sugar alcohols19 Apr 2004
You’ve probably noticed that low-carb diets are all the rage these days. You’ve probably also noticed that the food giants have noticed this as well. 10 years ago, slapping “low fat” on a food package solidified it as a hot seller. Today, it’s “low carb”. The requirements of “low carb” are being met increasingly creative and sometimes questionable ways.
First, “low carb” is being slapped on things where the carbohydrate content should be blindingly obvious. “Low carb” cheese. “Low carb” sausage. Sonic has a “low carb” chicken wrap. It’s got 13g of carbs, coming from.. well.. the flour tortilla. “Low carb” here is a bit of a stretch. It’s silly.
Second, you may have seen the phrase “net carbs” thrown around quite a bit. This is a measure of carbohydrate content as it pertains to the impact on your blood sugar. Carbohydrates like starches and sugars have an immediate impact on your blood sugar and insulin levels, two things that are very important in low-carb diets like the Atkins’ diet. Fiber, however, is a carbohydrate that the body is unable to metabolize. If food has carbohydrate content that is fiber, you can safely subtract this from the total, to get the “net” carbohydrates you really have to worry about. This is fine.
Slightly more complicated is the newfound popularity of an old food ingredient, listed on food packages as “sugar alcohols”. You can read a little about what these are on the wikipedia entry for them, which I have expanded a bit, and need to expand further.
In short, “sugar alcohol” is a term for any “polyol”, a form of carbohydrate that is similar to sugar, but chemically different. Sorbitol is a very common polyol, often used in chewing gum, while maltitol is a more popular new polyol. These are metabolized by your body differently as well, mostly in the lower intestine, via slightly insulin-independent means. Food manufacturers previously didn’t have to list these polyols as carbohydrates at all, until the FDA clamped down and forced them to (because, well, they are carbohydrates). This is why you may have noticed some low-carb candy went from having 3 carbohydrates to 20, with emphasis on the new “net carb” measurement.
While the glycemic effects on the body’s metabolism are still unclear, one thing is clear: polyols are carbohydrates, and they should be considered as such. They are still metabolized by the body and result in glycogen in the liver. If you’re aiming to maintain ketosis in the Atkins’ diet, these polyols will likely be counterproductive.
For more relaxed low-carbohydrate diets, some polyol intake in moderation is probably okay, but I wouldn’t overdo it. Especially because of their reputation for rather undesirable side-effects: bloating, cramps, and “a laxative effect”. They also have a reputation as “triggering” craving for real carbohydrates, or simply providing the excuse to totally overdo it. Eating low-carb requires a lifestyle change that is best served by giving up your predilection for indulgent, sugar-packed sweets – not finding replacements for them.
There hasn’t been much clinical testing of most of these polyols, on either their long-term side-effects or their metabolization by the body. The popularity of low-carb diets is certainly a good thing. But considering Big Food’s tendency to market anything and everything on the heels of a diet craze, I would cast a wary eye on the claims of any and all new “low carb” foods.