Traversing the keto diet with a sweet tooth can be tough, especially for beginners. Having to eliminate added sugars from one’s diet can be a difficult process, met with cravings, mood swings, and even withdrawals in some cases.

Fortuantely for all of us, there is a variety of different types of alternatives to sugar available to help cut down on carbs and keep our blood sugar levels low.

One of the drawbacks with all these options, is that not all of them are inherently keto-friendly. In this article, I’ll be laying out all the facts on isomalt, and how well it holds up against the other substitutes for the keto diet.

What Is Isomalt?

Isomalt is a type of sugar free sweetener that is characterized as a polyol, or sugar alcohol, which is widely used by those who are trying to cut back on sugar in their diets.

Isomalt is technically derived from sugar, but has a much lower calorie and carbohydrate count, while still being heat stable for baking and cooking.

Products that are made with isomalt are often comparably as sweet as sugar, and have the same texture and consistency as well.

It was first introduced in the 1960s, comprised of sucrose as a way to replicate table sugar with fewer adverse side effects.

It’s less frequently sold for consumer use compared to other sugar alcohols like erythritol and xylitol, but it is found in a plethora of packaged goods in most grocery stores and markets, including:

• Chewing gum
• Hard candies
• Toffee
• Baked goods
• Nutritional supplements
• Chocolates
• Cough Drops and Throat Lozenges
• Sugar-free drinks (sodas and juices)

Along with its heat stability for food processing and baking, isomalt retains water at a slower and less absorbent rate than other sugar alternatives, which makes it much less sticky, allowing it to be more versatile when used in different types of manufacturing. This is ideal for making sugar free products like candies, which need to be able to be sweet, but not stick to their outside wrappers. It’s also frequently used for cake decorating and sugar art, because of its non-sticky and stable temperature properties.

It’s often used with other sweeteners and sugars in a lot of products, because on its own it can vary from having roughly 45 to 65 percent of the sweetness as sugar.

Is Isomalt Keto-Friendly?

When it comes to sugar alternatives on the keto diet, carbohydrates are the biggest thing you should be looking out for, but some sweeteners also have a more hidden factor that can hurt your state of ketosis in the long run, and that is their effect on the body’s blood glucose levels, or glycemic index.

Even though some sweeteners have fewer carbs than sugar, their glycemic index values can still be high, resulting in blood sugar spikes, which can have adverse effects throughout your body, and even risk your state of ketosis. Fortuantely, Isomalt has few calories, and has little effect on blood sugar levels, making it a very keto friendly sugar alternative.

At a nutrient level, isomalt clocks in at about 2 calories per gram, with 0.2 to 0.4 grams of carbohydrates per gram. While this can still add up with large quantities, because isomalt is a sugar alcohol, these carbs don’t contribute to net carbs, making it perfectly keto friendly.

Benefits of Isomalt

• Doesn’t promote tooth decay

One of the biggest drawbacks of sugar is the problems it causes for our oral health. Sugar has been linked to cavities, tooth decay, and gingivitis, especially when consumed in large quantities over extensive periods of time (in other words, a standard American diet).

One of the cool things about Isomalt and most other sugar alcohols is that despite the fact that it’s derived from sugar, it actually has no corrosive effects on our teeth and gums. This makes it a great option for those who would like to cut down on sugar for both weight loss and dental reasons.

• Low glycemic index

Like other sugar alcohols, isomalt is only partially digested by the body’s enzymes after it is eaten, which classifies it as a low digestible carbohydrate.

Consuming isomalt instead of glucose or sugar therefore leads to a lower increase of blood glucose and insulin levels. By comparing the glycemic response of isomalt with sugar and glucose, isomalt yields a very low glycemic index value of 2. Glucose on the other hand tends to have a glycemic index value of 100, and table sugar has a glycemic index value of 68.

This makes isomalt a great option for both those with diabetes who need to keep their insulin in check, and those trying to maintain a healthy state of ketosis by not rapidly fluctuating their blood glucose levels.

