Not all carbohydrates are created equal. While fiber has long been praised by health experts for its role in digestion and gut health, another lesser-known carb is gaining attention from dietitians: resistant starch. Unlike most starches, this unique type behaves much like fiber in the body—offering a range of benefits for your digestive system and beyond.
What Is Resistant Starch?
Resistant starch is a form of carbohydrate made up of glucose molecules, but it’s not digested in the same way as regular starches. Instead of breaking down in the small intestine like most carbs, it resists digestion and travels largely intact to the large intestine (colon). This quality gives it similar effects to fiber, helping your gut function more smoothly.
“Because it resists digestion, it acts more like fiber,” says Bridgette de Juan, RDN, lead dietitian at Orlando Health. “It reaches the colon intact and starts a positive chain reaction that benefits your gut.”
How Resistant Starch Works in Your Body
Resistant starch helps in two key ways. First, like insoluble fiber, it adds bulk to your stool, which helps with regular bowel movements. But its biggest impact begins once it reaches your colon.
There, resistant starch acts like a prebiotic. That means it serves as food for the good bacteria in your gut. These beneficial microbes—also known as probiotics—ferment the starch and produce short-chain fatty acids (SCFAs) as byproducts. According to Sandra Arévalo, MPH, RDN, and spokesperson for the Academy of Nutrition and Dietetics, SCFAs are vital for colon health. They fuel the cells lining your colon, strengthen your gut barrier, and reduce inflammation.
Blood Sugar Benefits
Resistant starch may also help manage blood sugar levels. Because it isn’t fully digested, less of it gets converted to sugar and enters the bloodstream. This slower digestion process results in a lower glycemic index, meaning it causes fewer spikes in blood sugar.
That’s particularly helpful for people with diabetes or prediabetes. “It allows them to enjoy carbs and still maintain better blood sugar control,” says Julia Zumpano, RD, LD, from the Cleveland Clinic’s Center for Human Nutrition.
Even for those without diabetes, resistant starch can help avoid the energy crashes or hunger pangs that often follow high-carb meals.
Where to Find Resistant Starch
You can find resistant starch naturally in certain high-fiber foods like oats, beans, and lentils. However, there’s a clever trick to creating it from refined foods like white rice and pasta.
All it takes is cooking and then cooling them. Cooling causes the starch molecules to rearrange in a process called retrogradation, which makes the starch resistant to digestion. De Juan explains that once the molecules change, they usually stay that way—even if you reheat the food. That means leftover pasta or rice may be better for your gut than freshly made dishes.
How to Add Resistant Starch to Your Diet
Here are a few easy ways to increase your intake:
Cook and chill white rice or pasta: Eat it cold or reheat it—either way, it retains the resistant starch.
Snack on green bananas: These are rich in natural resistant starch.
Add legumes like lentils and black beans: They’re high in both fiber and resistant starch.
Use oats in recipes: Overnight oats are a particularly good source.
The Takeaway
Resistant starch is a powerful ally for gut health. It functions like fiber, feeds your good gut bacteria, and may help stabilize blood sugar. Adding it to your diet is simple—and may be as easy as refrigerating your rice or making a bowl of overnight oats.
For a healthier gut and smoother digestion, this under-the-radar carb might just be your new best friend.
