Keto Diet Sweeteners


All sweeteners are not created equal.  There are natural sweeteners, sugar alcohols (polyols), and synthetic (artificial) sweeteners, and they all have different values on the GI (glycemic index).  There are some you should even avoid.  Some can cause insulin spikes, while others can cause mild to severe digestive upset.

While some say that sweeteners do not help curb sweet cravings, most people just find it too hard to give up, especially in the beginning.  As you get further along in your Keto lifestyle, you will have less and less of a taste for sweet things.  But if you want to use sweeteners, you should understand the good, the bad and the ugly.

If you are on a very low carb (under 20g/day) diet, there are only a couple sweeteners that are truly “zero carb” and they should always be used in their purest form. 

Beware of ‘blends’ that use the bulking agents Dextrose and/or Maltodextrin, which are actually made from starches and puts them higher on the glycemic index.

The safest sweeteners on a strict low-carb diet are Stevia and Erythritol, which both have a GI of zero.

Although Erythritol is listed as a sugar alcohol, it’s different because it does not spike blood sugar or insulin.  We do not have the enzymes in our bodies to break down.  It’s absorbed into the bloodstream and is then excreted unchanged in the urine.  As such, Erythritol does not cause digestive issues like some of the others.  After many toxicology and clinical studies, Erythritol has been found to be completely safe for consumption as a sugar substitute.  The benefits of Erythritol include;

  • Fermented – it is made by fermenting the natural sugar found in corn.
  • Heat stable up to 160 degrees C. (320 degrees F)
  • Non-caloric – While most sugar alcohols are low calorie, Erythritol has zero calories.
  • Non-glycemic – Does not raise blood sugar – Erythritol is considered suitable for people with diabetes because it does not raise plasma glucose or insulin levels.
  • The easiest sugar alcohol to digest – more than 90% of Erythritol is absorbed in the small intestine, so minimal amounts reach the colon where other sugar alcohols end up causing diarrhea and other symptoms. Studies have shown that Erythritol is even easier to digest than Xylitol.
  • Noncarcinogenic– studies have shown that Erythritol, like Xylitol, does not have carcinogenic properties.
  • An antioxidant – Erythritol helps to fight free radicals, responsible for the aging process. It is considered to be even more efficient than other sugar alcohols because it is so readily absorbed and yet not metabolized (it is excreted unchanged).

Swerve brand is my go-to for most everything!  It comes in granular, confectioners (powdered) and packets.

Stevia is a naturally-occurring, zero calorie sweetener with a number of health benefits that have been confirmed in human studies.  In all recent studies, Stevia has not been shown to cause any negative health effects.  Like Erythritol, Stevia does not spike blood sugar or insulin, and is not known to cause digestive issues.  Steviol glycosides are poorly absorbed in the body and pass through the upper gastrointestinal tract fully intact. Once steviol glycosides reach the colon, gut bacteria convert steviol glycosides into steviol.  Steviol is then metabolized by the liver before being excreted in the urine.

Research has shown that there is no accumulation of stevia (or any byproduct of stevia) in the body during metabolism. It is because of this poor absorption in the digestive tract that stevia has zero calories and does not raise blood glucose or insulin levels when digested.  Studies clearly support the safety of stevia sweeteners. Further, clinical studies showed that steviol glycosides have no effect on either blood pressure or blood glucose response, indicating stevia sweeteners are safe for use by individuals with diabetes.

I think Monk Fruit should get an honorable mention here as it’s very underrated.  It has a zero glycemic index, contains no calories and is suitable for diabetics.  About 300 times sweeter than sugar, liquid and powdered lohan guo concentrate is derived from the antioxidant-rich, lemon-sized fruits of trees that thrive in the hot, misty mountains of southern China and northern Thailand and were allegedly first cultivated by Buddhist monks 800 years ago.

Sugar Alcohols all have a place in the GI and will affect blood sugar to some degree, with the exception of Erythritol.  As such, they should be used with caution.  Xylitol, Maltitol, Sorbitol are commonly used in many “sugar free” products.  Some people can consume these products with little to no effect on their insulin or digestive system.  For others, however, they can significantly spike insulin levels and cause an undesirable laxative effect.  You will have to gauge for yourself how these affect you.  For anyone starting out on a <20g carbohydrate diet, I would caution they be avoided.

Caution: Anyone with dogs should note 

Synthetic Sweeteners, such as Aspartame, Neotame, Saccharin and Sucraolose are all artificial sweeteners that have some degree of controversy.  

Splenda (Sucraolose) gets a bit of a bad rap.  It has been around since 1976 and is probably the most thoroughly researched synthetic sweetener out there.  Sucralose on it’s own is not horrible, but the problem is “Splenda” is made with Maltodextrin, the bulking agent mentioned above, and thus gives it a value on the GI.

There was an uproar following a lone Italian study which claimed it caused leukemia in mice, and a review published in the Journal of Toxicology and Environmental Health suggested that sucralose can alter the balance of bacteria in the gut, possibly leading to weight gain.  Although these studies might raise an eyebrow, you should remember that they were all done on mice or rats and used VERY large quantities of chemicals. Secondly, the Italian study didn’t even use sucralose, but a hydrolyzed chlorocarbon related to sucralose.  Sucralose has been approved by the FDA, the European Union’s Scientific Committee on Food, the Health Protection Branch of Health and Welfare Canada, and Food Standards Australia New Zealand, among others

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