• Promotes weight loss

As with most low carb, low calorie, and low glycemic sugar substitutes, isomalt can promote weight loss in a pretty big way.

Isomalt is roughly only half of the calories per serving compared to normal table sugar, because the body can technically only utilize roughly 50% of the energy it provides, due to those enzymes as mentioned above.

Studies have shown that even just small changes in calorie reduction can contribute to weight loss over time, and because isomalt can help a lot of formerly sugar-dependent people cut down on carbohydrates, it can contribute to activating the weight loss benefits of the keto diet too.

• Behaves like fiber

Isomalt and other good sugar alcohols behave like fiber in the body because of how they are digested. Even isomalt and those other sugar alcohols are technically classified as carbohydrates, because of how they are passed through the digestive system without being absorbed, they effectively can be treated the same as fiber when calculating net carbs.

For this reason, a lot of low carb products like quest bars are able to call themselves keto-friendly, despite having high total carbs and little fiber, because the carbs that they do contain, largely come from sugar alcohols instead of just plain sugar or worse sweeteners like dextrose and maltodextrin.

• No aftertaste; enhances flavors

One issue a lot of people have with sugar substitutes is aftertaste and the effects the sweeteners have on their food’s flavors. Sucralose, or splenda, is a big contributor to this effect, as well as a few other sugar alternatives.

Fortunately, isomalt and most sugar alcohols do not have this aftertaste effect, and in fact they are used to enhance the flavors of foods in a lot of recipes.

A recent study found that because of isomalt’s lack of cooling effects and chemical structure, it’s great when used to enhance the flavor transfer of ingredients in baked goods such as low carb cakes and pastries.

Side Effects of Isomalt

• Not currently FDA approved

Isomalt is not currently approved as GRAS (generally recognized as safe) by the Food and Drug Administration, or FDA (As of 2019), but it is allowed in food manufacturing and producing by the FDA due to recent petitions for approval and due to the fact that other sugar alcohols are currently recognized as safe.

While at first glance this may seem like a pretty big concern, I don’t personally think it’s a huge drawback compared to the other two. This is largely because any produced and manufactured foods and drinks that contain isomalt still have to go through rigorous FDA scrutiny to be approved for United States consumption, so they’re generally safe. This doesn’t apply to other countries however.

• Can cause diarrhea

Like a lot of sugar substitutes, isomalt unfortunately can result in indigestion, nausea, bloating, and diarrhea if it is consumed too frequently and in too much of a quantity.

This happens primarily because of the fact that isomalt is known to attract water from the intestine wall, which has been known to cause diarrhea when consumed in excess via osmosis.

Generally, most healthy people can handle up to 50 grams of isomalt per day, so I don’t think it’s something you’ll have to really worry about that much if you’re working right within the net carb guidelines of the keto diet.

• Potential Allergies

Allergies for isomalt and other sugar alcohols can either present themselves in the form of digestion intolerances (similar to a condition like lactose intolerance), or in the form of traditional allergic reactions such as breaking out in hives, itchy skin, sneezing, and having trouble breathing.

If you’re allergic to honey or specific types of fruit, there’s a chance you may also suffer from an allergy to sugar alcohols, so eating products that contain isomalt should be met with some caution until you know exactly how your body will react to it.

Isomalt vs Other Sweeteners

• Monk Fruit

Monk fruit is definitely my favorite option out of all alternative sweeteners that are acceptable for the keto diet. As a substitute, it is about 100 to 250 times sweeter than table sugar.

Because of this, a little bit of monk fruit extract or powder tends to goes a much longer way compared to something like isomalt, which has only 60-70% of the sweetness of sugar. Even more, it’s zero carb, so you can use as much of it as you need compared to other sugar alcohols that might bring up your net carb count if they’re mixed with other materials.

• Sucralose

Sucralose, which is more commonly referred to as Splenda by most manufacturers and restaurants, is also fairly common when it comes to alternative sweeteners, but unfortunately it isn’t the best option for maintaining a state of ketosis.

