Medically reviewed by, Russell Braun RPH
At this point the evidence supporting fasting is clear. However, in the middle of a fast everyone gets hungry. If you can relate, then you want to know what will decrease that hunger. All the while keeping the benefits of that fast. Water and black coffee are on your “all good” list. However, what about a little sweet taste? Do artificial sweeteners like stevia really break a fast?
1. What Does Break A Fast Mean Exactly?
Typically, fasting simply refers to are you consuming calories or not. Zero calories is technically a requirement to keep you fasting. However, there three are other components to keep in mind. These include the impact on the autophagy, digestive hormone level and the digestive process.
This is similar to the idea of comparing 200 calories from cheetos to 200 calories from broccoli. Clearly these do not impact your body the same way, even though it is the same number of calories. Artificial sweeteners have a similar complexity when interacting in your body. Therefore, you need to take some important factors into account.
Autophagy is the most important benefit of fasting. It is a breakdown and repair processes cells undergo during fasting. Research into autophagy won the nobel prize and has been proven to help prevent aging and increase longevity. Basically when your cells think your starving during a fast. This causes them to breakdown parts that are not functioning well to prepare you for going without food. A process known as mTOR regulates this balance between cell buildup or breakdown.
A major nutrient in our diets that stops mTOR in its tracks is protein. Subsequently, protein is made from amino acids which also stop mTOR. The bad news is that several artificial sweeteners contain amino acids. Use them and poof… there goes the benefits of autophagy!
“Important question #1…. do artificial sweeteners like stevia contain protein or amino acids?”
The thing many dieters don’t realize is that hormones control your ability to lose weight. Specifically insulin, which is released by the pancreas, in response to ingesting food and beverages. Insulin is the glucose uptake and fat storage hormone. It is released in response to a higher degree in response to carbohydrates like sugar and to a certain extent to sweet tastes.
To get the benefits of fasting, you want insulin to be low and stay low. In response the sister hormone glucagon will be released. This hormone actually raises blood sugars back up by getting stored energy to be released. That is what you want and another huge benefit of fasting. Once the sugar energy stores called glycogen are gone, you start burning fat as a fuel source.
Important question #2…. do artificial sweeteners like stevia cause insulin levels to rise?
Stimulating your digestive system is also another no-no during fasting. Most people do not realize that digestion consumes a large amount of energy in the form of calories and diverts blood flow away from other areas and into your intestines.
Digestion also results in increased work for the immune system. Over 70% of our immune system is found in and around the gut. As things we eat get absorbed, our immune system is making sure to get rid of invading bacteria, viruses and food particals that should not get in. Ensuring this process has a chance to slow down for a while is a key benefit of fasting.
Important question #3…. do artificial sweeteners like stevia start the digestive process?
2. What Is Stevia Anyway?
Stevia is part of the sunflower family and is native to South America. It resembles mint and is very sweet. In fact, it is estimated to be between 200-400 times sweeter than regular sugar. Stevia is a non nutritive sweetener, which means it does not contain energy measured in the form of calories. Other sweeteners such as sugar are nutritive, meaning they do contain calories.
Glycosides provide the sweetness and are a natural part of the Bertoni plant that stevia comes from. Examples of these glycosides which you may see on stevia labels include:
- Rebaudioside A
- Rebaudioside C
Stevia Compared To Nutritive Sweeteners
Natural stevia, which contains glycosides is a great sweetener option. It is quickly becoming one of the top sugar substitutes because it is a natural plant based product. The reason being is that the potent sweetening effect from a small amount of the product.
Stevia does not provide calories like regular sweeteners do. The table below compares stevia to other sugar sweeteners used in many processed foods today.
|Sweetener||Calories Per Tablespoon (20 grams)|
|High fructose corn syrup||57|
Stevia Vs. Other Non-Nutritive Sweeteners
Stevia is not the only sugar substitute that contains zero calories (which makes them all non-nutritive sweeteners). Most of these are synthetic, or man made in a lab. They are also much sweeter than natural sugar.
There are currently eight artificial sweeteners approved by the Food and Drug Administration (FDA).
|Non Nutritive Sweetener||Number of Times Sweeter Than Sugar|
|Monk Fruit||100-250 x|
As you can see some of the synthetic sweeteners are very, very sweet. In fact, these artificial sweeteners have been labeled as high intensity sweeteners by the FDA. You can read more here about their approved usage in the United States.
It is important to note these sweeteners trick your brain into thinking some sweet food is about to be in your belly. That said, some have been found to stimulate insulin release and start the digestive process. Another problem is that artificial sweeteners overall may cause you to be addicted to sweet taste. This has been suspected to cause more calories to be consumed overall. This is important to remember and as with anything moderation is key.
3. Can I have Artificial Sweeteners While Intermittent Fasting?
Based on the table above it is clear that Stevia contains zero calories. Based solely on calories the answer would be “no” it does not break that fast. However, does that mean it won’t break your fast?
