They are generally less sweet than sucrose (table sugar), so they are often mixed with very sweet artificialsweeteners like aspartame, sucralose and acesulfame potassium, to form a palatable substitute in low sugar, low carbohydrate, and diabetic or "diet" products.
Finally, there is some evidence suggesting artificialsweeteners, which are often used in conjunction with sugar alcohols, may actually contribute to obesity by promoting energy intake.