The Best and Worst Low Carb Sweeteners

Most people that start a keto diet plan find that they have some intense cravings for sugar in the beginning, but will dissipate after a few weeks. Even the seasoned low carber will tell you that they have cravings every once in a while, sometimes burning inside them so deep they want to give up to temptation. That’s where sweeteners come in, where you can make or bake things you usually can’t eat.

Of course, you will have to watch out because most things that say “carb free” actually still contain carbs. Make sure you take the net carbs of any impacting sweetener into consideration when tracking your macros.

As a general rule of thumb, it’s always best to try to avoid sweeteners in the beginning. They’re well known to cause cravings and some may stall your progress with over-use. Stay strict and try to only occasionally consume sweet treats when you are on a low carb diet.


Types of Sweeteners

In general, there are a few classifications of sweeteners. There are natural sweeteners, sugar alcohols, and synthetic sweeteners (or artificial sweeteners). There are a few others that aren’t exactly classified in these categories (like glycerin based sweeteners) but they are quite uncommon and rarely used, so we’ll skip going over them.

For a ketogenic diet, I personally suggest sticking with erythritol and stevia (or a blend) because they are both naturally occurring, don’t cause blood sugar or insulin spikes, and sweeten just perfectly. When used in combination, they seem to cancel out the aftertaste that each has, and work like a charm.

When you purchase sweeteners, make sure to take a look at the ingredients on the packaging. You normally want the pure sweetener, rather than having fillers such as maltodextrin, dextrose, or polydextrose which can cause spikes in blood sugars. Fillers can also add unnecessary carbs to your sweeteners, so it’s best to stay away.

Below we’ll look at the most common of all the different types of sweeteners we encounter, and which are the best to choose.


What is GI?

Beside each sweetener’s name, you will see “GI” and then a number. This refers to the Glycemic Index, which measures how much your blood sugar is raised by a certain food. Many sweeteners are 0 GI, meaning they don’t raise blood sugar. The baseline is insulin, which measures up at 100. Typically you want to use the sweeteners that are lowest in GI, but may find it more beneficial (taste wise) to use a mixture.

Below you’ll find an overview of our list and their respective glycemic index, carbs, and calorie counts. If you scroll to the bottom of the page, you’ll find more on sweeteners you must avoid on a low carb ketogenic diet.

Sweetener GI Type Net Carbs (Per 100g) Calories (Per 100g)
Stevia 0 Natural 5 20
Inulin 0 Natural 1 150
Monk Fruit 0 Natural 0 – 25 0 – 100
Tagatose 3 Natural 35 150
Erythritol 0 Sugar Alcohol 5 20
Xylitol 13 Sugar Alcohol 60 240
Maltitol 36 Sugar Alcohol 67 270
Sucralose 0-80 Artificial 0 0
Aspartame 0 Artificial 85 352
Saccharin Variable Artificial 94 364
Table Sugar 63 Processed 100 387

Natural Sweeteners

Stevia – GI: 0

Stevia is a herb that is commonly known as the sugar leaf. The completely nutrient-free extract has grown tremendously in popularity over the last few years and is used very commonly now.

Stevia can be quite good for us. It has been shown to reduce blood pressure slightly, lower blood glucose and insulin levels in diabetics, and has had great results in animal testing for anti-inflammatory purposes.

When purchasing, go after liquid based stevia. Typically this is raw powdered stevia mixed with a solution that keeps it pure. If you purchase powdered stevia, it is commonly mixed with other sweeteners that can cause problems (like hidden carbs).

stevia

Recommendation: Use it! It’s a great additive sweetener on a keto diet for many occasions and can even have a positive health impact. If using in cooking, pair with other sweeteners as in liquid form it won’t give you the additional “bulking” you need.


Inulin – GI: 0

Not to be confused with insulin, inulin is a natural based sweetener that is commonly extracted from chicory root. According to studies, we can absorb some of the inulin we digest – so even though the packaging may tell you otherwise, it may not be true.

Inulin does a great job as a mixture with other sweeteners. It adds sweetness, can caramelize like sugar, and typically doesn’t add any after-taste like you may find with others.

Even though this shouldn’t cause any gastric distress within normal daily doses (studies show about 20 grams), it can have a laxative effect if over-consumed.

inulin

Some studies have even shown it to have pre-biotic effects and can help our digestive systems in a normal manner when consumed in normal doses.

Recommendation: Use sparingly to mix into other sweeteners (like erythritol) to reduce after-taste and to increase cooking ability. In terms of a ketogenic diet, some studies also show a slight absorption of it, so it may have more net carbs than thought.


Monk Fruit – GI: 0

Also known as Luo Han Guo, monk fruit is native to China. It’s extremely sweet (about 300 times as sweet as sugar) and has been used as a traditional medicine to treat obesity and diabetes.

