How does sugar in our diet affect our health?

Eating too much sugar can make you gain weight and can also cause tooth decay.

The type of sugars most adults and children in the UK eat too much of are "free sugars".

These are:

Any sugars added to food or drinks. These include sugars in biscuits, chocolate, flavoured yoghurts, breakfast cereals and fizzy drinks. These sugars may be added at home, or by a chef or other food manufacturer.
Sugars in honey, syrups (such as maple, agave and golden), nectars (such as blossom), and unsweetened fruit juices, vegetable juices and smoothies. The sugars in these foods occur naturally but still count as free sugars.

Sugar found naturally in milk, fruit and vegetables does not count as free sugars.

We do not need to cut down on these sugars, but remember that they are included in the "total sugar" figure found on food labels.

How much sugar can we eat?

The government recommends that free sugars – sugars added to food or drinks, and sugars found naturally in honey, syrups, and unsweetened fruit and vegetable juices, smoothies and purées – should not make up more than 5% of the energy (calories) you get from food and drink each day.

This means:

Adults should have no more than 30g of free sugars a day, (roughly equivalent to 7 sugar cubes).
Children aged 7 to 10 should have no more than 24g of free sugars a day (6 sugar cubes).
Children aged 4 to 6 should have no more than 19g of free sugars a day (5 sugar cubes).
There's no guideline limit for children under the age of 4, but it's recommended they avoid sugar-sweetened drinks and food with sugar added to it. Find out more about what to feed young children.

Free sugars are found in foods such as sweets, cakes, biscuits, chocolate, and some fizzy drinks and juice drinks. These are the sugary foods we should cut down on.

For example, a can of cola can have as much as 9 cubes of sugar – more than the recommended daily limit for adults.

Find out what the top sources of free sugars are.

Sugars also occur naturally in foods such as fruit, vegetables and milk, but we don't need to cut down on these types of sugars.

Be aware that these are included along with free sugars in the "total sugars" figure that you'll see on food labels.

Find out more about nutrition labels and sugar for help on how to tell the difference.

Tips to cut down on sugars

For a healthy, balanced diet, cut down on food and drinks containing free sugars.

These tips can help you to cut down:

Reducing sugar in drinks

Instead of sugary fizzy drinks or sugary squash, go for water, lower-fat milk, or sugar-free, diet or no-added-sugar drinks. While the amount of sugar in whole and lower-fat milk is the same, choosing lower-fat milk reduces your saturated fat intake.
Even unsweetened fruit juices and smoothies are sugary, so limit the amount you have to no more than 150ml a day.
If you prefer fizzy drinks, try diluting no-added-sugar squash with sparkling water.
If you take sugar in hot drinks or add sugar to your breakfast cereal, gradually reduce the amount until you can cut it out altogether. Alternatively, switch to a sweetener.

The NHS Change4Life website has more tips to help you cut back on sugary drinks.

Reducing sugar in food

Rather than spreading high-sugar jam, marmalade, syrup, chocolate spread or honey on your toast, try a lower-fat spread, reduced-sugar jam or fruit spread, sliced banana or lower-fat cream cheese instead.
Check nutrition labels to help you pick the foods with less added sugar, or go for the reduced- or lower-sugar version.
Try reducing the sugar you use in your recipes. It works for most things except jam, meringues and ice cream.
Choose tins of fruit in juice rather than syrup.
Choose unsweetened wholegrain breakfast cereals that aren't frosted, or coated with chocolate or honey.
Choose unsweetened cereal and try adding some fruit for sweetness, which will contribute to your 5 A Day. Sliced bananas, dried fruit and berries are all good options.

The Be Food Smart app from Change4Life can help you check how much sugar you or your child is having.

Using your smartphone, the app can scan the barcode on food packets to find out exactly how much sugar is in it.

Find more ways of cutting sugar out of your diet.

Nutrition labels and sugars

Look at information on nutrition labels and ingredients lists to help reduce your intake of free sugars.

Nutrition information can be presented in different ways, including on the front and the back of packs.

Labels on the back of packaging

It's important to look for the "of which sugars" figure on nutrition labels, which is part of the carbohydrate information.

While this does not tell you the amount of free sugars, it's a useful way of comparing labels and can help you choose foods that are lower in sugar overall.

Look for the "Carbohydrates of which sugars" figure on the nutrition label.

