I’ve written quite a lot on why we need to control blood sugar and our insulin response on this blog, and naturally that usually means controlling sugar in the diet. This fact often spurs a question in my readers about non-nutritive sweeteners. Which are good, which are not?
Like most of the subjects we discuss, the answer is: it depends!
First let’s get a good understanding of the types of sweeteners that are out there. There are many ways to classify sweeteners. They can be classified based on nutritive status, whether or not they are natural or synthetic and according to their sweetness.
Nutritive Sweeteners: Nutritive, means that the sweetener provides calories or energy.
The most obvious here is sucrose (table sugar). This tends to be the standard to which most other sweeteners are held to in taste and sweetness. Sugars can be identified by their ending -ose. So, if you see a chemical name on a food label that ends in -ose, (i.e. dextrose), then you are dealing with a form of sugar. Other sugars include, honey, agave, corn syrup, high fructose corn syrup, rice syrup, molasses, maple syrup and many more.
Sugar alcohols are sweeteners that can be 25-100% as sweet as table sugar and can be identified by their ending of -ol. They are often thought of as non-nutritive sweeteners, but actually some of them are not calorie free. Examples are xylitol, sorbitol and maltitol. The one exception to this is erythritol, which only has 0.24 calories per gram, making it 95% less caloric than table sugar, so unlike most sugar alcohols, it is considered a non-nutritive sweetener.
Non-Nutritive Sweeteners: Non-Nutritive, means the sweetener provides no to very minimal calorie (energy). Most non-nutritive sweeteners are much sweeter than table sugar. They can be a hundred to thousands of times as sweet per gram. These are referred to as high intensity sweeteners. There are 8 FDA approved high intensity sweeteners. These are: Acesulfame potassium (Ace-K or Sunett), Advantame, Aspartame (Equal, Nutri-Sweet), Luo han guo fruit extracts (Monk fruit extract), Neotame, Saccharin (Sweet’n Low), Steviol glycosides (Stevia), and Sucralose (Splenda). There are two non-nutritive sweeteners that are not high-intensity. These are erythritol, as discussed above and allulose.
Now that we have looked at the sweeteners based on their caloric value, let’s take a look at them based on if they are natural or not.
Natural sweeteners are derived from nature. This includes Stevia, Monk Fruit and sugar alcohols. Sugar alcohols can be found in nature or produced industrially. They have a chemical structure similar to sugar and to alcohol, but they actually are neither.
Allulose: Allulose is newer to the market, just gaining FDA approval as a low-calorie sweetener in 2015. It exists naturally in wheat, raisins and figs and so is referred to as a "rare sugar." It is an actual sugar, but our bodies are not able to metabolize it and nearly all of it passes in the urine without being absorbed. Some studies in animals suggest there may be even more benefits to taking allulose, including better blood sugar control. More research is needed, but it is encouraging. Allulose doesn’t seem to cause any digestive side effects making it a good choice for those with a sensitive gut. It also doesn’t have an after-taste and bakes and freezes like sugar. It is about 70% as sweet as table sugar.
Stevia: Stevia will not raise blood sugar or cause an insulin rise, in fact there is some evidence that it can improve blood sugar and insulin levels. It is not absorbed in the GI tract. It arrives undigested to the colon and is then broken down by the gut bacteria, but it does not stimulate the gut. Stevia can have a bitter after-taste that might take some getting used to for some. Stevia is about 200-350 times as sweet as sugar.
Monk Fruit: Monk Fruit seems to have a very small but present stimulating effect on insulin. This is very minimal, and for most individuals, they won’t notice an issue or a glucose rise, but perhaps if quantities were large, it could be seen. This is despite it having no calories, and no carbohydrate value. Monk Fruit is also very minimally absorbed by the GI tract making it well tolerated. It also does not have the same bitter after-taste that we see with stevia. Monk Fruit is about 150-200 times as sweet as table sugar.
Erythritol: As stated above, erythritol only provides 0.24 calories per gram so it has very minimal calories. It occurs naturally in small quantities in fruits and fungi. It is made commercially by fermenting corn. It does not seem to raise blood sugar or insulin levels. It does however, have a stimulatory effect on the gut with approximately 90% of it being absorbed. What is interesting is although absorbed, it is not metabolized much at all. Erythritol is about 70% as sweet as sugar.
