Whether you’re trying to lose weight, limiting your consumption of carbohydrates, or regulating a health condition, science has come to the rescue! Since 2015, doctors have discovered that refrigerating complex carbohydrates (pasta, bread, potatoes, etc) reduces the amount of absorbed starch, lowers calories, and results in a low glucose spike. This process is called starch retrogradation where some of the starch changes its structure (resistant starch) after 24 hours of refrigeration, so only the remaining starch is absorbed. In many complex carbohydrates the main ingredient is starch, which is converted to glucose after digestion and is responsible for the spike in glucose. If there is a consistent spike in glucose over a long period of time, and insulin is not able to regulate, then individuals may end up developing type 2 diabetes. Furthermore, roughly 40 million Americans live with type 2 diabetes (CDC, 2024) and struggle to eliminate carbohydrates from their diet. As scientists and doctors discover more about how temperature affects starch, maybe Americans don’t have to give up their favorite carbohydrates.
Why do cold temperatures cause starch retrogradation? It has everything to do with the physical form starch transforms to after retrogradation, “The retrograded form is commonly classified as resistant starch type 3 (RS3). Because RS3 has increased crystalline order, it is less accessible to digestive enzymes in the small intestine” (Brad, 2026). Essentially, the longer starch is kept in cold temperatures, the more its atoms and molecules extend through the 3D structure, creating a solid that can’t be digested.
Let’s discuss more about RS3. How does this byproduct interact with the body? Well, in the normal digestive process, starch is immediately broken down upon entering the body and converted to glucose. But, with resistant starch, it creates an alternative way to access parts of the digestive process, “They pass through your small intestines mostly undigested, preventing the immediate rise in blood sugars. Once resistant starch reaches your large intestine, it ferments and feeds the beneficial gut bacteria. Over time, these healthy gut bacteria can improve blood glucose control (Dilley, 2024). Moreover, even if you don’t have health issues, it’s still beneficial to refrigerate starchy carbohydrates to receive the health benefits.
Likewise, there are a multitude of health benefits other than blood sugar control. An individual’s gut health is another example. After ignoring the small intestine, resistant starch acts as a prebiotic to bacteria in the large intestine and provides the necessary nutrients (Hendly, 2026). Additionally, an obvious fact of this process is the satiating feeling one has after eating refrigerated carbohydrates. This goes hand in hand with the decrease in blood sugar and for individuals that want to consume less calories. Because resistant starch leads to less starch broken down, fewer calories are absorbed. The key to the quality of resistant starch is how long it’s refrigerated for, so if you want to maximize the effects, you should adhere to the 24 hour rule.
At the end of the day, everyone loves carbs- vodka rigatoni pasta and sourdough bread are some of my favorites. But, with these delicious bites come the unlikeable rise in glucose, depletion in probiotics, and a desire to eat more calories than intended. Thankfully, there’s a resolution for all my molten lava cake and pastry lovers to follow.
References
Centers for Disease Control and Prevention. (2024, May 15). Type 2 diabetes. https://www.cdc.gov/diabetes/about/about-type-2-diabetes.html
Dilley, K. (2024, July 16). Does cooling starchy food after cooking really lower its calories? Ohio State Health & Discovery. https://health.osu.edu/wellness/exercise-and-nutrition/cooling-pasta-changes-starch
Hendley, J. (2026, February 23). Resistant starch: Can you make the carbs you eat a little healthier? Harvard Health Publishing. https://www.health.harvard.edu/diet-and-nutrition/resistant-starch-can-you-make-the-carbs-you-eat-a-little-healthier
Third Street Wellness. (2026, May 7). Resistant carbs are cool: How cooling starches can support carbohydrate reduction. https://www.thirdstreetwellness.com/2026/05/07/29262/resistant-carbs-are-cool-how-cooling-starches-can-support-carbohydrate-reduction
