Sugar and Free Sugars: What They Are and How Much Is Too Much

What are free sugars?

The term "free sugars" was introduced by SACN in its 2015 Carbohydrates and Health report and adopted by the UK government as the standard for dietary sugar recommendations. It replaced an older term, "non-milk extrinsic sugars" (NMES), and is closely aligned with the WHO's definition of "free sugars" published the same year.

The formal definition

Free sugars are all monosaccharides and disaccharides added to foods by the manufacturer, cook, or consumer, plus sugars naturally present in honey, syrups, and unsweetened fruit juices and smoothies.

In plain English, free sugars are:

• Any sugar added to a food or drink. Whether by the manufacturer in the factory, by a chef in a restaurant, or by you at home. This includes table sugar (sucrose), glucose, fructose, dextrose, maltose, and any other sugar used as an ingredient.
• The sugars in honey, syrups, and nectars. Including maple syrup, agave nectar, golden syrup, rice syrup, date syrup, and similar. These are often perceived as "healthier" than refined sugar, but under the SACN definition they count as free sugars because the sugars are no longer enclosed within a food's cell structure.
• The sugars in fruit juices, vegetable juices, and smoothies. Including 100% unsweetened juice. When fruit is juiced or blended into a smoothie, the cellular structure is broken down and the sugars are released into solution, where they behave like added sugar.

What is NOT a free sugar

• Sugars naturally present inside whole fruit and vegetables. As long as the cellular structure is intact (i.e., you are eating the fruit or vegetable rather than juicing it). Whole fruit counts towards your five-a-day target and its sugars do not count towards the free sugars limit. See the fruit encyclopedia for individual fruit nutrition.
• Lactose in milk and plain dairy products. The naturally occurring sugar in milk is excluded from the free sugars definition.
• Sugars naturally present in whole grains, nuts, and seeds. These are enclosed within cell structures and are excluded.

This distinction matters enormously for how you interpret food. An apple contains around 10g of sugar, but none of it is a free sugar. A glass of apple juice contains a similar amount of sugar, but all of it is a free sugar, because the juicing process has broken down the cellular structure. A flavoured yogurt containing 15g of sugar may have some lactose (not a free sugar) and some added sugar (a free sugar). The label will not always make this easy to separate.

The UK recommendations

The 5% target

SACN recommends that free sugars should account for no more than 5% of total daily energy intake for adults and children aged two and over. This was halved from the previous 10% recommendation following the 2015 review of the evidence.

In practical terms:

• Adults: no more than 30g of free sugars per day (approximately 7 teaspoons)
• Children aged 7 to 10: no more than 24g per day (6 teaspoons)
• Children aged 4 to 6: no more than 19g per day (5 teaspoons)
• Children under 4: free sugars should be avoided as much as possible

Where the UK population actually sits

Data from the National Diet and Nutrition Survey (NDNS), Years 9 to 11 (2016/2017 to 2018/2019), shows that every age group in the UK exceeds the recommendation:

• Adults aged 19 to 64: average free sugar intake equivalent to around 9.9% of daily energy, approximately double the target
• Adults aged 65 and over: around 9.4% of daily energy
• Children aged 4 to 10: around 12.1% of daily energy
• Children aged 11 to 18: around 12.3% of daily energy, more than double the target, equivalent to around 70g of free sugars per day in late adolescence

Intake has fallen over the past decade, partly due to reformulation programmes and the Soft Drinks Industry Levy (the "sugar tax") introduced in April 2018. A 2024 study by researchers from Cambridge, Bath, and Oxford found that in the year after the levy came into force, children's free sugar intake from food and drink fell by around 5g per day and adults' by around 11g per day, with over half of the total reduction coming from soft drinks alone. But average intakes remain well above the 5% target across all groups.

The 90g total sugars figure

You will sometimes see "90g" cited as a reference intake for total sugars on UK food labels. This is not the same as the free sugars limit. Total sugars includes all sugars: free sugars plus naturally occurring lactose in dairy and intrinsic sugars in whole fruit and vegetables. The 30g free sugars limit is the more meaningful figure for health purposes and is the one referenced throughout this page.

