Is Sugar Alcohol Keto?
Even keto dieters need a little sweetness in their lives! I know I do.
But since white sugar is just pure carbs, you have to skip all the regular forms of sugar on Keto (even honey, maple syrup, coconut sugar, and agave are out).
And as a result, many people use sugar alcohols (which are low-calorie sweeteners) instead to satisfy their sugar cravings.
According to Registered Dietitian Christin Sehner, RD., “Sugar alcohols (eg, sorbitol, mannitol, xylitol) are reduced-calorie sweeteners that still provide calories (approximately 2 kcal/g) yet are less energy dense than natural sources of sugar due to their incomplete metabolism.”
Don’t worry, they’re not the same as the alcohol you drink! Chemically speaking, sugar alcohols are sugar molecules with an alcohol group attached to it. (Plus, for people on keto alcohol is likely to kick you out of ketosis, at least briefly!)
The problem for us Keto folks is that not all sugar alcohols are equal: some of them can cause digestive issues, others can make your sugar cravings worse, and a few may even kick you out of ketosis. Watch this!
Plus, some actually do contain some carbohydrates, according to Dr. Steven C. Simper, MD. “U.S. labeling laws allow manufacturers to use the terms ‘sugar free’ or ‘no added sugar’ on the labels of products made with polyols, giving the illusion that the product has no carbohydrates. It is easy to mistakenly think that eating ‘sugar free’ foods does not count towards your daily food intake, but some products may contain significant amounts of carbohydrates. It is important to check the food label.”
Below, we’ll go through all the common questions you might have about sugar alcohols (what are sugar alcohols, common sugar alcohols, why or why you shouldn’t use sugar alcohols, and alternatives to use instead).
But if you’re looking for a quick answer…then here’s the sugar alcohol Keto dieters tend to do well with, along with the best sweetener, in general, to use on Keto:
Best sugar alcohol for Keto: Erythritol
Best Keto sweetener: Stevia
What are sugar alcohols?
Sugar alcohols (also known as polyols) are a type of sweetener commonly used in low carb, Keto, sugar-free, or diet-friendly foods.
Sugar alcohols occur naturally in foods like berries and fruits. But they can also be manufactured from sugars.
The most common sugar alcohols you’ll come across are:
And you’ll have seen various ones in low carb, sugar-free, or Keto recipes as well as pre-packaged sugar-free drinks and snacks.
But the most important question is: do sugar alcohols prevent ketosis?
Do sugar alcohols kick you out of ketosis?
It depends. Not all sugar alcohols will kick you out of ketosis.
According to Keto Oncologist Jocelyn Tan, M.D., “Sugar alcohols technically are natural compounds and are a form of digestible carbohydrate….Commonly present in food additives to give sweetness, they don’t bring up blood glucose as much and don’t stimulate the secretion of insulin.”
Sugar alcohols act as low-calorie sweeteners because our bodies don’t absorb all of the carbs they contain into your bloodstream. That means they don’t raise your blood sugar levels like regular sugar does.
But different sugar alcohols behave differently…some are absorbed more and will, therefore, raise your blood sugar levels more. So if you have too much, it can kick you out of ketosis.
Plus, some sugar alcohols have pretty nasty side effects if you consume too much of them…
“In some people sugar alcohols can cause bloating, flatulence, and diarrhea,” according to Nutritionist and Certified Personal Trainer Brad Sly. “This is because the sugar alcohol is not completely absorbed in the digestive system and this causes fermentation to occur in the intestines.”
And too much of them can undo all your hard work. “You can also still gain weight when eating foods that contain sugar alcohol, especially if you eat them in excess,” according to Registered Nurses Sue Cotey, RN and Andrea Harris, RN.
Let’s take a look at them in more detail…
Check out this video for how sugar alcohols affect low carb diets:
Types of Sugar Alcohols
Uses: Glycerol (also called glycerin) is a mildly sweet compound that isn’t typically used as a sweetener but instead as a food additive for bulking and adding texture (glycerol is often added to help foods stay moist). (1) You might also find it in liquids like vanilla extracts as well as cough syrup. (2)
- It only has a small effect on your blood sugar levels (if your body has a normal, healthy insulin response).
- It has no adverse effect on your dental health.
- It’s water soluble.
- It tastes less sweet than sugar but has more calories, making it easy to overuse if you’re not watching your intake (which can significantly increase your daily calorie count).
- Glycerol may cause a change in your blood sugar levels. (3)
Uses: Isomalt is a sugar alcohol that’s usually made from beets. It’s roughly half the sweetness of regular sugar and also contains half the calories. (4)One of the main uses of isomalt is in baking because it adds plenty of bulk that doesn’t break down or lose its sweetness when heated. Isomalt is usually found mixed with other sweeteners such as sucralose to make it sweeter in taste. It can also be found in foods like sugar-free cough sweets. (5)
- It has a minimal effect on your blood sugar levels.
- It isn’t bad for your teeth.
- It can wreak havoc on your gastrointestinal tract if consumed in large quantities (typically more than 50g a day). (6)
Uses: Lactitol, like isomalt, is half the sweetness and has half the calories of regular sugar. It’s a prebiotic that could help improve your colon health because most of it isn’t digested until it reaches your colon. (7) It’s used as a low-calorie sweetener in many baked goods as well as a treatment for constipation because of its laxative effects. (8)
- It doesn’t negatively affect your dental health.
- It could boosts the numbers of good bacteria in your gut.
