Quick Answer
Yes, you can use sweeteners during intermittent fasting as they do not contain calories or raise insulin levels. Popular options like stevia, erythritol, and aspartame will not break your fast. Just avoid sweeteners containing calories like sugar, honey, and agave.
What is Intermittent Fasting?
Intermittent fasting involves cycling between periods of fasting and eating. It is an eating pattern, not a diet. There are several popular intermittent fasting schedules:
- 16/8 method: Fast for 16 hours per day, eat during the other 8 hours.
- Eat-Stop-Eat: Fast for 24 hours once or twice per week.
- 5:2 diet: Eat normally 5 days per week, fast 2 days per week.
Intermittent fasting has numerous health benefits including better weight control, improved metabolism, heart health, brain function and reduced inflammation.
The Role of Fasting
The point of intermittent fasting is to spend time in the fasted state. This is when your body is not digesting or absorbing food and shifts into fat burning mode.
Consuming calories during your fast will take your body out of the fasted state. It’s best to avoid caloric beverages like coffee with milk and cream or juice.
However, you can drink calorie-free beverages like water, unsweetened tea and black coffee. This allows you to remain in the fasted state while getting hydration.
Using Sweeteners During Fasts
With calorie-free sweeteners, you can sweeten up your fasting beverages without affecting your intermittent fasting results.
The key is choosing options that do not stimulate insulin secretion in the body. Spikes in insulin take your body out of the fasted state.
Here are the best sweetener options for intermittent fasting:
Stevia
Stevia is a natural sweetener extracted from the leaves of the stevia plant. It provides sweetness without any calories or carbohydrates.
Numerous studies show stevia does not impact insulin levels, so it will not interfere with fasting (1, 2).
Erythritol
Erythritol is a sugar alcohol that is almost entirely absorbed before it enters the bloodstream. So it does not affect insulin or blood sugar (3).
It contains just 0.24 calories per gram, allowing it to sweeten beverages without adding notable calories.
Monk Fruit Extract
Monk fruit extract comes from an Asian fruit. The sweet components, called mogrosides, pass undigested through the body without elevating insulin (4).
With zero calories and carbs, monk fruit extract is highly suitable for intermittent fasting.
Aspartame
Aspartame is an artificial sweetener used in many diet beverages. Though controversial, studies show it does not raise insulin levels (5).
At 4 calories per gram, a packet or two can sweeten coffee without disrupting your fast.
Sweeteners to Avoid
Here are some sweeteners that can break your fast during intermittent fasting:
Table Sugar
Plain white sugar contains 16 calories and 4 grams of carbs per teaspoon. It will spike your insulin levels and supply your body with energy, taking you out of the fasted state.
Honey
Honey is slightly less concentrated than sugar, with 21 calories and 5.5 grams of carbs per teaspoon (6). But it can still inhibit fat burning during your fast.
Agave Nectar
Agave nectar is marketed as a healthy alternative to refined sugar. However, it is very high in fructose and calories, with 20 calories and 5 grams of carbs in a teaspoon (7). It should be avoided when fasting.
Maple Syrup
Maple syrup provides nutrients like magnesium and zinc. Nonetheless, it is still high in sugar and calories, with 17 calories and 4 grams of carbs in each teaspoon (8).
Watch Out for Hidden Sugars
When using sweeteners during intermittent fasting, it pays to read labels carefully.
Many products contain added sugars that can disrupt your fast, including:
- Flavored creamers
- Syrupy coffee blends
- Bottled teas
- Flavored sparkling waters
- Protein and meal replacement shakes
Avoid anything with calories, carbohydrates or sugar alcohols like maltitol that may impact insulin.
How Much Sweetener Can You Use?
There is no strict cutoff for how much no-calorie sweetener you can use and remain in the fasted state. But moderation is wise. Here are some guidelines:
- Stick to 1-2 packets of stevia, aspartame or other sweetener per beverage.
- Read recommendations and don’t exceed acceptable daily intake levels.
- Avoid heavily sweetened drinks that may cause gastrointestinal issues.
- Consider slowly reducing your use of sweeteners to break reliance on sweets.
Focus on unsweetening your palette over time rather than heavily sweetening allowed beverages during fasting.