Where free sugars come from. The hidden sources

Most people know that sweets, chocolate, fizzy drinks, and cakes contain sugar. What surprises many people is how much free sugar is present in everyday foods that do not taste particularly sweet, and in products often perceived as healthy.

Two more places worth knowing about. Bread: many mass-produced sliced loaves contain added sugar (typically 2 to 4g per two slices). Artisan sourdoughs and bread made from flour, water, yeast, and salt only typically contain less than 1g per two slices. Ready meals: many supermarket ready meals contain added sugar as a flavour enhancer, even in savoury dishes like curries, stir-fries, and pasta bakes. Checking the ingredient list is the only way to know.

Sugar-sweetened drinks remain the largest single source of free sugars, particularly for children and teenagers. They provide around 17% of the free sugars consumed by 11 to 18 year-olds. The Soft Drinks Industry Levy has driven significant reformulation, and sugar content in soft drinks fell by approximately 30% following the levy. But high-sugar drinks remain widely consumed.

For the broader pattern (why so much UK food is heavily sweetened in the first place), see the article on ultra-processed foods.

What too much free sugar does to the body

The evidence for harm from excessive free sugar consumption has strengthened considerably over the past decade. A 2023 BMJ umbrella review (Huang et al.) of 73 meta-analyses covering over 8,600 individual studies found significant harmful associations between dietary sugar consumption and 45 health outcomes across cardiovascular, metabolic, dental, neuropsychiatric, hepatic, and respiratory categories.

Obesity and weight gain

Free sugars, particularly in liquid form, contribute to excess calorie intake in ways that solid food does not. Sugary drinks deliver calories without triggering the satiety hormones that solid food stimulates. You can drink 35g of sugar in a can of cola in under two minutes without feeling meaningfully fuller.

The SACN review confirmed the link between sugar-sweetened beverage consumption and weight gain and higher BMI in children and adults. Drinking high-sugar beverages results in weight gain and increases in BMI, particularly in children and teenagers.

The mechanism is partly caloric (liquid sugar is easy to overconsume) and partly hormonal. High-sugar foods, particularly those with a high glycaemic index, cause rapid spikes in blood glucose, followed by insulin surges, followed by a rapid fall in blood glucose that can trigger hunger sooner than a lower-sugar meal would.

Type 2 diabetes

Sugar-sweetened beverage consumption is one of the most consistently replicated dietary risk factors for type 2 diabetes in large prospective cohort studies. Each 250ml per day increment of sugar-sweetened beverage consumption has been associated in meta-analyses with a 17% higher risk of coronary heart disease and a 4% higher risk of all-cause mortality.

The link between free sugars and type 2 diabetes is partly mediated through obesity (excess weight is the strongest modifiable risk factor for type 2 diabetes) and partly through the direct effects of repeated high blood glucose spikes on insulin sensitivity over time.

A 2023 modelling study estimated that a gradual sugar reduction programme targeting soft drinks could prevent around 300,000 cases of type 2 diabetes over 20 years in the UK.

Dental decay (caries)

Tooth decay is the most common chronic disease in children in the UK, and dental extractions remain one of the most frequent reasons for hospital admissions in young children in England. Free sugars are the primary dietary cause.

The mechanism is direct: bacteria in the mouth metabolise free sugars and produce acid. This acid demineralises the enamel surface of teeth. Repeated sugar exposure throughout the day gives enamel insufficient time to remineralise, leading to progressive decay.

Crucially, the risk comes from frequency of exposure as much as quantity. Sipping sugary drinks throughout the day is more damaging to teeth than consuming the same amount of sugar in one sitting with meals. This is why dentists and SACN both advise limiting free sugars (particularly drinks) to mealtimes where possible.

Whole fruit, despite containing sugar, poses much lower risk to teeth because the sugars are enclosed within cell structures. Juice and dried fruit pose higher risk because the sugars are more freely available and sticky.

Cardiovascular disease

The link between free sugars and cardiovascular disease is primarily, though not exclusively, mediated through obesity and type 2 diabetes, which are themselves major cardiovascular risk factors. However, some research suggests more direct mechanisms.