It’s quite hard to find and can be quite expensive to purchase in its pure form. Usually, in bulk, you are purchasing mixes with other sweeteners inside, many of which are high glycemic index and are not worth eating. In most cases, it’s best to avoid this.

MonkFruit

Recommendation: Skip it. Although it’s a fantastic sweetener, it’s very hard to come by in the raw form and can be quite costly when found. Many of the common branded monk fruit will contain carbs.


Tagatose – GI: 3

Tagatose is a monosaccharide (simple sugar) that naturally occurs in dairy, fruits, and cacao. It’s got a different arrangement of atoms than sugar does, so it’s metabolized differently than sugar. It does have a mild cooling effect, similar to erythritol but it does caramelize similarly to sugar (while erythritol does not). It’s a smaller glycemic index than Xylitol and is not toxic to dogs, but it is a little bit harder to find.

Tagatose has a pretty low glycemic index, so it only has a small effect on blood sugar levels and can be used with other sweeteners in a low carb diet. It also has some health benefits attached to it like increased HDL cholesterol (read more about cholesterol) and a prebiotic health promoting healthy gut bacteria.

Tagatose

Recommendation: Use it sparingly with other sweeteners. It can pair well with lower glycemic index sweeteners in moderation but it does contain about 35g carbs per 100g so be careful with the amount that you use.


Sugar Alcohols

Erythritol – GI: 0

Erythritol is typically found in fruits and vegetables and is commonly extracted from corn. The great thing about it is that it does not affect blood sugar and has very few calories.

We can consume a good amount of it, at about 1 gram of the sweetener for 2.2 pounds (1 kilogram) of body-weight. Usually, sugar alcohols can cause discomfort because our body does not have the enzymes to break them down, leaving the bacteria in the large intestine to excrete it. With erythritol, it only gets to the small intestine and is eventually excreted mostly in urine. That said, some studies have shown there to be slight stomach discomfort when consumed in large quantities.

erythritol

Because of this, we really don’t see much of an effect when it comes to the keto diet. This is one of the primary sweeteners I use to make baked goods and to sweeten things with.

According to some recent studies, erythritol does not change blood sugar or insulin in healthy individuals. It has also been shown to not feed bacteria in the mouth, so is slowly becoming a good alternative to sugar for lack of cavities and tooth decay alone.

Recommendation: Use it! It’s almost completely excreted through urine and causes very little gastric distress. Although it can have a slight cooling aftertaste, when combined with other sweeteners it is not very noticeable.


Xylitol – GI: 13

Xylitol is a naturally occurring sugar alcohol that is usually found in fruits and vegetables. It’s not very nutrient dense (like stevia), and is relatively low in glycemic index so it does not dramatically affect blood sugar levels. Many people enjoy this sweetener because it is very close to the sweetness of sugar and can easily be substituted.

Among other things, xylitol can help with dental health by starving the bad bacteria in the mouth. It’s commonly found in many of the whitening chewing gum out there. It has also been linked to increasing collagen production and may help promote good bacteria in the gut.

xylitol

Stomach discomfort is one of the biggest complaints from this sweetener and has been shown that larger than 65 grams a day can cause diarrhea.

Note/Warning: Xylitol is extremely toxic to dogs and can be lethal in just small doses. Make sure if you have animals and you are using this, be extremely careful to keep it out of reach.

Recommendation: Use sparingly. Although this is a great sweetener and can be used in almost an exact replacement of sugar, it can cause gastric distress when over-eaten. It is also extremely harmful to dogs, so if you’re an animal lover, it may not be best to have around.


Maltitol – GI: 36

Maltitol is very commonly used in sugar-free products as it is very similar to sugar. If the packaging says that a product is sugar-free, you will most likely find maltitol on the ingredient list. It cooks and tastes very much like the real thing, and is only half the calories of actual sugar. The downfall of this is that it has quite a large glycemic index – meaning it spikes blood sugars.

However, due to the current laws we have, many products are allowed to calculate these out of the net carb counts and many people are secretly consuming hidden carbs. This one is best to avoid.

Maltitol

On a low carb diet, it’s always best to be skeptical of products using this. Many times we see people over-consume on products using maltitol, which can lead to a slowing of weight loss.

Many also complain of the laxative effects maltitol has. It’s commonly associated with stomach issues including bloating, diarrhea, and abdominal pain.

Recommendation: Skip it. Although it’s one of the most commonly consumed sugar alcohol, it has quite a high glycemic index and can cause a lot of gastric distress. Not to mention many people complain about it kicking them out of a ketogenic state.