However, keep in mind we need to ask the three questions laid out above before grabbing the stevia off the shelf. These will be the key things to get the benefits you want from fasting.
- Does it stop autophagy?
- Will it impact your digestive hormones?
- Does it start the digestion process?
Autophagy is the process that starts cellular repair and it one of the primary benefits of fasting. A pathway called MTOR is the primary means that triggers autophagy in cells. Any protein or amino acids will stop MTOR.
Pure, natural stevia does not contain protein or amino acids. That means it will not stop autophagy. However, keep in mind the foods stevia is used to sweeten may stop this process or affect hormones or digestion. Typically, putting some stevia in lemon water or coffee would not stop autophagy.
Does Stevia Spike Insulin?
Insulin is release by the pancreas in response to foods. This process is triggered even before the food reaches the stomach. That means that taste and chewing can start insulin release.
Some non caloric artificial sweeteners are so sweet (remember the FDA calls them high intensity sweeteners) that they can trick your system into releasing insulin. This could lead to insulin resistance and prevent some of the weight loss benefits of fasting. Another drawback of super sweet artificial sweeteners is making you crave sweetened foods. This may increase appetite and overall calories you eat.
Many studies show conflicting data on artificial sweeteners and the insulin response. However, stevia has actually been shown to have a beneficial affect on insulin resistance. It also does not appear to stimulate insulin release and may have a positive impact on blood glucose.
3. Digestive Process
After stevia is swallowed in the food or drinks it sweetens it moves down your GI tract. The good news is, It is not even absorbed into your bloodstream. Instead it travels all the way to your colon, where bacteria break it down.
Stevia has actually been shown to be a prebiotic for certain strains of bacteria in the colon. Prebiotics serve as food for healthy gut bacteria. Another potential bonus is that stevia root contains inulin. This compound is a preboitic for multiple beneficial bacteria in the colon. Look for stevia brands that contain inulin where possible.
The key takeaway is that stevia will not stimulate digestion. This will ensure adequate resting of the GI tract during your fast.
4. Does Stevia Break Ketosis?
Ketosis is the state of metabolism that people following the ketogenic diet strive for. Basically it means they are burning fat for fuel instead of carbohydrates. When the body gets into a state of ketosis it burns fat only and this helps with weight loss.
Ketosis is dependent on having low blood glucose and insulin levels. The body then uses fat as a fuel when glucose reserves called glycogen are depleted. Stevia checks both of these boxes because it does not have calories thus no blood glucose increase. As discussed it also does not increase insulin levels.
Therefore, people who wish to stay in ketosis can use stevia. The ketogenic diet restricts carbohydrates to reach ketosis. That typically means people on this diet can’t eat anything sweet. Thus stevia is a good sweetening option for them.
5. Does Lemon Water With Stevia Break A Fast?
Water is one of the best things you can consume while fasting to stay in the fasted state. Adding lemon is a great idea as this will not add calories. Also, the lemon provides essential electrolytes your body needs. Most hunger pains during a fast can be controlled with lemon water.
But what if you want to sweeten the water?
In this case stevia is the best option for a natural sweetener. Again, it will not affect autophagy, hormones or digestion the key benefits of fasting.
One last point on lemon water with stevia. Water consumption actually increases your metabolic rate. It makes sense as the more hydrated you are, the faster chemical reactions in your body can occur. Water is the universal solvent and makes so many good things happen in your body.
“Rule of thumb for water consumption. Take your body weight in pounds divided by two = number of ounces of water to drink per day.” Example: 160lbs / 2 = 80 ounces per day
Be Careful Which Stevia You Buy!
If you choose to use an artificial sweetener then a natural product such as stevia or monk fruit are the way to go. However, you need to ensure you buy pure natural stevia. This is important as many products add fillers that can take away from the benefits noted above.
The best options are organic, green leaf stevia. Remember stevia is 200-400 times sweeter than sugar. Therefore, to bulk products up some companies add sugars to the product. Therefore checking ingredient labels is a must!
Avoid products containing the following:
- Sugar alcohols, such as mannitol, sorbitol, xylitol, lactitol, isomalt
Dextrose and maltodextrin are actually types of sugar with calories and not good for your fast. Sugar alcohols can cause gas buildup and potentially something called SIBO. This refers to small intestinal bacterial overgrowth that can cause digestive problems.
Here is what good stevia products will include:
- Vegetable glycerin
Make sure you read the stevia label, both the active and inactive ingredients. Typically powdered forms are less processed and thus have a lower risk of having additives you do not want. The marketing teams for these products use all kind of terms like natural, fresh, whole and from the earth. Typically the word organic will indicate a product you want, but as always trust but verify.
Here are some example products that you can find on Amazon.com
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Share Your Story
Have you used stevia as a sweetener? Also, please share how you like it? Chime in below with your comments and thoughts.
They S L, et al. Effects of aspartame-, monk fruit-, stevia- and sucrose-sweetened beverages on postprandial glucose, insulin and energy intake. Clinical Studies and Practice. 2016:13:450-457.