Does Boiling Rice Reduce Its Calories? Separating Fact from Diet Fiction

October 7, 2025 •

4 min read

Boiling rice and then draining the starchy water is a common practice in many households, and a viral internet hack claims it can reduce calories by up to 60%. But does boiling rice reduce its calories significantly? While cooking methods can alter some aspects of rice's starch content, the overall effect on its total calorie count is more nuanced than online myths suggest.

Quick Summary

This article debunks the myth that boiling rice drastically cuts its calories, explaining how starch and water content are affected during cooking. It delves into the science of resistant starch and the specific steps required to achieve a measurable reduction in calorie availability, providing a comprehensive guide for healthier rice preparation.

Key Points

Boiling alone does not reduce calories: The calorie content of rice is determined by its starch, which is not eliminated by simply boiling and draining water.
Water absorption changes calorie density: Cooked rice has fewer calories per gram than uncooked rice because it has absorbed water, which has no calories.
Resistant starch is the key: To actually reduce absorbable calories, rice must be cooked and then cooled, which creates resistant starch.
Cool and reheat to benefit: Chilling cooked rice for at least 12 hours increases its resistant starch, and this benefit remains even after reheating.
Coconut oil can enhance the effect: Adding a small amount of coconut oil during cooking further boosts the formation of resistant starch, enhancing the calorie-reducing effect.
Combine with a balanced diet: For true weight management, pair prepared rice with lean proteins and vegetables as part of a complete nutritional strategy.
Brown rice is a better starting point: For a naturally lower glycemic index and higher fiber content, opt for brown rice from the beginning.

The Core Calorie Myth: Water vs. Starch

When you boil rice, it absorbs a substantial amount of water. This process causes the grains to swell and increase in weight. This is the source of a major misconception: comparing the calories in 100 grams of uncooked rice to 100 grams of cooked rice. Uncooked rice is calorie-dense, while cooked rice is mostly water by weight, making its calorie density (calories per gram) lower. However, the total number of calories from the original dry rice remains the same, assuming all the rice is eaten and no starchy water is discarded.

If you boil rice in excess water and then drain it, you do remove a small amount of the surface starch. This can result in a marginally lower calorie count, but the reduction is not as significant as the often-repeated claims suggest. Draining the starchy water does more to change the rice's texture—making it less sticky—than it does to create a major calorie deficit.

The Role of Starch Retrogradation and Resistant Starch

The real story behind reducing digestible calories in rice is not in the boiling itself, but in what happens after the rice is cooked. The key is a process called starch retrogradation, which leads to the formation of resistant starch (RS).

Starch is a complex carbohydrate that, when heated, turns into a digestible form. When cooked rice is cooled, particularly in the refrigerator for at least 12 hours, some of that digestible starch crystallizes and transforms into resistant starch. Resistant starch, as the name suggests, resists digestion in the small intestine and functions more like dietary fiber. This means it passes through to the large intestine, where it is fermented by gut bacteria, and fewer calories are absorbed by the body.

How to Maximize Resistant Starch and Reduce Absorbable Calories

Researchers have found methods to boost the resistant starch content even further. One technique, studied in 2015 by the American Chemical Society, involves cooking rice with a small amount of coconut oil. The fat from the oil interacts with the starch, and when combined with a cooling period, this significantly increases the resistant starch, leading to a measurable reduction in digestible calories.

To achieve this, you can follow a simple, two-step process:

Add fat: Add about a teaspoon of coconut oil for every half-cup of uncooked rice to the boiling water.
Cool it down: After cooking, refrigerate the rice for at least 12 hours. This process is essential for the retrogradation of starch to occur.

It's important to note that you don't have to eat the rice cold to get the benefit. Reheating the rice does not completely destroy the resistant starch that has formed, so you can still enjoy a hot meal with lower calorie availability.

Comparison of Cooking and Preparation Methods


Feature	Standard Boiling (Water Absorption)	Boiling with Excess Water (Draining)	Cook-Cool-Reheat Method (Resistant Starch)
Effect on Total Calories	No change to original dry rice's total calories.	Very minimal reduction from drained surface starch.	Measurable reduction in absorbable calories.
Mechanism	Rice absorbs water, increasing mass but not changing total caloric content.	Draining removes some loose surface starches and water.	Starch retrogradation upon cooling creates resistant starch, which is not digested.
Glycemic Impact	Can cause a significant spike in blood sugar, especially white rice.	Slightly lower than absorption method, but effect is minor.	Creates a lower glycemic response, better for blood sugar control.
Cooking Time	Standard.	Potentially longer with more water.	Extended due to required overnight chilling.
Best For...	General cooking where calorie counting per portion is done after cooking.	Achieve a non-sticky, fluffier texture.	Individuals focusing on weight management and blood sugar control.
Special Tools	Standard pot.	Pot and strainer.	Standard pot, refrigerator, and optional coconut oil.

Important Considerations for Your Diet

While modifying how you prepare your rice can help manage calorie intake and blood sugar, it's not a magic bullet for weight loss. An effective nutrition diet should consider the bigger picture, including portion control and pairing rice with other nutrient-dense foods. Brown rice, for example, is a whole grain that is naturally higher in fiber and micronutrients, offering a lower glycemic impact than white rice from the start. Combining rice with lean proteins and a variety of vegetables creates a balanced, satisfying meal that supports healthy weight management.

The Takeaway on Does Boiling Rice Reduce Its Calories?

The simple answer is no, boiling rice in the standard absorption method does not reduce its total calories. The calorie difference seen in cooked versus uncooked rice per 100 grams is due to water absorption, not calorie elimination. The most effective method for reducing the number of absorbable calories and managing blood sugar is cooking, cooling, and optionally reheating the rice to increase its resistant starch content. When combined with a balanced diet, this can be a smart strategy for a healthier nutritional profile.

For more nutritional guidance, you can explore resources like the NIH, which provides further information on resistant starch.

Frequently Asked Questions

While the exact percentage can vary, studies have shown that cooling rice can increase its resistant starch content, leading to a noticeable reduction in the number of calories your body absorbs. The effect is measurable but not as dramatic as some viral claims suggest.

No, reheating does not eliminate the resistant starch that has been created during the cooling process. While a slight decrease might occur, a significant amount of resistant starch remains, allowing you to enjoy reheated rice with lower absorbable calories.

Adding a bit of fat, like coconut oil, during the cooking process and then cooling the rice helps alter the starch structure more effectively. This process increases the formation of resistant starch, which is indigestible by the body.

No, resistant starch is beneficial for health. It acts like a dietary fiber, feeding beneficial gut bacteria and promoting better digestive health. It also helps regulate blood sugar levels.

For optimal results, you should cool the cooked rice in the refrigerator for at least 12 hours. This gives the starch sufficient time to undergo the retrogradation process and maximize the resistant starch content.

Cooking with the absorption method and then cooling the rice to create resistant starch is generally considered a healthier approach for managing blood sugar and calorie intake. Draining excess water removes a small amount of surface starch but is less impactful on overall calorie reduction.

Yes, the principle of creating resistant starch by cooking and cooling also applies to other starchy foods such as pasta and potatoes. Refrigerating these foods for 24 hours or more can increase their resistant starch content.