A 2014 JAMA Internal Medicine study found that people whose diets provided 17 to 21% of calories from added sugar had a 38% higher risk of dying from cardiovascular disease compared to those getting 8% of calories from added sugar. Sugar-sweetened beverage consumption has been independently associated with higher triglyceride levels and lower HDL cholesterol in multiple studies, both unfavourable cardiovascular markers.

Fructose specifically (present in table sugar, high-fructose corn syrup, and many fruit juices) is metabolised primarily in the liver rather than muscles, and high fructose intake has been associated with non-alcoholic fatty liver disease and elevated triglycerides.

Mental health and mood

Evidence for a direct link between free sugar consumption and mental health is less established than the metabolic links, but is accumulating. The 2023 BMJ umbrella review found significant harmful associations between sugar consumption and neuropsychiatric outcomes. High sugar diets have been associated with higher rates of depression in several large observational studies.

Proposed mechanisms include the inflammatory effects of excess free sugar consumption, the impact of blood sugar volatility on mood and energy, and the indirect effects through obesity and metabolic disruption. All of which are associated with poor mental health outcomes.

There is also a well-documented short-term pattern: high-sugar foods can cause a rapid energy rise followed by a blood sugar crash, which some people experience as fatigue, irritability, or difficulty concentrating in the hours after eating.

Liver health

The liver is the primary site of fructose metabolism. When fructose arrives at the liver in large quantities, as it does with regular consumption of sugary drinks, which deliver fructose rapidly and in liquid form, it is converted to fat. This is associated with non-alcoholic fatty liver disease (now also termed metabolic dysfunction-associated steatotic liver disease), a condition that is rising sharply in prevalence in the UK and is closely linked to high sugar and ultra-processed food consumption.

What about natural sugars? The fruit question

This is the most common area of confusion around sugar, and it is worth addressing directly.

Does whole fruit count as a free sugar?

No. Whole fruit contains sugars (fructose primarily) but these sugars are enclosed within the cell walls of the fruit. When you eat an apple, the fibre slows digestion and the sugar is released gradually into the bloodstream. You also feel full because of the fibre and water content. The sugars in whole fruit do not count towards the SACN free sugars limit, and the NHS explicitly does not recommend reducing whole fruit intake.

Large epidemiological studies consistently show that higher whole fruit consumption is associated with lower (not higher) risk of type 2 diabetes, cardiovascular disease, and overall mortality. The same is not consistently true of fruit juice. See fruit and the evidence for health benefits for the detail.

Is fruit juice a free sugar?

Yes. When fruit is juiced, the cellular structure is broken down and the fibrous matrix is largely removed. The sugars enter your bloodstream more quickly, without the fibre-mediated slowing. A 250ml glass of orange juice contains around 22g of sugar. By volume, that is similar to Coca-Cola. The NHS recommends limiting fruit juice to one small glass (150ml) per day, counted as one portion of your five-a-day regardless of how much you drink.

What about dried fruit?

Dried fruit retains some fibre but is very calorie-dense and the sugars are concentrated. It also tends to be sticky, which increases the risk of dental decay. NHS guidance counts a 30g portion of dried fruit as one of your five-a-day. It is nutritionally better than confectionery but not equivalent to whole fresh fruit.

Is honey a free sugar? What about maple syrup or agave?

Yes. Honey, maple syrup, agave nectar, date syrup, coconut sugar, and other "natural" sweeteners are all free sugars under SACN's definition. They contain trace amounts of minerals or beneficial compounds, but in the quantities typically consumed these are nutritionally insignificant. They count towards your 30g daily limit in the same way as table sugar. They are not a health food in any meaningful sense, despite frequent marketing suggesting otherwise.

How to spot sugar on a food label

Sugar appears under many names on UK ingredient lists. Manufacturers are legally required to list all ingredients, but "sugar" can be listed under any of its alternative names, which can make the true sugar content harder to assess than it should be.

All of these count as free sugars and add to your 30g daily limit. Ingredients are listed in order of weight. If any of these appear near the top of an ingredient list, the product is likely high in free sugars.

