The short answer
- Sugar-free is an FDA-regulated claim: the food must contain less than 0.5g of sugars per reference amount and per labeled serving.
- 0g added sugar only means no sugars were added during processing. Naturally occurring sugars can still be present in any amount.
- “No added sugar” is a separate claim with its own ingredient conditions — and it is not the same as sugar-free either.
What “sugar-free” legally means
Under FDA nutrient-content claim rules, “sugar free” may be used when a food contains less than 0.5g of sugars per reference amount customarily consumed and per labeled serving. Two further conditions matter in practice:
- The claim refers to all sugars — naturally occurring and added together — not just added sugars.
- If the food is not low calorie or reduced calorie, the label must flag that next to the claim (for example, “not a reduced-calorie food”), so shoppers do not confuse sugar-free with calorie-free.
Because the threshold is 0.5g rather than absolute zero, a sugar-free product can legally contain a trace of sugar. Conversely, a product with 0g added sugar can contain far more total sugar than any sugar-free product ever could.
What “no added sugar” requires
“No added sugar” (or “without added sugar”) has its own conditions. Broadly, the food and its ingredients must contain no added sugars — no sugar or sugar-containing ingredient (such as jam or concentrated juice used as a sweetener) may be added during processing or packaging. In addition, the food that the product resembles and substitutes for must normally contain added sugars; you cannot claim “no added sugar” on a food that never has sugar added anyway, such as plain rice, because that would imply a distinction that does not exist.
Two cautions follow. First, “no added sugar” says nothing about the total sugar content — 100% fruit juice qualifies and still contains roughly 24g of sugar per cup. Second, unless the product is low or reduced calorie, the claim must be accompanied by a statement directing shoppers to the Nutrition Facts panel for information on sugars and calorie content.
Worked example: milk, juice, and a sweetened yogurt
Three products, one cup (about 240g) servings:
- Plain milk: Total Sugars about 12g, Includes 0g Added Sugars. Not sugar-free — the 12 grams are lactose, present in milk itself.
- 100% apple juice: Total Sugars about 24g, Includes 0g Added Sugars. Eligible for a “no added sugar” claim, but far from sugar-free.
- Sweetened flavored yogurt: Total Sugars about 21g, Includes 9g Added Sugars. Fails both claims.
Only a product with less than 0.5g of total sugars per serving — think diet soda sweetened with non-sugar sweeteners — can carry the sugar-free claim. Reading “0g added” as “sugar-free” would misclassify both the milk and the juice.
A quick glossary of the phrases
- Sugar-free: regulated claim; less than 0.5g total sugars per serving.
- No added sugar / without added sugar: regulated claim; no sugar or sugar-containing ingredient added, with the substitution conditions above.
- 0g Added Sugars (Nutrition Facts line): a measured value on the panel, subject to rounding rules; it is data, not a front-of-pack claim.
- Unsweetened: not a formally standardized FDA claim; read the panel and ingredient list to see what it means for that brand.
Why the rounding detail matters
Nutrition Facts values are rounded. An added-sugars value below 0.5g per serving can be declared as 0g, so “0g added” is not a guarantee of literally zero grams — it is a declaration within the rounding rules. For most comparisons this is immaterial, but it explains why two databases can disagree by a fraction of a gram, and why the claim “sugar-free” (also built on the 0.5g threshold) and the panel line are related but not interchangeable statements.
Where “reduced sugar” fits in
One more claim often appears in the same aisle: “reduced sugar” or “less sugar.” This is a relative claim, not an absolute one — the food must contain at least 25% less sugars per reference amount than an appropriate reference food (usually the brand's regular version or a representative product in the category), and the label must say what it is being compared against. A reduced-sugar ketchup can still contain several grams of sugar per tablespoon; the claim only certifies the improvement over the reference. Read it as “less than the usual version of this,” then check the Total Sugars line for the absolute number.
A 30-second verification routine
- Ignore the front of the package until step four.
- Read Total Sugars and the “Includes Added Sugars” line for your real portion.
- Scan the ingredient list for sweeteners (sugar, syrups, honey, juice concentrate) to see where sweetness comes from.
- Now interpret the front-of-pack claim against the panel: sugar-free requires under 0.5g total; no-added-sugar requires no sugar-containing ingredients; 0g added is just the panel value with rounding.
- If two products make different claims, compare them on one basis — total sugar grams at equal portions is usually the cleanest.
How to use this when comparing products
- Decide which question you are asking: total sugar intake, or sugar added during processing.
- For total sugar, read Total Sugars — front-of-pack claims about added sugar will not answer it.
- For processing, read the “Includes Added Sugars” line and the ingredient list.
- Treat front-of-pack phrases as entry points, then verify on the panel; only “sugar-free” certifies anything about total sugar, and even that is a threshold, not zero.
A note on non-sugar sweeteners
Sugar-free products are usually sweetened with something else — aspartame, sucralose, stevia, monk fruit, or sugar alcohols such as erythritol and xylitol. These do not count as sugars on the panel, so the claim can be accurate while the product still tastes sweet. Sugar alcohols, when present, appear on their own line under Total Carbohydrate. Whether that trade-off suits you is a separate question from the sugar numbers, and the ingredient list is where to check it.
The bottom line
0g added sugar, “no added sugar,” and “sugar-free” are three different statements. Only sugar-free is about total sugar, and it means under 0.5g per serving. For the claim definitions, see the FDA nutrient-content claim requirements and the FDA added-sugars guidance. When two packages make different front-of-pack promises, AptBite puts both products' total and added sugar lines side by side so the claim and the data stay separate. This article is general label education, not medical or dietary advice.