Other Sugar Alcohols

There are many other sugar alcohols out there, but most of the others should be avoided. This includes sorbitol, lacitol, glycerol, and isomalt due to their effect on our blood sugar levels. You should always be aware of products that say they are zero carb or sugar free as they usually contain one of the higher GI sugar alcohols and will spike both insulin and blood sugars.

Note: Some sweeteners combine erythritol with oligosaccharides. These are a short-chain carbohydrate that is derived from fruits and vegetables like chicory root (similar to inulin). Oligosaccharides are an indigestible carb, so they’re similar to dietary fiber. They do have a glycemic index but depends on which you use and how it’s processed. A very common sweetener, Swerve, uses these in their formula to help provide some structure to the erythritol.

There are some health benefits, like the promotion of good gut bacteria. Some studies also showed a reduction in cholesterol and triglycerides when using oligosaccharides. You shouldn’t have to avoid these, but it’s always best to eat in moderation. Luckily, they are usually used in small quantities alongside a 0 glycemic impact sweetener, so together it will have little impact on blood sugars.

When on a ketogenic diet, you want to try to keep these blood sugar and insulin spikes to a minimum or you may see some weight loss stalls. Over-consumption of any sweetener can lead to cravings of regular sugar and make the transition to a low carb diet even harder than it is. Try to consume sweeteners in moderation to help control your cravings and progress.

Recommendation: Be very cautious of products touting to be low or zero carbs. They typically contain a sugar alcohol that has a high GI which should be avoided.


Artificial (Synthetic) Sweeteners

Sucralose – GI: Variable

Before we talk about sucralose, there is a slight controversy about the glycemic index. There are many sources claiming many different numbers, but on an average, we see that it’s about 80 GI in powdered form (Splenda). The bad part about this is that it’s higher than sugar and can cause big spikes in blood sugar – so you should try to avoid the powdered form for the keto diet.

The good part about it is that it typically can be found in liquid form too. This goes an extremely long way when it comes to sweetening things: it’s 600 times sweeter than sugar.

sucralose

The glycemic index for pure liquid sucralose is 0, so you can use this as you would stevia. In liquid form, it has little to no effect on blood sugar levels. It’s great to use in combination with less sweet “bulking” sugar substitutes (like erythritol) to bake with.

The most commonly used brand of this product is Splenda (which is paired with other high GI sweeteners) and was extremely rampant in the low-carb communities in the early 2000’s. Definitely avoid using any powdered forms of this sweetener as it contains other filler agents like maltodextrin with a much higher glycemic impact.

Recommendation: Use sparingly (in liquid form) and in combination with others. For cooking, the liquid doesn’t do what you need it to do – add “bulk”. So add it to other sweeteners to spruce them up. If using by itself, it may be a better option to use stevia if you prefer natural sweeteners.


Aspartame – GI: 0

Aspartame is probably the most controversial sweetener of all. It’s been behind many stories of multiple sclerosis, systemic lupus, methanol toxicity, and blindness among many other things. It’s a very common sweetener that is used in many low carb products and diet drinks out there.

Even though the negative claims haven’t been replicated in studies over the last 40 years (it’s one of the most thoroughly studied sweeteners), it may be best to stay away from this one as there are better alternatives. It’s always better to be safe than sorry.

aspartame

It can be used in many different cold dishes, but at higher temperatures, aspartame can break down during baking and cause bitter and strange aftertastes.

Recommendation: Avoid it. Although there is much controversy around this (and nothing has definitively been proven), there are much better sources of sweet out there and it’s always best to be safe than sorry.


Saccharin – GI: Variable

First showcasing over 150 years ago, this synthetic sweetener is one of the oldest around. This is not very commonly found or used anymore, as the popularity for saccharin has gone down significantly. It is still in the top 3 synthetic sweeteners, which is why it is included but is dwindling in usage.

In the 1970’s, all saccharin products had to place a warning label that it may induce cancer in man or animals. This was then removed during 2000, when the animal based testing couldn’t ethically be done on humans. There have been reports of many short-term side effects, but none that have been replicated in studies.

saccharin

Other than the controversy surrounding saccharin, another reason to avoid this is during the cooking process, it can cause an extremely bitter aftertaste. Since many of us are creating baked goods, it usually leaves an unpleasant taste.

Recommendation: Avoid it. Since its dwindling in popularity, it’s much easier to find other commonly sourced sweeteners around.

Overall, it’s always best to go with pure sucralose and stevia as your sugar alternatives – not only for the taste and versatility but also the calorie counts and carb counts. Here’s a look at the nutrition info on the above sweeteners.


Overview of Sweeteners

Below, you’ll find a graphical representation on what to eat when choosing a sweetener for your recipes. It’s best to stick to low or no glyemic index sweeteners with fewer calories. As you can see, erythritol, stevia, and liquid sucralose are our top recommendation for sweeteners. You can always choose different sweeteners to get a different texture and taste when making recipes.

