A sugar alcohol (also known as a polyol, polyhydric alcohol, or polyalcohol) is a hydrogenated form of carbohydrate, whose carbonyl group (aldehyde or ketone, reducing sugar) has been reduced to a primary or secondary hydroxyl group. They are commonly used for replacing sucrose in foodstuffs, often in combination with high intensity artificial sweeteners to counter the low sweetness. Some common sugar alcohols are:

• mannitol
• sorbitol
• xylitol
• maltitol
• lactitol

(Maltitol and lactitol are not completely hydrogentated compounds - they are a monosaccharide combined with a polyhydric alcohol)

In the human body, sugar alcohols are metabolized differently from sugars. They are usually incompletely absorbed in the intestines, via insulin-independent mechanisms. Because of their lessened caloric value and impact on the blood sugar, they are often used by diabetics and followers of low-carbohydrate diets such as the Atkins' Diet. Abdominal discomfort, bloating , and a laxative effect are commonly reported side effects of excess sugar alcohol consumption.

Calorific content

The calorific content of the poly-ols has been measured in studies. Values differ for each of them but in the EU, there is a defined content of 2.4 J/g for all.

Polyhydric alcohols not normally referred to as "sugar alcohols" include:

• ethylene glycol
• glycerol