Is "Sugar Free" a Scam? What the Label Legally Allows

Written by David Roberts, MPH, Co-founder, Mara Labs

It's not that labels are lying to you. They are simply stating a more specific fact than what most people are wondering.

You want to know whether the food will affect your blood sugar, your waistline, and your health. The label is answering a legal definition written in 1993.

What does "sugar free" legally mean?

"Sugar-free" legally means the food contains less than 0.5 grams of sugars per labeled serving. [1]

That is the entire test. If the sugar present is under half a gram, and the claim is permitted.

This makes two things true:

1) A serving can be made small enough to land under the threshold, which is a documented but sneaky practice.

2) And a food can claim to be sugar-free while containing ingredients that behave in the body a great deal like sugar.

The FDA has acknowledged that consumers associate an absence-of-sugar claim with weight control and reduced calories.

That is why a sugar-free food that is not also low-calorie or reduced-calorie has to carry a disclaimer pointing you to the nutrition panel. [1]

Why don't sugar alcohols count as sugar?

The decision not to count sugar alcohols as "sugar" came simply as a decision by the FDA. That is a regulatory definition, not a biological one.

When the agency wrote the rules on nutrient content claims, it considered whether to define sugar alcohols as sugars and chose not to. [2]

So xylitol, erythritol, maltitol, sorbitol, and their relatives can appear in a product labeled sugar-free.

They are declared separately on the nutrition panel, under sugar alcohols, and they do not count toward the sugars line.

They are not calorie-free. Most sugar alcohols carry somewhere between 0.2 and 2.6 calories per gram, against 4 for sugar, so the sugar is reduced, but definitely not absent.

They also count as carbohydrates. For anyone tracking carbohydrates rather than sugar, sugar-free and low-carb are different claims answering different questions.

What do sugar alcohols do in the body?

They are absorbed incompletely, which is the source of both their appeal and their most common problem.

What is not absorbed in the small intestine travels to the colon, where bacteria ferment it. That produces gas, and it draws water into the bowel.

The result is the bloating, cramping, and laxative effect that sugar-free candy is known for.

Blood sugar response varies more than people assume. Erythritol is close to inert.

Maltitol produces a considerably larger glucose response, which is important information for anyone choosing these products specifically to avoid that.

Is xylitol bad for your heart?

There is evidence in the research to this effect, but there is also an argument about what it means.

In 2024, a Cleveland Clinic team published a study in the European Heart Journal examining fasting blood levels of xylitol.

It ran a discovery cohort of 1,157 patients and a validation cohort of 2,149. People in the highest third for circulating xylitol had a higher rate of heart attack, stroke, and death over three years, with an adjusted hazard ratio of 1.57. [3]

The team went further than the association. Xylitol increased platelet reactivity in human blood samples and raised clot formation in a mouse model.

In ten volunteers given a xylitol-sweetened drink, measures of platelet responsiveness rose in every subject. [3]

Now the argument. The blood levels in the cohort study were fasting levels, and the human body produces xylitol on its own.

So higher fasting xylitol may reflect a person's metabolic state rather than what they have been eating. That would make it a marker of risk rather than a cause.

That objection was published in the same journal by two separate research groups, and the original authors responded in print. [4] [5]

The study's own authors call for long-term safety studies, which is the correct position when the mechanism is suggestive and the human evidence is observational.

What that adds up to is not a reason to panic. It is a reason to notice that a sweetener marketed partly to people with cardiovascular and metabolic risk has an open question attached to it.

Why is xylitol so dangerous for dogs?

A dog's pancreas responds to xylitol as though it were sugar, and a person's does not.

In dogs, xylitol triggers a rapid and powerful insulin release, which causes blood sugar to crash.

Doses above roughly 100 mg per kilogram of body weight have been associated with hypoglycemia. Doses above 500 mg per kilogram can cause severe liver injury or failure. [6]

Those are small numbers. A single piece of sugar-free gum can carry enough xylitol to put a small dog into hypoglycemia.

Signs can appear within 30 minutes, or be delayed 12 to 18 hours if the xylitol is in something that slows absorption, such as gum. Liver damage may not become apparent for 24 to 48 hours. [6]

Check labels for birch sugar and wood sugar, which are the same compound under different names.

The common exposures are sugar-free gum, mints, candy, some specialty peanut butters, chewable vitamins, and human toothpaste.

If a dog eats something containing xylitol, this necessitates an emergency call to a veterinarian or a pet poison line, made before symptoms appear rather than after. Do not induce vomiting unless a veterinarian tells you to.

So is "sugar free" a scam?

Sugar free is not a scam, but it exposes a gap between what the label is required to say and what a shopper assumes it means.

The claim is legally accurate and narrow. It tells you about one line on the nutrition panel.

It tells you nothing about calories, carbohydrate, glycemic response, digestive tolerance, or what else went in to replace the sugar.

The fix is unglamorous: read the ingredient list and the sugar alcohols line rather than the front of the box, and if there is a dog in the house, read it twice.

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