Sugar free and no added sugar are two different claims about two different things, and only one of them tells you how much sugar is in the food. Neither of them tells you anything at all about calories.
In the US, the front of a package is regulated in a narrow way. A short list of phrases has legal definitions and a manufacturer has to meet them. Everything else on the front is design. When we call a recipe no added sugar, that phrase means something specific, and it is worth knowing exactly what, because it is not what most people assume.
The three phrases and what each one is actually promising
Sugar free. Less than 0.5 grams of sugars per serving. Not zero, under half a gram. It is a strict threshold, and it is measured per serving, which matters more than it sounds like it should.
No added sugar. Nothing sweet was added during processing. It says nothing about what was already in there. A bar built on dates and raisins can carry this claim honestly while being mostly sugar by weight, and the total sugars line on the panel will show it, because fruit sugar is still sugar as far as the label is concerned.
Reduced sugar, or less sugar. At least 25 percent less than a comparable reference product. Twenty-five percent less than something extremely sweet leaves you with something sweet.
There is one more rule, and almost nobody reads the sentence it produces. A sugar-free product that is not also low calorie or reduced calorie has to say so somewhere on the package. That sentence exists because the two ideas get conflated constantly, and it is usually printed in the smallest type on the box.
The rounding gap
Anything under 0.5 grams per serving prints as 0. So a cookie with 0.4 grams of sugar is a zero-sugar cookie on the panel, which is fair enough for one cookie. Eat three and you have had 1.2 grams reported to you as nothing at all.
That gap is small for a cookie and much bigger for a product you eat several servings of without thinking, like a drink mix or a syrup. The panel is honest per serving. It just does not do the multiplication for you.
Which is why the first two lines are the ones to read first. Serving size, then servings per container. Every number below is scaled to the first and multiplied by the second.
Sugar alcohols are not one ingredient
Erythritol, xylitol, maltitol, sorbitol and isomalt get grouped under one heading, and they behave very differently once you have eaten them.
Erythritol is mostly absorbed in the small intestine and leaves the body in urine, so relatively little of it reaches the colon. That is the reason it tends to be the gentlest of the group for most people. Maltitol and sorbitol are a different story. A large share of them reaches the colon and gets fermented by bacteria there, and that fermentation is the entire origin of the reputation sugar alcohols have.
So 15 grams of maltitol and 15 grams of erythritol are not comparable, even though the panel may present them identically.
The breakout line for sugar alcohols is not required in every case, so a product can contain them without itemizing the grams. The ingredient list is more reliable. Most of them end in -itol, and isomalt is the one that does not.
Tolerance varies person to person. If a particular one is new to you, a small amount first is a reasonable way to find out where you sit.
Net carbs is not a real number
Net carbs is not defined by the FDA, is not regulated, and does not appear on a nutrition panel. It is arithmetic a brand does on its own and prints on the front.
The usual formula subtracts fiber and sugar alcohols from total carbohydrate, on the reasoning that neither is absorbed the way starch and sugar are. That reasoning holds up better for some ingredients than others, which is the whole problem. Two products can both claim 2 grams of net carbs while one is sweetened with erythritol and the other with maltitol, and the subtraction is doing much more work in the second case.
Total carbohydrate is the defined, regulated line. If a carbohydrate number matters to you for a medical reason, use that one and treat the front-of-package figure as a marketing estimate. And the targets your care team gives you beat any rule of thumb from a recipe site, this one included. Nothing here is medical advice.
Why a genuinely sweet dessert can print zero sugar
Allulose is worth understanding on its own, because it explains a label that otherwise looks impossible.
It is a rare sugar rather than a sugar alcohol, and FDA guidance allows manufacturers to leave it out of the total sugars and added sugars lines while still counting it in total carbohydrate. So a product sweetened with allulose can show grams of carbohydrate and zero grams of sugar on the same panel, legitimately, and still taste properly sweet.
Our sugar-free marshmallows are built on an allulose syrup, and the nutrition line says 4g of carbs and 15 calories per marshmallow, with a note that the carbs are mostly allulose, because the raw number on its own would not tell you much.
One catch for the ingredient-list method: allulose ends in -ose, the same as glucose, fructose and dextrose, which are all straightforward sugars. The suffix flags it for a second look. It does not settle anything.
The fat that replaced the sugar
Sugar does structural work in a dessert beyond making it sweet. Take it out and something has to fill the space, and that something is usually fat. A sugar-free cookie can carry more calories than the ordinary version of the same cookie.
We publish fat for this reason. Our dark chocolate almond bark is 130 calories a piece, 10 grams of fat and 5 grams of sugar, because it is dark chocolate and toasted almonds. Printing the sugar and leaving off the fat is the oldest move in this category, and it works because the front of the package has already told you what to look at.
The order to read in
Serving size and servings per container, first, before anything else.
Then total carbohydrate, then total sugars, then added sugars. Added sugars carries a percent daily value on US labels, calculated against a daily value of 50 grams, which is a useful anchor when a number is hard to picture.
Then the ingredient list, which is ordered by weight, heaviest first. Read the first three. Then scan the rest for anything ending in -itol or -ose.
A label is not trying to deceive you so much as it is built to be read in one order, front to back, largest type to smallest. Reading it backwards takes about twenty seconds and gets a different answer more often than you would expect. Our 27 sugar-free desserts under 100 calories all print their numbers in that order for the same reason.
