artificial sweeteners

Letting go of sugar is often the most challenging part of adopting a ketogenic diet. Sugar has been proven to have an addictive property, and stimulates the reward center in our brains when consumed, with effects similar to drugs! The good news is, after about two weeks your sugar cravings should subside and your taste buds will adapt to less sweet foods. In the meantime, or if you are craving a sweet treat, try an artificial sweetener. For people restricting carbohydrates, artificial sweeteners can mean the difference between raising your daily carbohydrate intake and satisfying that sweet craving.

The scientific research regarding artificial sweeteners is controversial. Many dieters opt to have a small amount of real sugar rather than add chemicals to their food. Additionally, some artificial sweeteners (I'm looking at you, Splenda) can destroy healthy gut bacteria and may even cause weight gain by altering metabolism. However, most of the negative effects of artificial sweeteners are seen when consumed in excess of 100x the recommended amount. The market for more "natural" artificial sweeteners has exploded due to consumer demand and awareness of chemical additives. In moderation, artificial sweeteners can be a useful tool in your ketogenic diet.

Artificial Sweeteners To Avoid


Sucralose is available both in liquid and powdered form. On average, the powdered form of this sweetener has a GI index of 80, meaning although it is low carbohydrate, it raises your blood sugar. Splenda is arguably the most controversial sweetener in the scientific community, although a consensus has not yet been drawn about its long term effects. However, some studies suggest sucralose can alter metabolism and hormone production. And while the glycemic index for the liquid version is not clear, it is known to be about 600 times sweeter than sugar. The jury is out on this artificial sweetener, so avoid it during your ketogenic diet.


Aspartame (Equal, NutraSweet) is probably the most common of all the artificial sweeteners. Aspartame has zero calories and no adverse effect on tooth enamel, but it has been found to be about 200 times sweeter than sugar. Few studies have also shown that the consumption of aspartame is related to dizziness, headaches, nausea, multiple sclerosis, systemic lupus, methanol toxicity, blindness, depression, weight gain and memory loss and a possible progenitor of cancer. However, aspartame remains on the GRAS (Generally recognized as safe) list from the FDA. Studies showing adverse effects of aspartame usually involve dosing 50-100x the recommended amount, so it is likely that 1-2 packets per week will not produce the same effects. Anecdotal evidence suggests aspartame has negative gastrointestinal side effects, notably bloating and diarrhea.

Recommended Artificial Sweeteners

While small amounts of real cane sugar are preferred, if you have strict macronutrient goals try pure Erythritol, Stevia, or Monkfruit. While these sweeteners are still a chemistry experiment (made by distillation), their origins are from plants. And beware of the different names used to hide sugar in the ingredient's list of the foods you buy.


Erythritol is a sugar alcohol (any compound with -ol means sugar alcohol) made by fermenting corn. The sugar alcohol is a product of fermentation. Erythritol has zero calories, does not raise blood sugar, and is not likely to cause gastrointestinal distress. Erythritol is not fully digested nor absorbed, which is how you get 60-80% sweetness of sugar without the calories.


Stevia is a sugar substitute made from the leaves of the Stevia rebaudiana plant. Stevia is 250-300 times sweeter than sugar, so a little goes a long way. Stevia has zero calories, and is generally blended with other sweeteners to tone down its inherent sweetness. At high concentrations, stevia may have a bitter taste. The research is rather young regarding the effects of stevia, some studies suggest it may actually lower blood sugar levels, implying stevia may have an effect on insulin action. For now, stevia is on the FDA's GRAS list.


Monkfruit sweetnener is made from concentrating juice from the Monkfruit plant, from China. Monkfruit is 150-200 times sweeter than sugar and has been used to sweeten foods in Southeast Asia for centuries. Monkfruit is on the FDA's GRAS list, with no conclusive negative side effects found. Blends of monkfruit, stevia, and erythritol are common.

The winner for the best keto sweetener: MONKFRUIT!

This brand especially, is the only artificial sweetener coming in at 0 carbs, whereas the rest contain a total of 4 net carbs.

Written by Caroline Wiswell, MS RD LDN


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