Other Tips for Fasting Beverages
Here are some other tips for getting through fasting periods without sweeteners if needed:
- Flavor drinks with lemon, lime, mint, coffee or tea.
- Stay very hydrated to help with hunger and cravings.
- Opt for chilled beverages to help them seem more palatable.
- Consider sparkling water or carbonated seltzer for refreshing bubbles.
- Dilute juice or milk to minimize calories and carbs.
Relying less on sweeteners may better align with the spirit of fasting. But calorie-free sweeteners are generally considered safe for fat burning.
Should You Use Sweeteners While Fasting?
Here is a summary of the key points on using sweeteners during intermittent fasting:
| Sweeteners | During Fasts? |
|---|---|
| Stevia | Yes |
| Erythritol | Yes |
| Monk Fruit | Yes |
| Aspartame | Yes |
| Sugar | No |
| Honey | No |
| Agave | No |
The key is avoiding sweeteners that add notable calories or spike insulin levels. Aim for just small amounts of allowed sweeteners to limit reliance on sweets.
Should You Fast with Coffee?
Many people depend on coffee for energy, focus and fat burning benefits while fasting. The key is keeping it low in calories. Here are some tips:
- Enjoy plain black coffee or espresso.
- Add calorie-free flavor with cinnamon.
- Use stevia or erythritol if you need sweetness.
- Opt for unsweetened nut milk instead of cream.
- Avoid sugar, flavored syrups and sweetened creamers.
Coffee itself does not appear to affect fasting, so feel free to drink it black or with allowed sweeteners (9).
Some people experience appetite stimulation or acidity from coffee. If this occurs, switch to tea or limit intake.
Should You Fast with Tea?
Enjoying tea during fasting windows is fine as long as you avoid added milk, cream or sweeteners with calories.
Good options include:
- Plain green tea or black tea.
- Herbal teas like chamomile, peppermint and hibiscus.
- Iced tea unsweetened or with allowed sweeteners.
The antioxidants and polyphenols in many teas may provide additional benefits while fasting. Just avoid any added sugars or calories.
Sample Fasting Beverages
Here are some ideas for tasty, filling and permitted beverages to get you through your intermittent fasting windows:
Plain or flavored sparkling water
Try lemon, lime, orange or berry flavored seltzer waters. Avoid sweetened varieties.
Black coffee
Enjoy your morning joe plain or add cinnamon for flavor.
Iced tea
Brew plain or flavored tea and chill overnight for refreshing, unsweetened iced tea.
Diluted juice
For a hint of sweetness, mix a splash of 100% fruit juice into plain sparkling water.
Bone broth
Sip on bone broth for electrolytes, protein and satiating fat.
Herbal tea
Try soothing teas like peppermint, ginger or chamomile.
Electrolyte drinks
Replenish electrolytes with low-calorie sports drinks or DIY combinations.
Coffee frappé
Blend cold brew coffee, ice and a dash of vanilla whey protein powder.
Should You Use MCT Oil?
Medium chain triglycerides (MCTs) like coconut oil contain fatty acids that may provide energy and suppress appetite during fasting (10).
But with around 120 calories per tablespoon, using MCT oil may inhibit fat burning. Limit to just a teaspoon blended into coffee if needed for an energy boost and to suppress hunger.
Shopping for Fasting-Friendly Sweeteners
When shopping for intermittent fasting approved sweeteners, read labels closely and watch the carbs.
Good options include:
- Pure liquid stevia extract.
- Pure erythritol or Swerve brand.
- Monk fruit extract without added sugar.
- Aspartame sweeteners like Equal or Sweet’N Low.
Avoid sweeteners with calories, carbohydrates, sugar alcohols other than erythritol and ingredients like molasses, honey or cane sugar.
Conclusion
Using no-calorie sweeteners during intermittent fasting is perfectly fine. They allow you to reap the benefits of fasting while avoiding hunger and cravings.
Good options include stevia, erythritol, monk fruit and aspartame. Just avoid sugar, honey and other sweeteners with calories.
Focus on unsweetening your taste buds over time. But enjoy calorie-free sweeteners in moderation if needed while you transition to black coffee, plain tea and other unsweet beverages.