When used as a sweetener by itself, sucralose has zero calories and zero glycemic index, making it a great keto friendly option. However more commonly but when it is sold as a powder (splenda packets) or mixed into prepackaged foods, it likely will be mixed with other sweeteners that can easily add to your overall carb counts and even still spike your blood sugar in some cases.

• Stevia

Stevia, which is an extract derived from an extract of the leaf of the stevia plant, is one of the most popular keto-friendly substitutes. This is largely because stevia is cheap to make, and is widely marketed as a natural, low carb sweetener. It’s pretty easily available in most stores, online markets, and coffeeshops as well.

Stevia does have some digestion related side effects similar to isomalt so it’s best to use it with caution. However generally stevia is pretty widely accepted by the keto community.

• Xylitol

Xylitol, like isomalt is another type of sugar alcohol that is often used by a lot of keto dieters. Generally, xylitol is great to use on the keto diet in moderation, but when it comes to sugar alcohols I’d honestly recommend erythritol over xylitol or isomalt when it comes to frequent use and using it in large quantities for certain recipes

Another drawback of xylitol is that it doesn’t have as many benefits as other sugar alcohols, and does come with some side effects like gastrointestinal problems, and negatively impeding the overall weight loss process.

• Maltitol

Maltitol is absolutely one sweetener that I think should be avoided whenever possible if you’re sticking to a keto diet.

While maltitol might have a slightly lower glycemic index value than your average table sugar, it’s still derived from malt starch, and is technically classified as a carbohydrate – so by using it in your keto cooking,it will likely surge up your net carb counts fairly quickly.

While maltitol does have some other cool benefits such as also being low in calories and having no adverse effects on dental health, there are still a ton of other awesome keto-friendly sweeteners available with similar benefits that don’t end up risking your state of ketosis.

• Erythritol

Erythritol, like isomalt is a pretty popular keto-friendly sugar alcohol.

Erythritol however distinguishes itself from other forms of sugar alcohols because it occurs in nature more prevalently, and has a much lower glycemic index value (similar to isomalt).

Erythritol also brings in way fewer calories that other sweetener alternatives, which makes it more effective as a sugar replacement for those who are trying to watch their calorie intake, as well as for those who want to cut down their sugar intake for general caloric deficit driven weight loss.

• Maltodextrin

I am a little bit conflicted when it comes to this one. Maltodextrin is definitely better for you than table sugar, but I personally wouldn’t say it’s a particularly keto-friendly alternative sweetener.

Maltodextrin is perfectly fine to eat in moderation, and it can be hard to avoid with a lot of sugar-free products containing it. Be that as it may, it’s still important to know that maltodextrin also has a high sugar content and high glycemic index value, which means that it can pretty easily contribute to net carbs and has a lot of potential to spike your blood glucose levels.

• Allulose

Allulose is technically classified as a monosaccharaide, which is a rare type of natural sugar.

As an organic substance, it occurs in nature, and is typically found in dried fruits such as figs, raisins, and jackfruit, but really only in trace amounts.

When allulose is produced for human consumption, it is usually processed into an extract, so that it can be used as a substitute for sugar. Like isomalt, allulose is generally 70% of the sweetness as sugar, and does have some slight amounts of carbohydrates per serving.

Final Thoughts

As you can see, isomalt is a great keto-friendly option when it comes to alternative sweeteners, but there are still other sugar alcohols and substitutes that I personally prefer.

When figuring out the right way to beat your sweet cravings, it’s important to look at all of the nutrition facts available. Because isomalt is usually eaten as a part of pre-packaged and sugar free foods, you’ll want to check to keep an eye on carb counts, specifically carbs from sugar vs sugar alcohol, so that you can accurately decide if a product is keto-friendly enough for your macro limits.

Do you have any favorite recipes with Isomalt? Drop a comment below, I’d love to learn more ways to use it in my keto cooking.