One of your body’s main functions is digesting what you eat, breaking it down into nutrients it can use for energy, growth, and repair.

So you might be surprised to learn that there are foods it can’t digest—and that despite this, they are essential for your overall health.

Two such types are dietary fiber and resistant starches, plant-based carbohydrates that can help optimize your cholesterol and blood sugar levels, boost your gut health, and even possibly reduce your risk of cancer. Follow this guide to learn more about these carbs and discover how you can incorporate them into your diet.

Insoluble and soluble fiber

Most Americans don’t eat much fiber—only about 3 percent of men and less than 10 percent of women consume enough of it daily, according to the USDA. However, both soluble and insoluble fiber are essential for your overall health. The former dissolves in water and bodily fluids and feeds your gut’s good bacteria, which are believed to provide some protection against conditions like obesity and diabetes. A big benefit of soluble fiber is that it can satisfy your hunger without adding too many calories to your diet. Some good sources of it are apples, barley, beans, carrots, citrus fruits, oats, and peas.

Insoluble fiber, meanwhile, moves through your body unchanged, making it easier for food to pass quickly through your digestive system. Foods rich in this type of fiber include green beans, cauliflower, nuts, potatoes, and whole-wheat flour.

Resistant starches

As the name indicates, resistant starches are carbohydrates that are aren’t easy for your body to digest. Rather than being absorbed by your small intestine, they’re fermented, or broken down, by the bacteria in your large intestine. Adding more resistant starches to your diet may help ease constipation and lower your inflammation and colon cancer risk. These carbs are naturally present in foods like beans, legumes, nuts, seeds, whole grains, and unripe bananas.

Dietary suggestions

As indicated, simply adding more fruits, vegetables, whole grains, and nuts to your diet can improve your fiber and resistant starch intake. But if you find it difficult to know how to do so or still feel like you aren’t getting adequate amounts of these important carbs, these tips can help.

Whip up a morning smoothie
Start your day by blending fiber-filled blueberries, chia seeds, and oats with Greek yogurt and your favorite kind of milk to create a delicious and healthful smoothie.

Select fiber-rich snacks
When you need something to munch on between meals, reach for snacks like cashews, apple slices topped with a nut butter, air-popped popcorn, or whole-grain crackers with guacamole. Also seek out often overlooked sources of fiber, including roasted chickpeas, hummus, and steamed edamame.

Cool your carbs
Surprisingly, a simple way to increase the amount of resistant starches in your food is by substantially cooling carbohydrates like cooked rice, pasta, and potatoes for several hours in your refrigerator. As a bonus, this process makes leftovers with these ingredients healthier the next day.

Choose healthy meals
For a filling dinner, consider loading a bowl with some quinoa and adding toppings like spinach or kale, shaved brussels sprouts, and roasted sweet potato. Then finish it off with a light salad dressing and spices and herbs of your choice.

Take it slow
If you don’t normally consume much of these foods, be sure to add them slowly to your snacks and meals over the course of a few weeks to avoid experiencing digestive discomfort. Drinking plenty of water can also help you limit any potential issues.

Everyone knows that fruits, vegetables, and whole grains are good for you for a variety of reasons. But when you incorporate ones loaded with fiber and resistant starches into your diet, you can reap an extra reward—improved digestive health.