What Is Resistant Starch & How Can You Add It To Your Diet?

In a world of low-carb love, starchy foods often get a bad rap. But just like carbs aren't the enemy, starch isn't all bad, either—in fact, some can be truly beneficial to your health. Nutritionists have plenty of insight on all things resistant starches, including the benefits, types, and how to get more in your diet. 

Resistant starches are often categorized into four groups, based on the source. It's also important to note that one type of food can contain different types of resistant starches. Osteopathic doctor Christine Maren, D.O., breaks them down:  

Resistant starch is the most beneficial to gut health, compared to its counterparts: rapidly digestible starch (RDS) and slowly digestible starch (SDS). RDSes are rapidly digested in the small intestine1, according to research published in Nutrients. This causes the carbohydrates to transform into glucose and often leads to a spike in blood sugar. "These rapid and large increases in blood glucose levels can further lead to cell, tissue, and organ damage," the study says. SDSes take longer to break down than RDSes and tend to have similar benefits of low-glycemic foods2, like prolonged energy. Both alternative types of starch are absorbed much more quickly than resistant starch and therefore don't offer the same health benefits.

Resistant starches have also been shown to help manage weight, as well as metabolic and cardiovascular diseases5. 

Supplementing your diet with raw potato starch is another simple way to increase your intake of resistant starches. Although, Maren recommends focusing primarily on adding whole foods to your diet. "Bob's Red Mill Unmodified Potato Starch (not flour) can be added to smoothies or even stirred into sparkling water," she says. 

If you're seeking a top-notch source of resistant starch, look no further than these nutritious foods:

Plantains may look like bananas, but they are a starchier, less sweet version. In fact, they can be similar to potatoes in flavor, which is why plantains are commonly made into savory chips. Plantains are high in amylose, making them resistant to digestion. 

Green bananas6 are a good source of fiber; vitamins C, A and B6; as well as minerals, like potassium, phosphorus, magnesium, and zinc. They're also higher in resistant starches than ripe bananas. Since unripe bananas may be difficult to eat raw, consider freezing them for use in smoothies. 

Beans, peas, and lentils are all a good source of fiber and resistant starch, making them beneficial for digestion. In this case, their resistant starch levels increase when cooked, then cooled. 

White potatoes and sweet potatoes also contain resistant starches when cooked, then cooled. "If you don't want to eat them cold, this type of resistant starch will withstand gentle reheating as long as you keep the heat low," Maren says. Otherwise, you can toss them into fresh green salads or cold potato salads. 

Rice also falls under the third type of resistant starch because when cooled for at least 24 hours it causes starch retrogradation and increases starch content7. 

While starches and carbs may have a bad reputation, they can be an important part of a healthy diet. Aiming for starches that resist digestion can have positive impacts on the gut microbiome, and, thankfully, these foods are pretty easy to find.