. If a food or drinks product has a label on the front-of-pack it will show you the amount of total sugars per 100g or per portion of the product and will also be colour coded red, amber or green with the words ‘high’, ‘medium’ or ‘low’. You can also find the amount of ‘total sugars’ in the nutrition information on the back-of-pack.

Sugars in the list of ingredients

Sugars added to a product must be included in the list of ingredients.

Free sugars may appear in the ingredients list as ‘sugar’ but other words and terms to look for include: 

Ingredients are listed in descending order of weight, so if a type of sugar appears near the beginning of the ingredients list, the product is likely to have more free sugars than one in which added sugars are at the end.

How can I eat less sugar?

Many of us are trying to eat less sugar. The main sources of free sugars in the UK diet are sugary drinks (sugary fizzy drinks, energy drinks, sugary squashes and cordials) and fruit juice, cakes, biscuits, desserts, sweet spreads and confectionery. Reducing these foods and drinks in our diet may help us reduce our free sugars intake.

Some things you could try are:

• Swap sugary drinks for sugar-free versions or water.
• Swap sweet snacks for fresh fruit or something savoury like wholegrain crackers with cheese.
• If you include sweet foods like cakes, chocolate, biscuits or desserts in your diet try cutting down your portion sizes.
• Try natural yogurt with fruit instead of yogurts with added sugar.
• Check labels when choosing breakfast cereals and go for those with less sugar.
• Swap jams or chocolate spreads for lower sugar nut butters.
• Keep fruit juices or smoothies to one small glass (150ml) per day.

Overall, having a healthy, balanced diet can help us keep our intakes of free sugars down because this kind of diet includes more of the healthier choices that provide us with fibre, vitamins and minerals and fewer foods and drinks that are high in free sugars. It is a good idea to reduce our sugar intakes, but also to think about what we can eat more of, such as fruit, vegetables, pulses and wholegrains. Find out more by reading our pages on a healthy, balanced diet.

What about 'hidden' sugars?

All packaged products must provide nutrition information and a list of ingredients, so strictly speaking sugars can’t be ‘hidden’ as they must be listed on pack. But you may find that sugars are sometimes added to products that you do not think of as ‘sweet’ such as ready-made sauces or salad dressings. For example, sugar is sometimes added in a tomato-based sauce to counter the acidity of the tomatoes. Sugar also features an ingredient in some homemade sauce recipes for the same reason.  Savoury foods do not appear to be making a significant contribution to our free sugars intake, which mainly comes from sweet foods and drinks.  But, when you are choosing products, it is a good idea to go for those with less sugar most of the time or you could try making things like pasta sauce yourself so that you can control how much (if any) sugar is added.

For more information on the sources used in this text please contact postbox@nutrition.org.uk

Last reviewed June 2021. Next review due June 2024.