- It has a strong laxative effect, and studies suggest that staying under 70 grams per day of lactitol. (9)
- Other digestive issues such as bloating, stomach cramps, and diarrhea. “Although the strategyof substituting lactitol for sugar in foodstuffs is undoubtedly good for teeth, and the pancreas, it may not produce socially acceptable bowel habits.” (7)
Uses: Maltitol is a very commonly used sugar alcohol. You can find it as a major ingredient in sugar-free chocolates and ice-cream. It’s about 90% as sweet as regular white sugar and it reacts very similarly to sugar (except it doesn’t brown) with only three-quarters of the calories. (10)
- It’s not bad for your teeth.
- It behaves almost just like sugar does so it’s easy to use as a sugar-free substitute in recipes.
- It can raise your blood sugar levels. While maltitol doesn’t raise your blood glucose levels as high as regular sugar (dextrose), the increase is still noticeable. (11)
- It can cause mild digestive issues like gas and bloating. (12)
Mannitol is a sugar alcohol found naturally in fruits and vegetables. It has 40% fewer calories than regular sugar but it also tastes 50% less sweet. It’s usually used in the same way as powdered sugar, to coat hard candy and chewing gum.
- It has a very low glycaemic index (only 2 out of 100, and sugar is 65), meaning it doesn’t have a strong effect your blood sugar and it’s suitable for diabetics.
- It can’t be processed by the bacteria in your mouth, so eating it won’t cause tooth decay.
- It’s used for various medical applications like treating renal failure, cystic fibrosis, head trauma and as a laxative for children. (13)
- It’s not really a useful replacement if you’re keeping an eye on your daily calorie intake. Although it’s lower in calories, it also tastes less sweet – so you have to add more to get the same sweet taste.
- Some people may be allergic to it, and experience rashes and dizziness as result of eating it.
- Eating too much of it can cause diarrhea, nausea, and cramps. And consuming very large amounts can cause serious health issues like renal failure and heart failure as mannitol is an osmotic agent.
Polydextrose is not technically a pure sugar alcohol. It’s made by combining sorbitol and dextrose (aka corn sugar). Polydextrose is mostly fiber and only has a mild sweetness compared to regular sugar. It’s usually used in baked goods to give them a bit more bulk and fiber.
- It’s good for your colon health because it has a similar effect to vegetable fiber. (14)
- It slows down your blood sugar response to carbohydrates.
- It’s not bad for your teeth.
- It produces a laxative effect if too much is eaten. (15)
Sorbitol is a sugar alcohol that naturally occurs in many fruits like apples and pears but is typically made by extracting it from glucose. It has 60% the sweetness of regular sugar and two-thirds of the calories. (16) It’s often used in chewing gum, toothpaste, and mouthwashes as it naturally produces a cooling effect in the mouth after you eat it.
- Doesn’t impact your blood sugar levels. (17)
- It has no detrimental effects on your dental health.
- One side effect of sorbitol is that it can cause bloating and gas. (18)
- It has a powerful laxative effect and can cause severe diarrhea. (19)
- Has a cooling effect in the mouth which can affect the taste of foods made with sorbitol.
Xylitol is made of plant fiber and is about as sweet as regular sugar but with only two-thirds of the calories. It isn’t just used to sweeten foods – you can also find it in many cosmetics and medicines.
- Xylitol only has a small effect on your blood sugar levels. (20)
- Xylitol is good for your dental health and can prevent cavities. (21)
- Xylitol could potentially prevent osteoporosis by increasing bone density. (22)
- Xylitol could potentially increase the amount of newly synthesized collagen and thereby lead to better skin appearance. However, this study has only been done on the skin of aged rats. (23)
- Xylitol could be a useful prebiotic fiber that feeds your gut bacteria. (24)
- It has a laxative effect.
- It’s toxic to dogs and can kill them. So keep products containing xylitol out of reach of your furry friends. (25)
Erythritol has almost zero calories and is about three quarters the sweetness of regular sugar. Because it has a slightly minty and cooling taste, it’s often combined with other low-calorie sweeteners. For example, Swerve is a combination of erythritol and oligosaccharides. It’s great for baking with.
- It has the smallest laxative effect compared to other sugar alcohols (26).
- It has no negative effect on dental health, with some studies showing it can actually prevent tooth decay. (27
- It has no effect on your blood sugar or insulin levels (28).
- Eating large amounts (over 50g) can cause an upset stomach, nausea and (in some cases) hives. (29)
- Has a slightly minty taste or cooling effect when eaten.
What Are The Best And Worst Sweeteners To Use On A Keto Diet?
If you’re going to use a sweetener to help you manage your sugar cravings, or if you just want your keto desserts to taste right, I recommend Erythritol or Stevia.
Erythritol (which you can purchase on Amazon here) causes less digestive issues than other sugar alcohols and it’s easy to use in baked Keto recipes.
Stevia (which you can buy on Amazon here) is a herb, also referred to as “sugar leaf”. And sweeteners made from an extract of Stevia leaves are a great low carb alternative to sugar alcohols.
Why? Because Stevia contains zero carbs, zero calories, and no nutrients, so you won’t have to worry about counting it as part of your daily carbohydrate allowance. Plus, you won’t experience any bloating or other digestive distress, unlike with sugar alcohols!
The main issue with stevia is that it can leave a bitter aftertaste (and some people taste it more than others). One great option is to mix Erythritol with Stevia and to use strong flavors like cinnamon in the baked goods. This helps to cover up any bitterness in the stevia.
Want to give these keto sweeteners a try? Take a look at these Keto desserts recipes!
And if you have any questions about sugar alcohols or how to use keto sweeteners, then head over to our keto diet forum.