Sugar Alcohols and Low-Carbohydrate Diets

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Many people wonder about sugar alcohols and low carbohydrate diets. One of the things that low-carbohydrate dieters often miss are sweet flavors. To some, sugar alcohols seem to provide the perfect solution, but do they help or hinder low-carbohydrate diets?


Carbohydrates are a class of macronutrients in foods that contain sugars. Simple carbohydrates contain one or two sugars, and include candy, table sugar, syrup, dairy products, and fruit. Complex carbohydrates contain more than two sugars. Whole grains, vegetables, legumes and seeds are all complex carbohydrates. All carbohydrates affect blood sugar to some extent. When you eat carbohydrates, your blood glucose rises and your body releases insulin to return blood sugar levels to normal. Simple carbohydrates typically raise blood sugar rapidly, while complex carbohydrates cause a slower, more sustained release of blood sugar.

Low-Carbohydrate Diets

There are many low-carbohydrate diets that are proven as effective weight loss methods for dieters. Traditional diets restrict fat and calories in order to bring about weight loss. Low carbohydrate diets, on the other hand, bring about weight loss through varying degrees of carbohydrate restriction, depending on the plan you choose. The basic premise behind all low-carbohydrate diets is the same, however. In the article, "What if It's All Been a Big, Fat Lie," Gary Taubes explains that low-carbohydrate diets work because eating low levels of carbohydrates leads to insulin control, and when there isn't insulin present in your bloodstream, your body burns stored fat as its primary source of fuel.

Different low-carbohydrate diets have differing guidelines about sugar alcohols. Some popular low-carbohydrate diets include:

Sugar Alcohols

Sugar alcohols are neither sugar, nor alcohol. Instead, they are carbohydrates called polyols, whose chemical structure partially resembles sugar and partially resembles alcohol. Sugar alcohols are naturally occurring in plants, and they have varying degrees of sweetness. There are many different types of sugar alcohol, and they have fewer calories than regular sugar, varying from about one calorie per gram to about three calories per gram. Sugar has four calories per gram. The following are all sugar alcohols:

  • Erythritol
  • Xylitol
  • Mannitol
  • Isomalt
  • Sorbitol
  • Lactitol
  • Maltitol

Sugar Alcohol and Glycemic Index

Food scientists measure the effect that a carbohydrate has on blood sugar using the glycemic index. The higher the glycemic index of a carbohydrate food, the more it causes your blood sugar to rise. In general, simple carbohydrates like sugar, and starches such as white flour, have a high glycemic index and lead to a sharp spike in blood sugar. Low-sugar vegetables have a very low glycemic index and have a negligible effect on blood sugar. Sugar alcohols have a glycemic index that ranges from low to moderate. Maltitol has the highest glycemic index, while erythritol has the lowest. Different sugar alcohols affect blood sugar differently, which is why many people feel that they are an acceptable substitute for sugar in a low-carbohydrate diet.

Sugar Alcohols and Low Carbohydrate Diets

Each low-carbohydrate diet works differently. While insulin is the primary loss mechanism, most low-carb diet designers have predicated the success of their diet on a chemical process that occurs in the body relating to blood sugar, insulin, and fat loss. Still, opinions vary widely in the low-carbohydrate community about whether or not sugar alcohols will affect low-carbohydrate diets. Ultimately, it appears that people are affected differently by sugar alcohols. Some can eat them and not experience a rise in blood sugar, while others feel they cause their low-carb weight loss to halt.

Some diets allow sugar alcohols, while others recommend that you avoid them altogether. Atkins, for instance, uses sugar alcohols to sweeten some of its diet foods, such as Atkins shakes and bars. Protein Power and PaNu, on the other hand, suggest avoiding sugar alcohols and products that contain them. Diets that do allow sugar alcohols recommend that you only eat them sparingly and watch to see how they affect you.

Sugar Alcohol Side Effects

While they are natural substances, some people experience side effects from sugar alcohols. The most commonly occurring side effects include flatulence, gastric upset, and diarrhea. Typically these side effects worsen the more you ingest. Minimizing or eliminating sugar alcohols from your diet will reverse any problems you have as a result of eating them.

The jury is still out on sugar alcohols and low carbohydrate diets. Anecdotal reports suggest that some dieters do just fine when they eat sugar alcohols, while others experience significant gastric distress, or discover that they are unable to lose weight on their diet. In the end, if you'd like to try foods containing sugar alcohols while on your low-carbohydrate diet, use them sparingly and monitor to see how they affect you.

Sugar Alcohols and Low-Carbohydrate Diets