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!!)
Are all sugar alcohols the same?
NO!!! Some are actually nearly as bad as sugar (Malitol), and some have no affect at all (Stevia). Everything else is somewhere in the middle (And there are dozens upon dozens of different kinds of sugar alcohols).
Are Aspartame and Sucralose sugar-alcohols?
No. They are chemical sweeteners and not in the same family. You can learn more about aspartame and sucralose, here.
Can sugar-alcohols make you gain weight? Do I count them?
Yes and no.
First, 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.
Second, as mentioned above, different sugar alcohols affect our blood sugar very differently — both depending on the sugar alcohol itself, what you ate along with it, and your individual digestive system! Some are nearly as bad as sugar, and some have no impact at all.
So while the traditional rules of Keto say “subtract all sugar alcohols”, my experience is that people who do that, and then eat them in large volume, tend to stop losing weight. They aren’t free.
Are sugar-alcohols bad for you, otherwise?
Other than the fact that some are nearly as bad as sugar (while some are perfectly fine), the only other 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.
So how do I know which ones are okay and which ones I should avoid?
First, the only way to know FOR SURE is to use a blood glucose meter to check your glucose levels after eating them. There is no one answer for every person, and what YOU respond to me be different than everyone else.
But as a general rule, you should pay attention to the glycemic index of the different sugar-alcohols. Here are a few (the higher the glycemic index, the worse it is for you). Note that I put “sugar” (glucose, fructose) on the chart as a point of reference, so you can see how it compares. Note that if you are doing keto (CarbX), I would avoid anything with a glycemic index over 0. If you’re doing MacroFit (Macro Counting), I would avoid anything over 10.