If you have a sweet tooth, the hardest part about eating a low-carb or ketogenic diet is avoiding sugar. So, when those sweet cravings call, what can you do without breaking ketosis? Fortunately, there are more and more keto friendly sweeteners you can reach for - including the newest natural sweetener called monk fruit.
What is monk fruit you ask? Let’s take a closer look to see if monk fruit is a good sugar substitute for a keto or low-carb diet.
What is Monk Fruit?
Monk fruit, also known as luo han guo or Buddha fruit, is not the most attractive looking fruit you’ll find in the produce isle. It’s a round gourd like fruit, characterized by a hard, brown skin that’s covered by hair, like a kiwi. The pulp and juice from inside the monk fruit is rarely eaten, but instead extracted to use as a concentrated sweetener. The juice from the monk fruit is extracted and then dried into a concentrated powder that’s approximately 300 times sweeter than sugar.
Like most fruit, it contains both fructose and glucose, but when luo han guo is processed, the sugars are separated from a compound called mogroside. Mogroside is responsible for what makes monk fruit extract so sweet.
The fruit originates from southeast Asia, where it was used for centuries as a low-calorie sweetener, and used in traditional Chinese medicine recipes, as a “cooling drink” for treating inflammation and fever[i].
Is Monk Fruit a Good Sugar Substitute for a Keto Diet?
To maintain ketosis, you must be vigilant to evict sugars from your diet. Since fructose and glucose are largely removed in monk fruit extract, it’s a good sugar substitute for a keto diet. The mogroside compound will satisfy your sweet tooth, without sacrificing your ketogenic state. Plus, monk fruit sweeteners have zero calories, so they won’t elevate your total calorie intake and cause weight gain.
Does Monk Fruit Affect Insulin Levels?
Monk fruit sweeteners can also be a good sugar substitute for those with diabetes or metabolic syndrome. Since there is no sugar, monk fruit extract won’t raise blood sugar.
In terms of insulin, there are conflicting reports on whether monk fruit extract induces an insulin response; however, in the study that showed an insulin response, it was actually a good thing.
In this study, the insulin response shown by ingestion of mogroside V, the most prevalent mogroside in monk fruit extract, allowed for the restoration of normal insulin secretion function in pancreatic β cells.[ii] This could actually be helpful to people with insulin resistance because it helps the body to properly respond to glucose in-take.
Beware of Monk Fruit Sweeteners with Added Sugars
Although sugars are removed from monk fruit during the extraction process, it’s very important to read food labels carefully when you buy a monk fruit based sweetener. Some food manufacturers will combine monk fruit extract with a small amount of sugar, or other sweeteners to dilute it. Keep in mind, some of these mixed sweeteners are not keto friendly if they contain any form of sugar in them.
One example is Monk in The Raw, which uses dextrose or maltodextrin, depending on the product, to dilute the sweetness. In very small amounts, like in one packet, the maltodextrin or dextrose probably won't hurt your ketosis. But beware of using anymore as the amount of maltodextrin/dextrose is not required to be on the label.
To make sure you’re selecting a keto friendly monk fruit sweetener, there are two areas you need to look on the food label. First, look at the nutrition information for listed sugars and carbohydrates. (Read this article if you need help reading nutrition labels). Then look at the list of ingredients. Again, you shouldn’t see any sugars listed here. Instead, you should only see monk fruit extract, or luo han guo listed on the ingredients. Sometimes manufacturers will also add inulin (aka chicory root fiber), or erythritol, a safe sugar alcohol, to dilute the overall sweetness.
We found a product without any added sweeteners called Pure Monk through Amazon. The Pure Monk is a little pricey, so if you don't mind using erythritol, then try out the Lakanto Monkfruit product for a cheaper natural sweetener. There is also MonkSweet Plus which is a mixture of stevia, monk fruit and erythritol - which may make for a nice natural flavor. And last but not least, if you enjoy keto almond flour pancakes every now and then, try out Lakanto Monk Fruit Maple Syrup.
How is Monk Fruit Used?
Like stevia, monk fruit extract can be used as a sugar substitute for a variety of dishes, including beverages, sauces, and sugar-free sweets. It’s also heat stable, so it can even be used for keto coffee, or keto friendly baking too. Some people have allergic reactions to stevia, so monk fruit is a great substitute for stevia for those people.
