The keto diet – or any low-carb diet like paleo or Atkins – requires a lot of sacrifices.

Most people focus on the “obvious” ones: no bread, no pasta, no rice, no potatoes, no sweet desserts, and of course, no fast food. No milk, soft drinks or energy drinks, either. And even most fruits are on the “foods to avoid” list.

Following keto guidelines gets even more difficult, though, when you realize that most of the packaged and processed foods that make up a large part of the typical American diet are also off-limits.

You’re planning to substitute cauliflower pasta for regular noodles? Great, but the pasta sauce in your pantry is probably a no-go. You’re going heavy on meat because keto encourages it? Sorry, but forget about the honey-baked ham you love to eat for lunch. The healthy fruit juice you’ll be drinking in order to avoid soda? That’s on the “naughty” list, too.

There’s usually one culprit to blame: sugar. You probably know that sugar is one of the worst things you can add to your food when on the ketogenic diet, but most people don’t realize how much added sugar they consume on a daily basis. It’s one of the major causes of the obesity so prevalent in America today.

There are now many keto-friendly alternatives to packaged and processed foods; many supermarkets even have shelves full of them.

But what do you do when you want to add sugar to your coffee, or to a recipe you’re whipping up in the kitchen?

You consult our list of the three best keto sweeteners – and use one of them to replace the sugar that may completely bust your diet. (And if you’ve never heard of monk fruit extract, prepare to be amazed.)

We’ll get to the list after a brief refresher on the keto diet and the reasons why so many foods must be avoided.

You don’t have to be a nutritionist or medical professional to know that consuming lots of sugar isn’t great for your health. Keto guidelines are a lot stricter though: virtually no added sugar at all.

This seemingly-draconian rule makes sense, though, once you know how keto meal plans help you lose weight so quickly and effectively. We’ll go through it in bite-sized pieces.

1. The body and brain need energy to function. Normally, the body’s fuel is created when dietary carbohydrates – the carbs we eat every day – are burned and turned into glucose (blood sugar).
   
2. If we don’t consume enough carbs to make energy, the body needs to get energy in some other way. Here’s what it does: it enters a metabolic state called ketosis. That allows the liver to produce molecules called ketones by burning stored body fat. And fat-burning causes weight loss.
   
3. The body functions just fine on ketones, but it’s built to run on glucose. So as soon as it gets enough carbs to make more glucose, it is “kicked out” of ketosis. Ketone production, and weight loss, stop.
   
4. That’s the beauty of the keto diet. It’s designed to deprive the body of carbohydrates, forcing it to run on ketones – and producing the weight loss that’s a direct result.

There’s one important fact to consider: what we call “sugar” is actually sucrose. And sucrose is just shorthand for “soluble, sweet carbohydrates.” In other words, every teaspoon of sugar is nothing more than a delicious teaspoon of carbs.

How much damage can a teaspoon do? Well, on a strict keto diet you can only consume 20-25 net carbs per day. (Net carbs = total carbs - dietary fiber, since fiber isn’t digested.) That teaspoon of sugar contains about four carbs.

When you do the math, you find that two cups of coffee, each with two teaspoons of sugar, total 16 carbs – or almost a complete day’s allowance, just in your morning coffee and another one after you get to work. And that’s not even considering the carbs that are in all of the food you’ll be eating for breakfast, lunch and dinner.

Bottom line: sugar isn’t great for you. A normal day’s worth of sugar can be even more problematic if you’re trying to lose weight.

And if you’re on a keto diet, sugar can kick you right out of ketosis and destroy your diet before you even realize it.

(Debunking a common myth: so-called natural sugars like brown sugar and turbinado sugar aren’t any better for you than granulated sugar. And corn syrup is even worse; it contains dextrose, which is chemically identical to glucose.) 

Obviously, all sorts of sugar substitutes have been on the market for generations. Manufacturers use these sweeteners in “sugar-free” or “diet” products, and they’re right there on the counter or table if you order coffee in a restaurant.

