Sugar alcohols are distinct from artificial sweeteners such as Equal (NutraSweet) or Sweet 'N Low because they supply as much, if not more, caloric energy than regular sugar. Artificial sweeteners provide virtually no caloric energy.
Why in the past have sugar alcohols been recommended for people with diabetes? The body either absorbs these sugars more slowly or metabolizes them to glucose more slowly. Thus, they do not cause as sharp a rise in blood sugar as regular table sugar (sucrose). However, the side effects of foods containing sugar alcohols (they may cause bloating and diarrhea when more than 30g/day, the amount in 10 to 15 hard candies, are consumed), along with their additional calories, make them not as good a choice for managing diabetes as their sucrose counterparts.
One documented benefit: Sugar alcohols are not readily used by ordinary mouth bacteria ... thus they have a use in preventing dental caries. You'll see them used often in chewing gums and candy.
There are four sugar alcohols currently available in the US: mannitol, sorbitol, xylitol, and maltitol. You can recognize the presence of a sugar alcohol in a food by glancing at its label. Most end with the suffix -ol.
Mannitol
Mannitol has only 70% of the relative sweetness of sugar. Because it is less sweet than sucrose, more needs to be used. Since all the sugar alcohols contain virtually the same amount of calories as regular sugar (4 kcalories per gram), using them as a sugar substitute will cause the host food to be more calorically dense than if regular sugar were used.
Mannitol lingers unabsorbed in the intestine for a long time, supplying energy to intestinal bacteria. As bacteria consume mannitol, they multiply, they attract water, and they produce irritating waste ... causing bloating and diarrhea.
Sorbitol
Sorbitol has only 50% of the relative sweetness of sugar. Because it is only half as sweet as sugar, twice the amount (with twice as many calories) has to be used to deliver a similar amount of sweetness. But, because its tendency to cause diarrhea is less than mannitol's, of the two, it is preferred.
You'll see sorbitol as an ingredient in sugar-free gums and candies.
Xylitol
Xylitol has the same relative sweetness as sugar. It also has a reputation for preventing dental caries. The FDA has approved it for special dietary uses. You will see it as a popular ingredient in chewing gums.
Maltitol
Maltitol has 75% of the relative sweetness of sugar. You won't see it widely used since its manufacture from maltose is expensive.
Some carbonated beverages and canned fruit may still use it as a cavity-preventing sweetener.
If you're looking for a sugar substitute, consider an artificial sweetener instead of a sugar alcohol. Sweeteners such as aspartame (Equal), saccharine (Sweet 'N Low), and acesulfame K (Sweet One, Sunette) contribute virtually no carbohydrates or calories to foods. Thus they are beneficial in the management of diabetes.