If you’re using monk fruit as a sugar substitute in one of your favorite recipes, remember that monk fruit extract is about 300 times sweeter than sugar in pure form. So, before you start pouring it in, make sure you read the directions on the packaging. Most manufacturers include a recommended substitution ratio. If you ignore it, you could end up with some unbearably sweet keto treats.
In addition, if you buy packaged low-carb treats at the store, you may start to see monk fruit extract or luo han guo listed in the ingredients. Now that you know what it is, there's no need to be afraid of it in these products. But like we said earlier, you should be aware of the other additives like artificial sweeteners that could be in the low-carb food product too.
The Added Benefits of Monk Fruit
Monk fruit has been used in traditional Chinese medicine for centuries to treat common ailments, such as sore throat and fever. There are no clear studies to back up this medicinal usage, but there are some limited studies suggesting some potential benefits related to inflammation, cancer and diabetes.
Mogroside, the chemical component which makes monk fruit sweet, has also been found to have antioxidant properties[iii],[iv]. Given these antioxidant properties, monk fruit could help prevent oxidative stress which is believed to influence inflammation and chronic diseases such as type 2 diabetes, and heart disease.
For those with diabetes, monk fruit may also have some benefits aside from being an alternative to sugar. In studies, when mice were given monk fruit extract, they were shown to have a reduced blood sugar levels[vii],[viii].
With all of this said, it’s important to recognize that all of these potential benefits have been identified in mice, and many of these studies use very large concentrations of monk fruit. So, without more research, it’s unclear how much monk fruit extract you’d have to consume to gain these additional health benefits.
However, if you’re looking for a keto friendly sweetener that won't break your ketosis, monk fruit is an excellent option, especially compared to artificial sweeteners like aspartame or sucralose which often carry negative risks of their own. Just make sure to read the label to ensure your monk fruit sweetener doesn’t include any added sugars, and you’ll be good to go.
[i] Dharmananda S. Luo han guo: Sweet fruit used as sugar substitute and medicinal herb. Institute for Traditional Medicine Online. 2004
[ii] Q. Xu, S.Y. Chen, L.D. Deng, L.P. Feng, L.Z. Huang, and R.R. Yu. Antioxidant effect of mogrosides against oxidative stress induced by palmitic acid in mouse insulinoma NIT-1 cells. Braz J Med Biol Res. 2013 Nov; 46(11): 949–955.
[iii] Chen WJ, Wang J, Qi XY, Xie BJ. The antioxidant activities of natural sweeteners, mogrosides, from fruits of Siraitia grosvenori. Int J Food Sci Nutr. 2007 Nov;58(7):548-56.
[iv] Q. Xu, S.Y. Chen, L.D. Deng, L.P. Feng, L.Z. Huang, and R.R. Yu. Antioxidant effect of mogrosides against oxidative stress induced by palmitic acid in mouse insulinoma NIT-1 cells. Braz J Med Biol Res. 2013 Nov; 46(11): 949–955.
[v] Can Liu, Yan Zeng, Long-Hai Dai, Tian-Yu Cai, Yue-Ming Zhu, De-Quan Dou, Lan-Qing Ma, and Yuan-Xia Sun. Mogrol represents a novel leukemia therapeutic, via ERK and STAT3 inhibition. Am J Cancer Res. 2015; 5(4): 1308–1318.
[vi] Takasaki M1, Konoshima T, Murata Y, Sugiura M, Nishino H, Tokuda H, Matsumoto K, Kasai R, Yamasaki K. Anticarcinogenic activity of natural sweeteners, cucurbitane glycosides, from Momordica grosvenori. Cancer Lett. 2003 Jul 30;198(1):37-42.
[vii] Xiangyang Q, Weijun C, Liegang L, Ping Y, Bijun X. Effect of a Siraitia grosvenori extract containing mogrosides on the cellular immune system of type 1 diabetes mellitus mice. Mol Nutr Food Res. 2006 Aug;50(8):732-8.
[viii] Qi XY, Chen WJ, Zhang LQ, Xie BJ. Mogrosides extract from Siraitia grosvenori scavenges free radicals in vitro and lowers oxidative stress, serum glucose, and lipid levels in alloxan-induced diabetic mice. Nutr Res. 2008 Apr;28(4):278-84. doi: 10.1016/j.nutres.2008.02.008.