Many of them are low-calorie. Some even contain zero calories. But that doesn’t necessarily mean that they’re low-carb or zero-carb. And even if they are, they may still be bad choices for keto dieters.

Our first order of business will be to reveal the very best keto sweeteners. After that, we’ll dig a little deeper and explain why some common sugar alternatives should be avoided by those on a keto diet.

1. Monk Fruit Extract

This natural sweetener has been getting more attention lately, but those who don’t pay attention to nutritional or diet trends may still not be aware of it.

Monk fruit sweetener is sourced from the fruit of – you guessed it – the monk fruit tree (Siraitia grosvenorii). It’s a small fruit that looks like a gourd and is native to South Asia (particularly Southern China) where it’s known as luo han guo. And it has been used for medicinal purposes for centuries; it’s most often turned into tea because the fruit goes bad soon after it’s picked.

What’s most interesting for our purposes is that monk fruit is also incredibly sweet – 150-200 times sweeter than table sugar. That unusual sweetness is due to the presence of compounds called mogrosides, which also provide impressive health benefits. We’ll get to those shortly.

The extracts from many types of fruit are quite sweet. What makes monk fruit extract so unusual, however, is that it contains only mogrosides; all forms of sugar, like glucose and fructose, are removed during the extraction process. That allows the sweetener to pass through the gastrointestinal tract without being digested.

And no digestion means no calories or carbs are absorbed or processed by the body.

That’s one reason that monk fruit extract is the ideal sugar replacement. The others are the health and wellness benefits we’ve mentioned:

• Preliminary testing shows that mogrosides lower blood glucose levels and encourages the body to produce insulin. Controlling blood sugar levels is very important for diabetics, of course, but it can also work to prevent the insulin resistance that may lead to the development of type 2 diabetes. (Incidentally, monk fruit extract’s glycemic index is zero, ideal for diabetics.)
• Mogrosides contain bountiful levels of antioxidants, and also work as anti-inflammatories. That means they can help prevent the oxidative stress which leads to a laundry list of health issues including asthma, heart disease, inflammatory diseases and cancer.
• Monk fruit extract has been shown to improve cholesterol levels, increasing “good” cholesterol and decreasing “bad” cholesterol.
• A zero-calorie, zero-carb sweetener like monk fruit can obviously be an attractive sugar substitute for keto dieters. But there’s also some evidence linking monk fruit extract and similar products to weight loss when used in conjunction with diet plans and exercise.

The U.S. Food and Drug Administration (FDA) approved the use of monk fruit sweetener more than ten years ago, describing it with their usual phrase: Generally Recognized as Safe. In fact, there are no known side effects associated with this keto-friendly sweetener. Monk fruit extract is considered a stable compound, so you can cook or bake with it, too. The only drawbacks are that it has a slightly bitter aftertaste and it’s more expensive than other alternatives.

We do have one caution, though. Since monk fruit extract has such a super-sweet taste, only a tiny bit is needed to provide the sweetening effect of an entire teaspoon of sugar. That presents a logistical problem: how the heck do you add it to your coffee? Even more baffling: how do you put the right amount into one of those convenient restaurant packets?

Manufacturers have come up with an easy solution – but it ends up blunting or eliminating many of the benefits of monk fruit extract. They add something else to the monk fruit before selling it, which takes care of the “bulk issue.” That way, it’s easy to put a “teaspoon” of monk fruit sweetener into your beverage or fill up a teaspoon-sized packet.

Sometimes they add a similar sweetener, stevia, along with the sugar alcohol erythritol (more about both shortly). They may add allulose, a natural sweetener that’s chemically similar to table sugar. Sometimes they add the sweet food additive maltodextrin, which is bad for diabetics because of its high glycemic index. And some even add molasses or even regular sugar! Both are definitely not keto-friendly, and completely defeat the purpose of using a zero-carb sweetener.

