Does Refrigerating Rice Make It More Healthy?

October 26, 2025 •

3 min read

According to a 2015 study published in the Asian Pacific Journal of Clinical Nutrition, rice that is cooked, refrigerated for 24 hours, and then reheated has significantly lower glycemic response than freshly cooked rice. This surprising research reveals that refrigerating rice can indeed make it healthier by changing its starch composition.

Quick Summary

Cooling cooked rice increases its resistant starch content via a process called retrogradation, which provides prebiotic benefits for gut health and lowers its glycemic index, aiding in blood sugar control.

Key Points

Resistant Starch Boost: Refrigerating cooked rice for 12-24 hours increases its resistant starch content through a process called retrogradation.
Lower Glycemic Index: This higher resistant starch content gives refrigerated rice a lower glycemic index, leading to smaller, slower blood sugar spikes compared to fresh rice.
Improved Gut Health: Resistant starch acts as a prebiotic, feeding beneficial gut bacteria and producing short-chain fatty acids that support colon health.
Enhanced Satiety: Since resistant starch is harder to digest, it promotes a greater feeling of fullness, which can be beneficial for weight management.
Reheating is Okay: Reheating refrigerated rice does not destroy the resistant starch, allowing you to enjoy the benefits with a warm meal.
Safety First: To prevent foodborne illness from Bacillus cereus, cool cooked rice quickly and refrigerate it within one hour of cooking.

The Science Behind Refrigerating Rice

The simple act of cooling cooked rice in the refrigerator triggers a scientific process called starch retrogradation. During this process, some of the digestible starches within the rice recrystallize into a different, more complex form known as resistant starch. As the name suggests, this type of starch is “resistant” to normal digestion in the small intestine, acting more like a type of dietary fiber. It passes through to the large intestine largely intact, where it is fermented by beneficial gut bacteria.

Resistant Starch and Gut Health

The fermentation of resistant starch in the large intestine is a key factor in its health benefits. The gut bacteria feed on this starch and produce beneficial byproducts called short-chain fatty acids (SCFAs), with butyrate being the most prominent. Butyrate is the primary fuel source for the cells lining your colon, and its presence is linked to reduced inflammation and better colon health. This prebiotic effect promotes a healthier, more diverse gut microbiome, which in turn supports immune function and overall digestion.

Blood Sugar Control and Glycemic Index

Another major benefit is the impact on blood sugar levels. By converting digestible starch into resistant starch, refrigerated rice effectively lowers its glycemic index (GI). A food's glycemic index measures how quickly its carbohydrates raise blood glucose levels. Since resistant starch is not easily broken down into glucose, it causes a slower, less dramatic rise in blood sugar. For individuals with diabetes, insulin resistance, or those simply looking to manage their blood sugar, this can be a powerful dietary modification. Studies have shown that consuming cooked and cooled rice leads to a significantly reduced glycemic response compared to eating it fresh.

Comparison: Refrigerated vs. Freshly Cooked Rice


Feature	Freshly Cooked Rice	Refrigerated Rice	Key Health Implications
Starch Composition	Primarily digestible starch	Higher resistant starch content	Resistant starch provides gut and metabolic benefits.
Glycemic Index	High	Lower	Helps prevent sharp blood sugar spikes.
Digestibility	Easily and rapidly digested	Slower digestion rate	Promotes a feeling of fullness and supports weight management.
Gut Health	Neutral/Basic	Prebiotic effect (feeds good bacteria)	Supports a diverse, healthy gut microbiome.
Calorie Count	Approx. 4 kcal/gram of starch	Approx. 2.5 kcal/gram of resistant starch	Potentially leads to fewer calories absorbed per gram.
Preparation Time	Ready immediately	Requires overnight refrigeration	Requires planning ahead for a healthier outcome.
Taste & Texture	Soft and fluffy	Firmer texture, can be reheated	Personal preference plays a role, but reheating is an option.

Practical Tips for Making Healthier Rice

To maximize the health benefits of refrigerated rice while ensuring food safety, follow these steps:

Cool Quickly: After cooking, spread the rice in a thin layer on a baking sheet or in a wide, shallow container. This helps it cool rapidly, ideally within one hour, preventing the growth of harmful bacteria like Bacillus cereus.
Refrigerate for a Minimum of 12 Hours: Place the cooled rice in an airtight container in the refrigerator. The starch conversion is most effective when cooled for at least 12-24 hours.
Reheat Safely: Reheating the rice will not reverse the benefits of the resistant starch. Reheat it until it is steaming hot throughout to kill any potential bacteria. The rice should only be reheated once.
Combine with Other Foods: Enhance the meal by pairing your cooked and cooled rice with protein, healthy fats, and other sources of fiber like vegetables. This combination further helps to balance blood sugar levels and improve overall nutrition.

Outbound Link: More About Resistant Starch

For a deeper dive into the science of resistant starch and its broad health implications, you can explore this resource on Healthline.

Conclusion: The Final Verdict

Refrigerating rice does indeed make it healthier, primarily by increasing its resistant starch content. This simple cooking hack offers significant benefits, including better blood sugar control, improved gut health, and increased satiety, which can aid in weight management. While the texture may change slightly, reheating the rice does not negate these positive effects. By following safe food handling procedures, you can easily incorporate this strategy into your meal preparation and enjoy a more nutritious version of this staple food.

Frequently Asked Questions

Resistant starch is a type of carbohydrate that is not digested in the small intestine but instead passes to the large intestine where it feeds beneficial gut bacteria. It's healthier because it functions like dietary fiber, promoting gut health and helping to regulate blood sugar levels.

For optimal results, you should refrigerate cooked rice for a minimum of 12 to 24 hours. This timeframe allows for a significant conversion of digestible starch into resistant starch.

You can eat the rice cold, and some people enjoy it this way in salads. Reheating the rice is also perfectly fine and will not undo the health benefits gained from the initial cooling process.

Yes, it is safe to eat leftover rice, but proper handling is critical. Cool the rice quickly and refrigerate it within one hour of cooking to prevent the growth of harmful Bacillus cereus bacteria.

The conversion of some starch to resistant starch can slightly reduce the total calories absorbed. This is because resistant starch contains fewer calories per gram (2.5 kcal) than regular starch (4 kcal).

All starchy foods, including different types of rice (white, brown, basmati), can form resistant starch when cooked and cooled. However, the exact amount can vary based on the specific rice variety and cooking method.

Always cool cooked rice quickly and refrigerate it within one hour. Store it in an airtight container for no more than 3-4 days. If you reheat it, ensure it's steaming hot throughout, and never reheat it more than once.