Products are considered to either be high or low in sugar if they fall above or below the following thresholds:

high: more than 22.5g of total sugars per 100g
low: 5g or less of total sugars per 100g

If the amount of sugars per 100g is between these figures, that's regarded as a medium level.

The "of which sugars" figure describes the total amount of sugars from all sources – free sugars, plus those from milk, and those present in fruit and vegetables.

For example, plain yoghurt may contain as much as 8g per serving, but none of these are free sugars, as they all come from milk.

The same applies to an individual portion of fruit. An apple might contain around 11g of total sugar, depending on the size of the fruit selected, the variety and the stage of ripeness.

But sugar in fruit is not considered free sugars unless the fruit is juiced or puréed.

This means food containing fruit or milk will be a healthier choice than one containing lots of free sugars, even if the 2 products contain the same total amount of sugar.

You can tell if the food contains lots of added sugars by checking the ingredients list.

Sometimes you'll see a figure just for "Carbohydrate" and not for "Carbohydrate (of which sugars)".

The "Carbohydrate" figure will also include starchy carbohydrates, so you cannot use it to work out the sugar content.

In this instance, check the ingredients list to see if the food is high in added sugar.

Ingredients list

You can get an idea of whether a food is high in free sugars by looking at the ingredients list on the packaging.

Sugars added to foods and drinks must be included in the ingredients list, which always starts with the ingredient that there's the most of.

This means that if you see sugar near the top of the list, the food is likely to be high in free sugars.

Watch out for other words used to describe the sugars added to food and drinks, such as cane sugar, honey, brown sugar, high-fructose corn syrup, fruit juice concentrate/purées, corn syrup, fructose, sucrose, glucose, crystalline sucrose, nectars (such as blossom), maple and agave syrups, dextrose, maltose, molasses and treacle.

For more information on terms you might see on food label terms, such as "no added sugar", see Food labelling terms.

Labels on the front of packaging

There are labels containing nutrition information on the front of some food packaging.

This includes labels that use red, amber and green colour coding, and advice on reference intakes (RIs) of some nutrients, which can include sugar.

Labels that include colour coding allow you to see at a glance if the food has a high, medium or low amount of sugars:

red = high (more than 22.5g of sugar per 100g or more than 27g per portion)
amber = medium (more than 5g but less than or equal to 22.5g of sugar per 100g)
green = low (less than or equal to 5g of sugar per 100g)

Some labels on the front of packaging will display the amount of sugar in the food as a percentage of the RI.

RIs are guidelines for the approximate amount of particular nutrients and energy required in a day for a healthy diet.

The reference intake for total sugars is 90g a day, which includes 30g of "free sugars".

For more information, see Food labels.

Your weight and sugar

Eating too much sugar can contribute to people having too many calories, which can lead to weight gain.

Being overweight increases your risk of health problems such as heart disease, some cancers and type 2 diabetes.

For a healthy, balanced diet, we should get most of our calories from other kinds of foods, such as starchy foods (wholegrain where possible) and fruits and vegetables, and only eat foods high in free sugars occasionally or not at all.

The Eatwell Guide shows us how much of what we eat should come from each of the main food groups in order to have a healthy, balanced diet.

Learn more about how to have a balanced diet.

Tooth decay and sugar

Sugar is one of the main causes of tooth decay.

To prevent tooth decay, reduce the amount of food and drinks you have that contain free sugars – such as sweets, chocolates, cakes, biscuits, sugary breakfast cereals, jams, honey, fruit smoothies and dried fruit – and limit them to mealtimes.

The sugars found naturally in fruit and vegetables are less likely to cause tooth decay, because they are contained within the structure.

But when fruit and vegetables are juiced or blended into a smoothie, the sugars are released. Once released, these sugars can damage teeth.

Limit the amount of fruit juice and smoothies you drink to a maximum of 150ml (a small glass) in total per day, and drink it with meals to reduce the risk of tooth decay.

Squashes sweetened with sugar, fizzy drinks, soft drinks and juice drinks have no place in a child's daily diet.

If you're looking after children, swap any sugary drinks for water, lower-fat milk or sugar-free drinks.

Dried fruit and your teeth

It's better for your teeth to eat dried fruit as part of a meal, such as added to your breakfast cereal, tagines and stews, or as part of a healthy dessert – a baked apple with raisins, for example – and not as a between-meal snack.

Page last reviewed: Fri Aug 2017 Next review due: Tue Aug 2020