Free sugars are all the sugars added to foods and drinks by manufacturers, cooks, or consumers, plus the sugars naturally present in honey, syrups, fruit juices, and fruit juice concentrates. The term draws a specific line: sugars inside whole fruit, vegetables, and plain dairy products are not free sugars, but the moment fruit is juiced or pureed, its sugars cross into the free sugar category. The WHO recommends keeping free sugars below 10% of your total daily calories, with an ideal target of less than 5%, which works out to roughly 25 grams or 6 teaspoons a day for an adult.
What Counts as a Free Sugar
The simplest way to think about it: if the sugar was released from its original food structure or added to something during preparation, it’s a free sugar. Table sugar stirred into coffee, honey drizzled on yogurt, maple syrup on pancakes, and high-fructose corn syrup in a soft drink all qualify. So does the sugar in a glass of orange juice, even though no one added anything to it. The act of juicing breaks down the fruit’s cellular structure, releasing the sugars so they behave more like added sweeteners in your body.
Sugars that are not free sugars include those locked inside the cell walls of whole fresh, cooked, or dried fruit and vegetables, and the lactose naturally present in plain milk and unsweetened yogurt. These remain bound within a food matrix of fiber, water, and other nutrients that slows digestion and affects how your body responds to them. Research consistently shows that whole fruit produces a smaller blood sugar spike and greater feelings of fullness than the equivalent amount of fruit juice, which triggers metabolic responses closer to those of a sugary soda.
Why the Distinction Matters
Your liver handles sugars differently depending on how they arrive. When fructose (one of the two main simple sugars) floods the liver quickly, as it does from juice or soda, the liver ramps up production of a specific enzyme involved in the first step of fructose processing. Animal research from the National Institute of Diabetes and Digestive and Kidney Diseases found that both fructose and glucose promote fat buildup in the liver, but through different mechanisms, and fructose was associated with worse metabolic outcomes overall.
In human studies, the pattern holds. The Framingham Heart Study, tracking over 14,000 people across three generations, found that frequent consumers of sugar-sweetened beverages had significantly increased liver fat, higher triglycerides and cholesterol, and lower levels of protective HDL cholesterol. Even a four-week study of increased sugar intake was enough to raise fasting triglycerides, LDL cholesterol, and leptin (a hormone involved in appetite regulation), all of which are precursors to diabetes and cardiovascular disease.
That said, free sugar alone isn’t the whole story. Large-scale analyses have shown that higher sugar intake tends to come alongside higher calorie intake in general, suggesting that excess calories from all sources, not just sugar, drive weight gain. Free sugar is a particularly easy way to overconsume calories because it adds energy without filling you up.
Free Sugars and Tooth Decay
Bacteria on the surface of your teeth convert free sugars into acids that erode tooth enamel over time. This process is dose-dependent: the more free sugar you consume and the more frequently you consume it, the greater the damage. The WHO identifies a clear threshold: rates of tooth decay rise when free sugar intake exceeds 10% of total calories, and dropping below 5% provides additional protection. This relationship holds across all age groups, from young children through older adults, making free sugar reduction one of the most effective strategies for preventing cavities alongside fluoride toothpaste.
How Much Is Too Much
The WHO’s strong recommendation is to keep free sugars below 10% of total energy intake. For an adult eating around 2,000 calories a day, that translates to about 50 grams, or 12 teaspoons. The conditional (ideal) target of 5% cuts that in half to roughly 25 grams, or 6 teaspoons. For context, a single 12-ounce can of cola contains about 39 grams of sugar, which would push you past the ideal limit in one drink.
For children aged 2 to 18, the American Academy of Pediatrics recommends a maximum of 25 grams (6 teaspoons) per day. Children under 2 should avoid free sugars entirely. These numbers are easy to exceed when you consider that flavored yogurts, breakfast cereals, granola bars, and fruit-flavored drinks often contain significant amounts of free sugar even when marketed as healthy options.
Spotting Free Sugars on Labels
Free sugars appear under dozens of names on ingredient lists. Recognizing them takes a bit of practice, but a few patterns help. Any ingredient ending in “-ose” is a sugar: glucose, fructose, sucrose, maltose, dextrose, and lactose all qualify when added to a product. Beyond those, watch for:
- Sugars by other names: cane sugar, confectioner’s sugar, turbinado sugar, coconut sugar, raw sugar
- Syrups: corn syrup, high-fructose corn syrup, rice syrup, golden syrup, agave syrup
- Other sweeteners: honey, molasses, caramel, fruit juice concentrate
A product can list several of these separately so that no single one appears near the top of the ingredients list, even though sugar in total makes up a large portion of the food. Checking the “total sugars” and “added sugars” lines on the nutrition facts panel gives you a clearer picture. In many countries, “added sugars” on the label captures most free sugars, though it may not include fruit juice used as a sweetener, which technically counts as a free sugar under the WHO definition.
Free Sugars vs. Added Sugars
These two terms overlap heavily but aren’t identical. All added sugars are also free sugars. The key difference is that “free sugars” also includes the naturally occurring sugars in fruit juice, fruit juice concentrate, and pureed fruit or vegetables, while “added sugars” as defined for nutrition labeling purposes typically does not. This means a smoothie made from 100% fruit juice with no added sweetener contains zero “added sugars” on the label but can be high in free sugars.
This distinction matters because juice and purees produce metabolic effects that look much more like soda than like whole fruit. If you’re tracking your intake, treating juice as a source of free sugar rather than a serving of fruit gives you a more accurate picture of what’s happening in your body.
Practical Ways to Reduce Free Sugars
Drinks are the single largest source of free sugars for most people. Replacing soda, fruit juice, sweetened coffee drinks, and flavored waters with plain water, unsweetened tea, or sparkling water with a slice of citrus eliminates a substantial portion of daily intake without changing your meals at all. Eating whole fruit instead of drinking juice gives you the same vitamins and flavor with the added benefit of fiber, which slows sugar absorption and helps you feel full.
At the grocery store, comparing brands within the same product category often reveals surprising differences. Two pasta sauces sitting side by side on the shelf can differ by 8 or 10 grams of sugar per serving. The same is true of bread, salad dressings, and flavored oatmeal. Choosing plain versions and adding your own flavor (fresh fruit on oatmeal, oil and vinegar on salad) puts you in control of how much free sugar ends up in your food.