Is allulose a sugar?

Both answers are true, which is why the question keeps getting asked.

The chemistry

Allulose is a monosaccharide, a single sugar unit, in the same family as glucose and fructose. It occurs in small amounts in figs and raisins. It is sweet, it browns when heated, and it behaves in a recipe roughly the way sugar does.

If your definition of sugar is chemical, it is a sugar and there is no argument.

The label

The body absorbs allulose and then largely fails to metabolise it, excreting most of it unchanged. It supplies roughly a tenth of the energy of table sugar and it does not meaningfully raise blood glucose.

In October 2020 FDA announced its “intent to exercise enforcement discretion for the exclusion of allulose from the amount of Total Sugars and Added Sugars declared on the Nutrition Facts and Supplement Facts label and use of a general factor of 0.4 calories per gram (kcal/g) for allulose”.

Two details matter about that sentence.

Enforcement discretion is not a rule change. The regulation was not rewritten. FDA said it would not act on this divergence pending a rulemaking, which is a different and more provisional thing than a definition being changed.

The exclusion stops at the sugar lines. Allulose is still counted in total carbohydrate. So a panel reading carbohydrate present, sugars zero, is exactly what the guidance produces.

What that means when you are reading a panel

If you are avoiding sugar because of blood glucose, the label is telling you something useful and the zero is doing its job.

If you are avoiding sugar for another reason, or if you are counting carbohydrate rather than sugar, the zero on the sugars line is not the number you want and total carbohydrate is. The wider version of this problem is on the page for reading labels when you are watching blood sugar.

And if you want to know how much allulose is in the product, the answer is that you generally cannot, because the same exclusion that lets the panel print zero removes the figure you would need.

It is not the same as erythritol

Erythritol is the ingredient allulose is most often confused with, and they are genuinely different.

Erythritol is a sugar alcohol, and sugar alcohols are declared under their own voluntary line rather than excluded from the sugars line. Allulose is a true sugar that is subtracted from the sugars line by decision. The two arrive at a similar-looking panel by entirely different routes, and only one of them currently carries an open safety question.