Does Chewing Gum Break a Fast? The Truth, Once and For All

If your goal is autophagy, put down the Double Bubble.
By Rebekah Harding
August 24, 2023

You already know that the calories in a cup of coffee with sugar or cream can kick you out of a non-eating window and limit the benefits of  intermittent fasting like staying in ketosis and triggering autophagy (the process by which your body repairs damaged cells.)

But what about a stick of Juicy Fruit? Does chewing gum break a fast, too? 


Does Chewing Gum Break a Fast?

A typical 3g stick of gum contains around 2g of sugar and 10 calories (1), though some types of bubblegum can pack 30 calories per serving (2). “Try to limit whatever you add to no more than 30 calories to minimize any negative impact to the metabolic benefits of IF,” Imashi Fernando, a registered dietitian nutritionist previously told The Edge

But there’s more to the story. The real answer to whether chewing gum breaks a fast depends on what you’re trying to achieve with IF. 

If you want to lose weight

For those who are using IF to stay in ketosis—the state in which your body burns fat instead of glucose—a few calories from a stick of sugar-free gum isn’t enough to break your fast or ketosis. 

The caveat: if you chew multiple sticks of sugar-sweetened gum, you could go over 30 calories and bump your body out of ketosis.

If you want to trigger autophagy

Autophagy, the process in which your body clears out and reuses old or damaged cell parts (3), is triggered when your cells are stressed or starved of nutrients, for example, during intermittent fasting. When your cells are deprived of external food sources, this process can also allow the body to begin to consume its own waste parts for energy. 

Clearing out this cellular junk is linked to a slew of health benefits—like reducing your biological age, preventing disease, and improving your insulin sensitivity—which can promote longevity (4). 

More research is needed to determine exactly how many calories you can get away with before autophagy halts. But some experts, like celebrity fitness and nutrition coach Thomas DeLauer, believe that even a few calories from a stick of gum can break your fast, limiting the benefits you can potentially get from autophagy.

Can you chew sugar-free gum while fasting?

Some research suggests that sugar-free gum—which typically clocks in at around 5 calories per serving—could actually improve your fast.

People who chewed sugar-free gum for an hour during their fasting window ate less once they broke the fast, according to one small 2017 randomized controlled trial (5). Reducing appetite during and after your fasting window could boost the weight loss benefits of IF (6).

Another small study found that chewing sugar-free gum for 30 during a fast had no impact on insulin levels (7). Because insulin levels drop and stabilize during your fasting window and spike during your eating window, this suggests that sugar-free gum is unlikely to break your fast.