“Sugar free” on a food label means the product contains less than 0.5 grams of sugar per serving. It does not mean zero sugar, zero calories, or zero carbohydrates. The term is regulated by the FDA in the U.S. and has a similar definition in Europe, but it leaves room for ingredients that can still affect your blood sugar, your digestion, and your waistline.
The FDA’s Official Definition
To carry a “sugar free” label in the United States, a food must contain less than 0.5 grams of sugars per serving. That threshold applies both to the labeled serving size and to the “reference amount customarily consumed,” a standardized portion set by the FDA. So a product can technically contain a small amount of sugar and still legally say “sugar free” on the package.
There’s a second rule most people don’t know about. If a sugar-free product isn’t also low in calories, it must include a disclaimer like “not a low calorie food” or “not for weight control” right next to the sugar-free claim, every time it appears on the label. This exists because the FDA recognizes that consumers see “sugar free” and assume “diet friendly,” which isn’t always the case.
The European Union uses a nearly identical standard: no more than 0.5 grams of sugars per 100 grams or 100 milliliters. The key difference is that the EU measures against a fixed weight rather than a serving size, which can make the EU standard slightly stricter for products with small serving sizes.
Sugar Free vs. No Added Sugar vs. Unsweetened
These three terms mean different things, and mixing them up is one of the most common mistakes people make when reading labels.
- Sugar free: Less than 0.5 grams of sugar per serving. The product may use artificial sweeteners or sugar alcohols to replace the taste of sugar.
- No added sugar: No sugar or sugar-containing ingredients (like fruit juice concentrate or jam) were added during processing. The food can still contain naturally occurring sugars. A bottle of “no added sugar” apple juice, for example, still has plenty of sugar from the apples themselves.
- Unsweetened: No sweetener of any kind was added, including artificial sweeteners. This is the most straightforward claim, but the product can still contain natural sugars.
A “no added sugar” product could have 20 or 30 grams of naturally occurring sugar per serving and still carry that claim legally. A “sugar free” product cannot.
What Replaces the Sugar
Sugar-free products still need to taste sweet, so manufacturers use two main categories of substitutes: sugar alcohols and high-intensity sweeteners.
Sugar alcohols (also called polyols) include erythritol, xylitol, sorbitol, and maltitol. Despite the name, they contain no alcohol. They occur naturally in some fruits and are partially absorbed by your body, so they do contribute some calories, typically 0.2 to 3 calories per gram compared to 4 calories per gram for regular sugar. Their effect on blood sugar varies widely. Erythritol has a glycemic index of 0, meaning it causes essentially no blood sugar spike. Xylitol sits at 12, sorbitol at 4. But maltitol has a glycemic index of 35, which is lower than table sugar’s 65 but far from negligible. If you’re managing diabetes or watching blood sugar closely, the specific sugar alcohol matters.
High-intensity sweeteners include sucralose (Splenda), aspartame (Equal), and saccharin (Sweet’N Low). These are hundreds of times sweeter than sugar, so only tiny amounts are needed. They contribute virtually no calories and don’t raise blood sugar.
Sugar Free Doesn’t Mean Calorie Free
This is the biggest misconception. A sugar-free cookie can still be packed with calories from fat, flour, and sugar alcohols. Some sugar-free products are nearly identical in total calories to their regular counterparts because the sugar was replaced with other calorie-containing ingredients.
In 2023, the World Health Organization recommended against using non-sugar sweeteners as a strategy for weight control. Their review of the evidence found that replacing sugar with these sweeteners didn’t lead to meaningful long-term reductions in body fat. The reasoning is partly behavioral: people who eat sugar-free foods sometimes compensate by eating more of other things, or they overeat the sugar-free product itself because they perceive it as healthier.
Watch for Hidden Blood Sugar Spikes
Some sugar-free products contain maltodextrin, a carbohydrate derived from starch that technically isn’t a “sugar” under FDA definitions. Maltodextrin is digested and absorbed at roughly the same rate as pure glucose, producing a comparable insulin response. It’s commonly used as a filler or texture agent in sugar-free powdered drinks, protein bars, and candy. If you see maltodextrin on the ingredient list of a sugar-free product, that product can still raise your blood sugar significantly, despite what the front label suggests.
Digestive Side Effects of Sugar Alcohols
Sugar alcohols are poorly absorbed in the gut, which is why they contribute fewer calories. The downside is that the unabsorbed portion reaches your large intestine, where bacteria ferment it, producing gas, bloating, and in larger amounts, diarrhea. The threshold varies by person and by type of sugar alcohol.
Sorbitol is the most likely to cause problems. Research shows the laxative threshold for sorbitol is about 0.17 grams per kilogram of body weight for men and 0.24 grams for women. For a 150-pound man, that’s roughly 12 grams, an amount easily reached by eating a handful of sugar-free candies. Erythritol is better tolerated because about 90% of it is absorbed in the small intestine before reaching the colon. Its laxative threshold is about four times higher than sorbitol’s. If you’re new to sugar-free products and notice digestive issues, checking which sugar alcohol the product uses can help you identify the culprit.
Benefits for Dental Health
One area where sugar-free products offer a genuine advantage is oral health. Xylitol in particular actively fights tooth decay rather than just avoiding it. The bacteria responsible for cavities absorb xylitol but can’t use it for energy. This creates a cycle that starves and kills the bacteria, reducing plaque buildup, lowering acid production in your mouth, and stimulating saliva flow. Sugar-free gums sweetened with xylitol have the strongest evidence behind them, and dentists routinely recommend them for this reason.
Other sugar alcohols like erythritol and sorbitol are also non-fermentable by oral bacteria, meaning they won’t feed cavity-causing microbes the way sugar does. But xylitol is the only one that actively reduces bacterial populations rather than simply not contributing to the problem.
How to Read the Label
The “sugar free” claim on the front of the package tells you very little on its own. Flip the product over and look at three things: total calories, total carbohydrates (which includes sugar alcohols and maltodextrin), and the ingredient list. Sugar alcohols are sometimes listed separately under total carbohydrates, which helps you gauge both the blood sugar impact and the digestive risk. If the product is high in calories despite being sugar free, or if maltodextrin appears near the top of the ingredient list, the product may not deliver the health benefit you’re looking for.