Resistant starch is a unique type of fiber with impressive health benefits.
However, only a few foods contain high amounts of it ().
Furthermore, the resistant starch in foods is often destroyed during cooking.
Most of the carbs you consume, such as those in grains, pasta and potatoes, are starches.
Some types of starch are resistant to digestion, hence the term resistant starch.
Resistant starch functions similarly to soluble, fermentable fiber, helping feed the friendly bacteria in your gut and increasing the production of short-chain fatty acids like butyrate (, , ).
Studies have shown that it can help with weight loss and benefit heart health, as well as improve blood sugar control, insulin sensitivity and digestive health (, , , ).
Interestingly, the way you prepare starch-containing foods affects their starch content, as cooking or heating destroys most resistant starches.
However, you can "recapture" the resistant starch content of some foods by letting them cool after cooking.
Although there is no formal recommendation for the intake of resistant starch, many of the studies showing health benefits used 15-30 grams per day.
Below are 9 foods that contain high amounts of resistant starch.
Oats are one of the most convenient ways to add resistant starch to your diet.
3.5 ounces (100 grams) of cooked oatmeal flakes may contain around 3.6 grams of resistant starch. Oats are also high in antioxidants and are a whole grain ().
Letting your cooked oats cool for several hours or overnight could increase the resistant starch even further.
Bottom Line: Oats are a good source of resistant starch, providing around 3.6 grams per 3.5 ounces (100 grams) of cooked oatmeal flakes.
Rice is another low-cost and convenient way to add resistant starch to your diet.
One popular preparation method is to cook large batches for the entire week.
Doing this not only saves time but also increases the resistant starch content when the rice is left to cool.Brown rice may be preferable to white rice due to its higher fiber content. Brown rice also provides more micronutrients, including manganese and magnesium ().
Bottom Line: Rice is a low-cost source of resistant starch, especially when it is left to cool after cooking.
Several healthy grains provide high amounts of resistant starch.
Although grains are often mistakenly believed to be unhealthy, natural whole grains can be a sensible addition to your diet (, ).
Not only are they a great source of fiber, they also contain important minerals and vitamins ().
Bottom Line: Natural whole grains can be excellent sources of dietary fiber and resistant starch, along with various other nutrients.
Both should be soaked and fully heated to remove lectins and anti-nutrients ().
Depending on the type of legume, they contain around 1-4 grams of resistant starch per 3.5 ounces (100 grams) after they've been cooked ().
Bottom Line: Legumes or beans are excellent sources of fiber and resistant starch. A serving may provide around 1-4 grams of resistant starch.
Potato starch is a white powder that looks similar to regular flour.
It's one of the most concentrated sources of resistant starch, with around 72% of the starches in it being resistant ().
For this reason, you only need 1–2 tablespoons per day. It's often used as a thickener or added to smoothies, overnight oats or yogurts.
It's important not to heat the potato starch. Instead, prepare the meal and then add the potato starch once the dish has cooled.
A lot of people use raw potato starch as a supplement in order to boost the resistant starch content of their diet.
Bottom Line: Potato starch is the most condensed form of resistant starch available. Try adding 1–2 tablespoons per day into yogurt or smoothies.
If prepared correctly and left to cool, potatoes are a good source of resistant starch.
It's best to cook them in bulk and allow them to cool for at least a few hours. When fully cooled, cooked potatoes will contain significant amounts of resistant starch.
In addition to being a good source of carbs and resistant starch, potatoes contain nutrients such as potassium and vitamin C ().
Remember not to reheat the potatoes. Instead, eat them cold as part of homemade potato salads or other similar meals.
Bottom Line: Cooking potatoes and then allowing them to cool significantly increases their resistant starch content.
Green bananas are another excellent source of resistant starch and fiber (, ).
Additionally, both green and yellow bananas are a healthy form of carbs and provide other nutrients such as vitamin B6 and vitamin C ().
As bananas ripen, the resistant start transforms into simple sugars like fructose, glucose and sucrose.
Therefore, you should aim to buy green bananas and eat them within a couple of days if you want to maximize your resistant starch intake.
Bottom Line: Green bananas are high in resistant starch, which gets replaced with simple sugars as the banana ripens.
Hi-maize flour is often referred to as Hi-maize fiber or Hi-maize resistant starch.
Like potato starch, Hi-maize flour is a very condensed form of resistant starch and can be easily added to yogurt or oatmeal.
Up to 50% of it is fiber, most of which is resistant starch.
Bottom Line: Hi-maize flour is a highly concentrated source of resistant starch. Try adding a tablespoon to your meal, such as yogurt.
Cooking and cooling other starches will increase their resistant starch content ().
As with the sources discussed above, it's best to heat them and then allow them to cool overnight.
This can be applied to most of the sources discussed in this article, such as rice and potatoes, as well as pasta.
One time-saving technique is to prepare a large batch of pasta, rice or potatoes on the weekend, then cool them and eat them with vegetables and proteins for complete meals during the week.