Xylitol: Xylitol has a small but present insulin response that can reach in some individuals 16-25% that of table sugar. It also has calories (about 2.4 per gram). This could be enough to inhibit ketosis for those on a ketogenic diet, so if this is your goal, you need to keep it in mind if using larger quantities for baking. The small amounts in sugar-free gum or the like are not likely to cause an issue. It does stimulate the GI tract and is absorbed but is not fully metabolized. Something to remember is if you have a dog, you have to keep this away from them. It is highly toxic to dogs, so perhaps not the best choice for families with fur-babies. Another interesting thing about xylitol is it can help prevent tooth decay. Xylitol is equal in sweetness to table sugar.
Because sugar alcohols are stimulating to the gut, they can in some individuals cause some GI upset. Maltitol is probably the worst when it comes to this (hello, bubble-guts!) and erythritol tends to be the best tolerated, but tolerance is very individual and dose dependent. Maltitol is popular in commercial products as it behaves a lot like sugar, especially in candy making, but it does raise blood sugar and insulin about ¾ as much as sugar, so not the best sweetener for low carb diets. It is about 80% as sweet as sugar.
Artificial Sweeteners are synthetically produced food additives that do not exist in nature.
Sucralose (Splenda): Sucralose is made from table sugar but it has a different chemical structure so the body cannot recognize it or metabolize it for energy and is therefore calorie free. It doesn’t seem to cause a blood sugar or insulin response; however regular use has been associated with negative alternations in the gut microbiome (bacteria in the colon) that can make a person more insulin resistant. This seems like an unfortunate thing for something that people that already have blood sugar problems would consume thinking they are helping themselves. Sucralose is about 600 times as sweet as sugar.
Aspartame (Equal): Aspartame doesn’t seem to cause a significant blood sugar or insulin response, but it is digested and metabolized. It is important to know that it is made from amino acids which makes it stimulatory to growth pathways. This is important if someone is intermittent fasting as it’s use would technically break their fast. It also can stimulate the gut and has been associated with microbiome changes as well as has been associated with many ill effects such as headaches and the like. That being said, I don’t think there is a more studied food additive than aspartame. Aspartame is about 200 times as sweet as table sugar.
Acesulfame K (Ace-K, Sunett and Sweet One): this is the most common sweetener in sugar-free sweetened drinks. It has no calories or carbs but studies are mixed on if it can raise blood sugar and insulin levels. It is about 200 times as sweet as table sugar.
Saccharin (Sweet’n Low): Some research suggests that saccharin may have negative effects on metabolic health and gut health in some people. It also, at large doses, was associated with bladder cancer in rodents, although this is not known to have happened in humans. It can have a bitter after-taste. Saccharin is about 300 times as sweet as table sugar.
Using sweeteners on a low carbohydrate diet can be a double-edged sword and I think it is up to the user to know themselves and know if it is a good decision for them. For some people, it might stimulate cravings and lead to over-eating. There is evidence that sweetened drinks particularly are associated with weight gain, even if diet.
For some people, having some sweet treats made with non-nutritive sweetener is a nice tool to help them enjoy an occasional treat and stick to their nutrition plan. This can make a low carbohydrate lifestyle easier to maintain long term for some.
For those with sugar addictions, there is evidence that just replacing sugar for non-nutritive sweetener can maintain the addiction as the same neural pathways are stimulated when we taste sweet even if they are calorie free.
Personally, I do bake for my family some low-carb treats, usually on the weekend. Other than these once (or twice) a week treats, we don’t have many sweets in our home. Eating low carbohydrate helps you to appreciate the subtle sweetness in whole foods and often leads to less of a need for sweet treats. But it is nice to still be able to make cookies with my daughter on a Saturday, or make special treats for celebrations such as birthdays. My husband has a major sweet-tooth and these treats help him to stay on his nutrition plan without feeling deprived. It is important to know yourself in this regard, track your progress so you can make the best decision for yourself.
Do you like a sweet treat every once in a while? What are your favorites? Comment below!