Never heard of resistant starch before? Heres the deal: Resistant starch is a type of fiber found in some starchy foods, says Mindy Patterson, PhD, a nutrition researcher and assistant professor of nutrition at Texas Womens University. While most starch gets broken down into glucose, resistant starch, well, resists digestion and cant be broken down. Intrigued? There's so much more to know about resistant starch.

It could keep your gut healthy.

Studies have shown that increased resistant starch intake may lead to a more diverse (AKA healthier) gut microbiome . That's because resistant starch foods contain prebiotic fibers which actually ferment in your colon and feeds the good bacteria in your gut, Patterson explains. (For a refresher, prebiotics are food for probiotics, the good bacteria in your gut.)

Resistant starch may have long-term health benefits.

So far, the research on resistant starch is promising. In addition to promoting a healthy gut, it's been shown to increase insulin sensitivity , improve digestive health , and better blood sugar control .

To reap these benefits, Patterson recommends including a serving of one of the foods below in at least two meals per day. She also points out that these benefits are linked to long-term, regular consumption of resistant starch-you cant just eat a serving of cold potatoes and expect magic to happen.

Cooking and temperature matter.

Speaking of cold potatoes...how you cook your resistant starch foods impacts whether they're effective or not. That's because the way it's cooked can affect the structure of starch molecules. For example, when you cook a potato, heat opens up the starch granule and makes it more accessible to our digestive enzymes, Patterson says. When this happens, the starch enters the bloodstream as glucose-aka sugar.

On the other hand, when you cook a potato and then chill it, that starch granule closes up," she says. "Since it cant be broken down by enzymes-it doesnt enter the bloodstream as glucose, it enters the colon and can be fermented by bacteria. In other words, that's how it becomes a prebiotic.

That said, it varies from food to food. (Check out our prep tips for each food in the list below.)

Want to learn more about healthy eating? Here's what Biggest Loser chef Devin Alexander eats in a day:

There aren't really any downsides.

"No one has really tested for any potential negative effects of increased resistant starch intake, says Patterson, but its unlikely that there would be negative consequences for a healthy person eating a balanced diet. The current research also doesnt link resistant starch specifically to weight loss, but adequate intake of prebiotic fiber has been linked to better weight management .

Want to add more to your diet? Try these resistant starch foods:

1. Cooked, chilled potatoes

The starch in hot potatoes is easy to break down, so youll need to eat your cooked potatoes cold in order to get resistant starch. To make this palatable, Patterson suggests serving them in a potato salad. (Because, plain cold potatoes? No, thanks.)

2. Beans and legumes

Good news for those of us who dont love cold food: Serving beans and legumes hot maximizes their resistant starch content, says Patterson, although they still contain resistant starch while cold. So, youll get a little bit of resistant starch from hummus and bean salad, but more from warm dishes like chili or chana masala.

3. Green (or just ripe) bananas

As bananas ripen, much of the starch gets converted to sugar (thats why theyre sweetest when theyre super ripe and brown). So, unripe green bananas are starchy, and much of this is resistant starch. Eating less-sweet bananas may take some getting used to, but try slicing one over slightly sweet cereal, or a yogurt parfait.

4. Green plantains

Patterson also recommends green plantains as a good source of resistant starch. Similar to bananas, they contain resistant starch molecules that havent yet been converted to sugar. Cook your plantains and chill them before eating, to get the most resistant starch.

5. Reheated rice

As with potatoes, the starch in rice is converted to resistant starch as it cools. Because cold leftover rice sounds terrible, Patterson points out that reheated rice, specifically fried rice, is still high in resistant starch.

6. Jerusalem artichokes (AKA sunchokes)

Jerusalem artichokes-which actually have no relation to green artichokes-are a member of the sunflower family, sometimes called sunchokes. Theyre nutty and sweet when raw, but taste potato-y when baked. Serve them chilled to maximize resistant starch, maybe atop a colorful salad.

7. Corn tortillas

The longer you store a corn tortilla at room temperature, the more resistant starch is going to form, says Patterson. You can reheat the tortilla to eat it, but letting it sit on the counter for a few days beforehand will increase the resistant starch content.

8. Oats

While cooked and cooled oats pack the most resistant starch, you can still get quite a bit from a warm bowl of just-cooked oats. If youre already eating oatmeal for breakfast , keep it up! If not, consider swapping it in for your regular breakfast a few times a week.

9. Barley

While several cooked whole grains contain resistant starch, Patterson calls out barley as a particularly good source. Because it doesnt dry out as much as some other grains when cooked and chilled, barley is also a great candidate for cold grain salads.