Reading the nutrition label

The "Sugars" figure on the nutrition panel shows total sugars: free sugars plus naturally occurring sugars. For products containing dairy or whole fruit, some of that figure will be naturally occurring lactose or intrinsic sugars. For products with no dairy or whole fruit (confectionery, drinks, sauces, cereals), virtually all of the "Sugars" figure will be free sugars.

The traffic light system on UK labels uses these thresholds:

• Red (high): more than 22.5g of sugar per 100g, or more than 11.25g per 100ml for drinks
• Amber (medium): 5 to 22.5g per 100g
• Green (low): 5g or less per 100g, or 2.5g or less per 100ml

Practical steps to reduce free sugars

The goal is not to avoid all sugar or to stress about every gram. The aim is to close the gap between the UK average (roughly double the target) and the SACN recommendation of 30g per day for adults. Most people can do this through a handful of consistent changes without overhauling their entire diet.

1. Rethink drinks first. Drinks are the fastest route to excess free sugars. A single can of regular cola, a shop-bought smoothie, or a large flavoured coffee can each exceed the adult daily limit on their own. Switching sugary drinks to water, plain sparkling water, plain tea, or plain coffee makes a larger difference than almost any other single change. Limiting fruit juice to a 150ml glass per day is a meaningful step for those who drink it regularly.
2. Check your breakfast. Many popular breakfast cereals are high in free sugars. Plain oats, plain Weetabix, and plain Shredded Wheat are low-sugar alternatives. Switching from flavoured yogurt to plain whole milk yogurt and adding your own fresh fruit removes significant free sugars from a daily habit without sacrificing nutrition.
3. Read the ingredient list, not just the traffic light. A product can have an amber traffic light for sugar but still contain significant free sugars. Check the ingredient list for any of the sugar names listed above. If sugar or a sugar synonym appears in the first three or four ingredients, it is present in meaningful quantities.
4. Make sauces from scratch where you can. Jarred pasta sauces, ketchup, barbeque sauce, and sweet chilli sauce are consistent sources of free sugars. Home-made tomato sauce from tinned plum tomatoes, garlic, olive oil, and herbs contains naturally occurring sugars only. Making your own is quicker than most people expect.
5. Be sceptical of "healthy" snack products. Cereal bars, fruit bars, protein bars, rice cakes with flavoured coatings, and similar products are frequently high in free sugars despite health-oriented marketing. A handful of unsalted nuts and a piece of whole fruit provides more nutrition, more fibre, and substantially fewer free sugars than most packaged snack products.
6. Watch portion sizes on condiments. Ketchup, brown sauce, and sweet relishes are used in small amounts but daily use adds up. Buying no-added-sugar versions, or using them more sparingly, is an easy reduction without much sacrifice.
7. Use the Food Insight scanner. Scan any product with a UK barcode to see the total sugars figure, the ingredient list (which will reveal sugar synonyms), and the full NOVA processing group. If a product has a long ingredient list with several sugar synonyms, the scanner flags this alongside other nutritional concerns.

For the broader picture of how to shift your daily diet towards minimally processed foods, see the article on whole foods.

The UK sugar tax: what happened

The Soft Drinks Industry Levy, commonly called the sugar tax, was announced in March 2016 and came into effect in April 2018. It applies to soft drinks containing 5g or more of sugar per 100ml (a lower tier at 5g, a higher tier at 8g). Pure fruit juices and milk-based drinks are exempt.

The levy has had measurable effects:

• Sugar content in soft drinks fell by approximately 30% following the levy, largely because manufacturers reformulated products to avoid the charge.
• A Cambridge, Bath, and Oxford study (Journal of Epidemiology and Community Health, 2024) found daily free sugar intake fell by around 5g in children and 11g in adults in the year after the levy came into force.
• The levy has raised over £1.5 billion in revenues since introduction.

The levy is an example of a structural change producing measurable dietary improvements, consistent with the view that individual behaviour change alone is insufficient when the food environment is saturated with high-sugar products. The same modelling that estimated 300,000 diabetes cases prevented assumed a continuation of reformulation pressure rather than consumer choice alone.

Critics have noted that the levy covers soft drinks only, leaving high-sugar breakfast cereals, confectionery, flavoured yogurts, and other significant free sugar sources untouched.

Key statistics at a glance