People fast for different reasons and in different ways, but many have seen results from the practice. (“Fasting is a superpower. And it costs nothing,” wrote author Jeannette Winterson earlier this year about her own experience with the practice.) That’s the good news; the bad news is that it’s not always obvious whether fasting is worth it for its own sake or simply because it reduces overall calorie intake. Now, however, a group of scientists is closer to understanding exactly what fasting does to the human body—and why it may be beneficial.

As NatureAs Max Kozlov writes, a recently published study of fasting in mice has shown that fasting – or more specifically breaking the fast – has health benefits. MIT biologist Ömer Yilmaz studied the effects of fasting on stem cells and found that during fasting, in Kozlov’s words, these cells “start burning fats instead of carbohydrates as an energy source.” This, in turn, helped the body repair damage to the mice’s intestines.

Yilmaz was initially drawn to this research because it turns the usual discussion about fasting on its head. “There is so much emphasis on fasting and the duration of fasting that we have somehow overlooked the other side of the equation: What happens in the satiated state?” he said Nature.

Still, the research has also opened some troubling doors, including the discovery that fasting can accelerate the development of precancerous lesions in mice. This still leaves some questions unanswered, including whether these findings are even applicable to humans. Yilmaz said Nature that his next steps will be a clinical trial in human patients – which could tell us a lot about the risks and benefits of a temporary break from eating.