Try to be conscious about which sweeteners you use and the effect that they will have on your blood sugar levels. Always be very careful about low-carb products that are pre-made as they usually have some form of high GI sweetener used in them.

best and worst sweeteners for ketogenic diet


Sweeteners to Avoid on a Ketogenic Diet

Avoid High Fructose Corn Syrup

High fructose corn syrup is a sweetener that’s highly processed and derived from corn. It became popular in the 70’s when corn prices were low because of government subsidies. It contains simple sugar and fructose, which have been shown to have many negative health benefits.

Many studies have been done to compare HFCS and sugar, many of which show similar results. They’re practically the same thing – both very bad for us and should be avoided completely. It’s been linked to obesity, type 2 diabetes, and heart disease.

Avoid high fructose corn syrup


Avoid Sugar

Sugar, as most of us know, should be avoided at all costs. It is linked to obesity, type 2 diabetes, bad cholesterol, sugar addiction, and metabolic syndrome. It has no real nutrients and consumption typically leads to fat storage. It is labeled as many different things on nutrition packaging but a good rule of thumb is if it ends in “ose”, it’s sugar and should be avoided.

Regular table sugar is broken down into fructose and glucose when it enters the bloodstream. Glucose is naturally occurring in our bodies, but fructose is not. Excess fructose from over consumption gets turned into glycogen but can also be stored as fat once overloaded. This can cause fatty liver disease (among other things).

Avoid common sugar


Avoid Coconut Sugar

Coconut sugar is made from the flower of the coconut palm, where the sap is heated until the water is evaporated. The finished product is brownish in color. It retains some nutrients from the heating process and does contain some inulin, but is still not a good option for people on a low carb diet at 11g carbs per tablespoon.

It is made up of mostly sucrose (not to be confused with sucralose), which is half fructose and half glucose. Again, over-consumption of fructose leads to fatty liver disease and the storage of visceral fat surrounding the stomach. It has a GI of about 65, which is lower than expected mainly due to the insoluble fiber in it; but, it will definitely spike your blood sugar and insulin levels when consumed.

Avoid coconut sugar


Avoid Fruit Juice

Raspberries and blackberries are the 2 best types of berries to consume on a low carb diet due to the lower amount of sugars in them. While they can be consumed in moderation, it’s usually best to avoid fruit juices that are processed and used as a sweetener. Typically they contain fructose which has a very high glycemic index, resulting in both blood sugar and insulin spikes.

Most fruit juices will contain at least 20g carbs per serving, so they have no place in a low carb diet. If you want to learn more about fruits to eat and what to avoid, you can read a full keto food list here >

Avoid fruit juice


Avoid Honey

Honey is one of the most nutritionally dense sweeteners but is packed full of fructose and, like the other sweeteners to avoid in this list, lead to negative health effects. Most processed honey also has added sugars and is usually pasteurized, losing most of the nutritional benefits it has.

While honey is acceptable by some low carb dieters, it’s normally far too carbohydrate filled to be considered keto. One tablespoon of honey typically contains 17g carbs which is well over half of our daily allotted amount. There are many other ways to sweeten your foods with a much less glycemic index.

Avoid honey


Avoid Maple Syrup

While maple syrup and honey are widely accepted on lesser low-carb, paleo diets they are not allowed on ketogenic diets. Keto is a very carb-restricted diet so you have to be very strict with your consumption. Maple syrup typically has 13g carbs per tablespoon which means it’s half of the usual daily consumption of carbs for a small amount.

Maple syrup is a pretty nutritionally dense sweetener, it contains a high amount of magnesium, zinc, and calcium. It’s also rich in some vitamins and antioxidants but these can be found in many different forms of healthier food.

Avoid maple syrup

If you’re looking for a replacement for maple syrup on a ketogenic diet you can make your own or you can use a low sugar alternative like Walden Farm’s brand.


Avoid Agave Syrup

Typically a very highly processed sweetener even though it’s marketed as a natural alternative. It can contain up to 80% fructose which has a very high impact on our blood sugar levels and is typically seen as one of the most damaging sources of sugar. It is made by pressing the agave plant until the sugars and fluid come out and then processed under heat (destroying fructans, a healthy compound) similarly to high fructose corn syrup.

Agave syrup is generally seen as a low GI sweetener due to their marketing efforts, but don’t be fooled. While Agave Syrup is about a 9.6 GI due to low glucose content, it is mostly fructose and damaging to our liver.

Avoid Agave Syrup

Long-term use has also been linked with insulin resistance and chronically elevated blood sugar levels. It should be avoided, even in its natural state.