There’s one way to protect yourself and reap the benefits you’re expecting from monk fruit: use only pure monk fruit extract, which is sold in bulk containers. It’s more difficult to measure out the right amount, of course, but it’s worth it. Brands like Purisure and Pure Monk Sweet are each 100% monk fruit extract, while Monk Fruit in the Raw contains erythritol – and Nectress contains molasses and sugar, even though it’s advertised as “monk fruit sweetener.”

Choose monk fruit extract – and you’ll be using the best keto sweetener available. One note: the best keto-friendly ready-to-drink products, like Super Coffee, rely on monk fruit extract as their sweetener of choice.

2. Stevia

Several natural sugar substitutes are known as “novel sweeteners,” since they’re relatively new to the market and they work in different ways than traditional alternatives. Monk fruit extract is one. Stevia is the other well-known one. 

Stevia is derived from the stevia plant, which unlike monk fruit, is native to South America. In many other ways, though, the two novel sweeteners are quite similar. Stevia has also been used for medicinal purposes for centuries, and its ability to act as a sweetener was discovered much more recently. It’s produced via extraction, like monk fruit extract, with its active ingredients, stevioside and rebaudiosides, isolated for use as natural sugar substitutes.

The similarities don’t end there. Stevia also passes through the digestive system untouched, so it is carb-free and calorie-free with a glycemic index of zero. It lowers blood sugar and insulin levels, just like monk fruit, and also improves cholesterol levels while acting as a powerful antioxidant. Oh, and it’s also fine for cooking and baking.

One more thing: it’s also so sweet that just a tiny amount is needed to provide the sweetness of sugar. Stevia products are often “bulked up” the same way that monk fruit products are; NuNaturals and Now Foods sell pure stevia extract, while options like Truvia and Stevia in the Raw contain other sweeteners that dilute stevia’s beneficial properties. Be careful of liquid stevia as well; it’s often produced with an alcohol base.

They sound like they’re basically the same, so why is monk fruit extract a better choice? There are two reasons. First, stevia’s aftertaste is more pronounced than monk fruit’s. Second, monk fruit appears to provide a greater variety of health benefits.

They’re both terrific keto sweeteners, though.

3. Erythritol

This natural sweetener a sugar alcohol. Those substances are naturally found in some fruits and vegetables; for example, erythritol occurs naturally in pears, grapes and mushrooms, as well as fermented foods like cheese and beer. These days, however, it’s often produced commercially from fermented corn sugar.

Paradoxically, erythritol (like all sugar alcohols) is a carbohydrate – in fact, it contains as many carbs as sugar – but because it’s fully absorbed in the small intestine and isn’t metabolized before it’s flushed from the body, it doesn’t boost blood sugar levels. In fact, there’s some evidence that it actually lowers them. For those reasons, erythritol is considered to contribute zero carbs on keto and other low-carb diets. It’s calorie-free, too.

Erythritol isn’t quite as sweet as sugar, putting it in very different territory than novel sweeteners. For one thing, there’s very little need to “bulk it up” with other types of sweeteners. It can stand on its own.

There’s another huge difference, though. Novel sweeteners are ideal for everyday use, but erythritol isn’t. It’s somewhat gritty and doesn’t dissolve well in liquids so it’s primarily used in cooking and baking, In fact, erythrol is the most common of the low-carb sweeteners found in commercially-produced foods. One exception: the sweetener Swerve, which is made with erythritol, oligosaccharides (the pre-biotic fiber inulin, sourced from chicory root) and flavorings.

There’s another noteworthy fact about erythritol; it’s by far the best sugar alcohol to use in keto cooking and baking. Others, like sorbitol, mannitol, maltitol and xylitol, are known to cause digestive issues like bloating and diarrhea. Erythritol doesn’t cause the same side effects for most people, although it can cause some distress for those with gastrointestinal illness. (Sorbitol and maltitol also contribute carbs to a keto diet and should definitely be avoided).

In short: erythritol is the best keto sweetener to use in keto recipes. Monk fruit extract and stevia are the best keto-friendly sweeteners for everyday consumption.