Sugar-alcohols (or “polyols”) are one of those really weird food items that are difficult to classify — and there’s a lot of confusion about whether or not they “count” towards our calorie and carb goals. Good news though — you’re about to become an expert!
First, and this needs to be really clear, I’m not referring to SUGAR. I’m referring go Sugar-Alcohols. This is what they look like on a nutrition label — note that they are SEPARATE from sugar:
So if they’re not sugar, what are they?
The molecules are actually a hybrid between a sugar molecule, and an alcohol molecule. But they are technically neither. We don’t have a good way to classify them.. so the FDA calls them a “carb”.. even though they’re really not. (This is a case of the FDA being forced to classify them, even though they really belong in their own macro-nutrient category). Despite the name, they contain no ethanol, by the way, so they are safe for alcoholics.
Sugar-alcohols are commonly used in things like sugar-free candy and other sweets. Since they’re not technically sugar, they can be used to help sweeten foods, while still allowing the manufacturer to claim that the food is “sugar free”. In this case, however, sugar-free doesn’t mean calorie-free. Sugar-alcohols have about half the calories of normal sugar… sometimes even less than that. So while they’re better for you, calorically, they aren’t “free” from an energy perspective.
They also aren’t completely artificial — they actually appear naturally in many fruits and vegetables. There are also a huge variety of them on the market (Xylitol, Erythritol, Sorbitol, Malitol, mannitol, isomalt, lactitol and hydrogenated starch hydrolysates — just to name a few!!) — each has their own distinct taste, and various pros and cons that are beyond the scope of that I want to get into here.
Also worth noting — some well known sweeteners, like Stevia and Truvia are sugar-alcohols. (Stevia and Truvia are both Erythritol, in fact — which has 70% of the sweetness of sugar, with only 5% of the calories — and comes from a plant leaf!!)
Can sugar-alcohols make you gain weight? Do I count them?
Yes and no.
Purely from the standpoint of a traditional diet, they do have (some) calories, and calories are the cause of weight-gain. So in that respect, yes. They can make you gain weight, and you should absolutely count them in your daily numbers — even though the total impact is probably negligible.
That said, science is a little bit split on how much of the calories from sugar-alcohols actually matter. Because they digest so incredibly slowly, many studies indicate that at least SOME of the calories from sugar-alcohols are ejected from your body before they even have a chance to be processed. I’m more of the opinion that if you put in a calorie in your body, you should assume it was processed — just to be on the safe side. It also depends on the type of sugar-alcohol. As hinted above, some of them have more calories than others, due to the rate of digestion.
However, if you are doing a keto-based diet, like Atkins, the protocol actually tells you that you can ignore all carbs (not calories) from sugar alcohols because sugar-alcohols do not cause an insulin reaction (your body doesn’t respond with that surge of energy that normal sugar provides — because they digest very, very slowly) — and preventing insulin reactions is the sole purpose for the carb limitations on keto. (Keto-based diets allow you to ignore carbs from fiber for exactly the same reason!)
Are sugar-alcohols bad for you?
The only real problem with sugar alcohols is that they can cause digestive problems when consumed in large amounts (more than about 20g to 30g). Since the body cannot digest most of them, they travel to the large intestine where they are metabolized by the gut bacteria. If you eat a lot of sugar alcohols in a short period of time, this can lead to symptoms like gas, bloating and diarrhea.
Other than that, the downsides are pretty minimal!! So as long as they’re consumed in small amounts, they’re a reasonable alternative to other types of sweeteners.