Polyols and Calories - Why the Number on the Label Isn't the Whole Story

If you've ever looked at the nutrition label on a sugar-free product and wondered why the calorie count still seems relatively high despite containing no sugar - the answer lies in how polyols (sugar alcohols) are digested. Understanding this can help you make better sense of the labels on products sweetened with isomalt, xylitol, erythritol or maltitol.

Polyols - also known as sugar alcohols - are a family of low-calorie sweeteners that occur naturally in some fruits and vegetables, and are also produced commercially for use in sugar-free foods. The most commonly used polyols in sugar-free confectionery are:

✔ Isomalt - used in our hard candy and lollipop range - GI of 9, zero nett carbs

✔ Xylitol - GI of 7, tooth-friendly, commonly used in baking and confectionery

✔ Erythritol - GI of 0, virtually zero calories, popular in keto products

✔ Maltitol - used in our no added sugar chocolate range - GI of approximately 35 in powdered form

Regular sugar (sucrose) is fully absorbed in the small intestine and provides approximately 4 calories per gram - all of which become available to the body as energy.

Polyols work differently. When you consume a polyol, a significant portion of it - anywhere from 10% to 99% depending on the specific polyol - is not absorbed in the small intestine at all. Instead it passes through to the large intestine where it is fermented by gut bacteria.

This is important because carbohydrates that are fermented in the large intestine rather than absorbed in the small intestine yield only about 50% of the energy that would otherwise be available. In simple terms - the body gets significantly fewer usable calories from a polyol than the label's total calorie count might suggest.

The actual energy (calorie) value of any polyol depends on three factors working together:

✔ Small intestine absorption rate - what percentage of the polyol is absorbed in the small intestine vs passing through to the large intestine. This varies significantly between different polyols - erythritol, for example, is almost entirely absorbed in the small intestine but then excreted via urine rather than metabolised, giving it virtually zero calories.

✔ Metabolic availability - of the portion that is absorbed in the small intestine, how much of it can the body actually use as energy? Some polyols are absorbed but not fully metabolised, further reducing their effective calorie contribution.

✔ Large intestine fermentation - the portion that reaches the large intestine is fermented by gut bacteria and yields only around 50% of the energy that small intestine absorption would provide. This fermentation process is also responsible for the digestive side effects that can occur when polyols are consumed in large amounts.

The calories and carbohydrates listed on a food label for polyol-containing products are calculated using standard regulatory figures - but these figures do not always reflect the actual energy your body will absorb and use. In practice, the real caloric and glycemic impact of polyols is lower than what appears on the label.

This is why nett carbs - calculated by subtracting fibre and sugar alcohols from total carbohydrates - gives a more accurate picture of a product's true impact on blood sugar and energy intake. For more on this, read our guide: Total Carbs vs Nett Carbs vs Glycemic Carbs - What's the Difference?

✔ Regular sugar (sucrose): 4 calories per gram - fully absorbed

✔ Maltitol (powdered): approximately 2.4 calories per gram

✔ Xylitol: approximately 2.4 calories per gram

✔ Isomalt: approximately 2 calories per gram

✔ Erythritol: approximately 0.2 calories per gram - almost zero

And as explained above - even these figures overstate the actual energy the body derives from most polyols, because a significant portion is fermented rather than absorbed.

Because polyols are fermented in the large intestine rather than absorbed, consuming them in large quantities can cause digestive discomfort - including bloating, gas and loose stools. This is a well-known characteristic of all sugar alcohols and is why most sugar-free products carry an advisory note about excessive consumption.

The good news is that most people tolerate polyols well at normal serving sizes. As a general guideline:

✔ Start with small amounts if you are new to polyol-sweetened products

✔ Limit maltitol-sweetened chocolate to around 25-30g per sitting

✔ Individual tolerance varies - pay attention to how your body responds

✔ Erythritol is the best-tolerated polyol for most people as it is absorbed before reaching the large intestine

Please note: Always consult your doctor or dietitian if you have a medical condition that requires you to carefully manage your calorie or carbohydrate intake.

At Caring Candies all our own-branded products are sweetened with natural polyols - isomalt in our hard candy and lollipop range, and powdered maltitol in our no added sugar chocolate range. No artificial sweeteners, no artificial colourants and no seed oils. Kosher and Halaal certified, made in Cape Town and delivered nationwide.

Shop: caringcandies.com/collections/sugarfree