Allulose is a rare sugar that tastes sweet but contributes far less metabolizable energy than sucrose. Chemically it is a monosaccharide and a C-3 epimer of fructose, also known as D-psicose.
Small amounts occur naturally in selected foods, while commercial allulose is generally produced through enzymatic conversion of other sugars.
It is absorbed but barely metabolized
A large share of ingested allulose is absorbed from the small intestine and later excreted rather than oxidized like glucose or fructose.
This is why its energy contribution is much lower than the 4 calories per gram conventionally assigned to traditional sugars.
FDA allows manufacturers to use 0.4 calories per gram for U.S. Nutrition Facts calculations.
Allulose is less sweet than table sugar
It is commonly described as roughly 70% as sweet as sucrose, although perceived sweetness varies with concentration and the food matrix.
Because it is a real sugar molecule rather than a high-intensity sweetener, it also contributes bulk and mass.
This makes it technologically different from stevia, sucralose, or monk fruit extracts, which are used in tiny quantities.
It behaves more like sugar in cooking
Allulose can participate in browning chemistry and contribute color and flavor during baking.
It can brown more readily than sucrose under some conditions, which means a recipe converted one-for-one may darken faster.
It also influences moisture retention and texture in ways an intense sweetener alone cannot.
Its glycemic effect is very small
Because the body metabolizes very little allulose, it does not deliver the same available glucose load as sucrose or glucose.
Acute trials have reported lower post-meal glucose responses when allulose replaces or accompanies conventional carbohydrate, although the size of the effect depends on dose and meal composition.
A product sweetened with allulose can still contain starch or other sugars, so the whole Nutrition Facts panel matters.
U.S. labels treat allulose differently
FDA requires allulose to remain within Total Carbohydrate but allows it to be excluded from Total Sugars and Added Sugars because it is metabolized differently from traditional sugars.
Manufacturers may also calculate energy at 0.4 kcal/g rather than 4 kcal/g.
This labeling approach is specific to U.S. regulation and should not be assumed internationally.
Regulatory status differs across markets
Countries and regions use different approval systems for novel ingredients.
In the European Union, novel foods require authorization before marketing. EFSA evaluated one D-allulose application in 2025 and concluded that safety could not be established from the submitted dossier because important data gaps remained.
That conclusion reflects the evidence available for that application rather than proving that allulose is inherently toxic.
Large amounts can cause GI symptoms
Unabsorbed allulose reaches the large intestine, where osmotic effects and fermentation can contribute to symptoms.
Higher single doses can cause bloating, rumbling, abdominal discomfort, or diarrhea in some people.
Tolerance depends on both the amount eaten at once and total daily intake.
Allulose is not erythritol or stevia
Erythritol is a sugar alcohol, while stevia and monk fruit are high-intensity sweeteners. Allulose is a monosaccharide that provides bulk, browning, and water-binding properties more similar to sugar.
Allulose also behaves differently in frozen and baked foods. Because it depresses freezing point and binds water, it can help keep frozen desserts softer, while its rapid browning can make cookies or cakes darken sooner than expected.
That means a one-for-one sugar replacement is not always a one-for-one recipe replacement. Texture, moisture, sweetness, and browning may all need adjustment.
Commercial blends sometimes combine allulose with stevia or monk fruit because allulose alone is less sweet than sucrose. The intense sweetener supplies extra sweetness while allulose supplies bulk and sugar-like functionality.
Serving size still matters when judging tolerance.
Dose matters.
The practical rule: allulose provides sugar-like functionality with very little metabolizable energy, but GI tolerance and local regulatory status matter as much as its low-calorie label.
Frequently asked questions
How many calories does allulose have?
FDA allows 0.4 calories per gram on U.S. labels, compared with 4 calories per gram for traditional sugars.
Does allulose raise blood sugar?
It has a very small direct glycemic effect because very little is metabolized, although foods containing it may include other carbohydrates.
Is allulose the same as erythritol?
No. Allulose is a monosaccharide; erythritol is a sugar alcohol with different chemistry and functional properties.
Sources
- FDA — Sugars That Are Metabolized Differently Than Traditional Sugars — Explains U.S. allulose labeling and the 0.4 kcal/g caloric value.
- EFSA — Safety of D-allulose as a novel food — 2025 evaluation in which safety could not be established for one dossier because of missing data.
- European Commission — Novel Food authorisations — Explains the EU novel-food authorization process.