Do Freezing Carbs Lower the Calories You Absorb?

Scientific research suggests that altering the temperature of certain cooked carbs can change their nutritional profile. But do freezing carbs lower the calories you actually absorb, and if so, how does this process work to influence your overall calorie intake?

Quick Summary

Freezing and reheating cooked carbohydrates like rice and potatoes can increase their resistant starch content. This process reduces the number of calories the body absorbs from these foods by slowing digestion and acting more like fiber.

Key Points

• Resistant Starch Creation: Cooking, cooling, and then reheating certain starchy carbohydrates converts some digestible starch into resistant starch.

• Reduced Calorie Absorption: Resistant starch is not fully digested by the body, which leads to fewer calories being absorbed from the food.

• Blood Sugar Management: The presence of resistant starch results in a slower, more gradual rise in blood sugar levels compared to freshly cooked carbs.

• Improved Gut Health: Resistant starch acts as a prebiotic, feeding the beneficial bacteria in your large intestine and promoting gut health.

• Applicable Foods: The process works best on starchy foods like rice, pasta, potatoes, and bread, but not on all foods.

• Reheating Maintains Benefits: Reheating cooled or frozen carbs does not reverse the resistant starch formation, so the nutritional benefits are preserved.

• Dietary Tool: This method is a practical and convenient way to make certain staple foods a healthier part of a balanced diet for weight and blood sugar control.

Understanding the Calorie Question: How It Works

The idea that you can change a food's calorie content through freezing and reheating is supported by food science. When starchy foods such as rice, pasta, and potatoes are cooked and then cooled, a process called retrogradation takes place. This process alters the structure of some of the starches, converting them into resistant starch.

What is Resistant Starch?

Resistant starch is a type of starch that resists digestion in the small intestine. Unlike typical starches which are broken down into glucose and absorbed, resistant starch functions more like soluble fiber. It travels to the large intestine where it is fermented by beneficial gut bacteria. This fermentation process offers several health benefits:

• Supports Gut Health: Provides nourishment for beneficial gut bacteria.
• Stabilizes Blood Sugar: Leads to a slower and more gradual increase in blood sugar levels.
• Increases Fullness: Helps promote feelings of satiety, which can assist with weight management.
• Reduces Calorie Impact: Since the body doesn't fully digest resistant starch, the net calories absorbed from the food are reduced.

The Freezing and Reheating Connection

Cooling cooked starchy carbs initiates the formation of resistant starch, and freezing further enhances this process. Freezing cooked starchy carbs causes starch molecules to bond more tightly. This structural change largely remains even after thawing and reheating, preserving the resistant starch benefits. Reheating has been shown not to significantly reverse the formation of resistant starch.

Comparison: Freshly Cooked vs. Cooked, Cooled, and Reheated

This table highlights the differences in how the body processes fresh versus retrograded starchy carbohydrates.

Feature	Freshly Cooked Starchy Carbs (e.g., rice, pasta)	Cooked, Cooled & Reheated Starchy Carbs
Starch Structure	Mostly digestible starch.	Increased resistant starch due to retrogradation.
Digestion	Rapidly digested.	Resists digestion, acts like fiber.
Calorie Absorption	Higher calorie availability.	Lower calorie availability.
Blood Sugar Response	Can cause a rapid spike.	Slower, more gradual rise (lower glycemic index).
Gut Health	Minimal impact.	Feeds beneficial bacteria.
Satiety	Shorter periods of fullness.	Promotes longer periods of fullness.

Practical Application: Which Carbs to Freeze?

This process is most effective with specific starchy foods, as it relates to the behavior of complex starches.

Foods that benefit from freezing and reheating:

• Rice: Cook, cool completely, and freeze in portions.
• Pasta: Cool completely after boiling before freezing.
• Potatoes: Cooking, mashing, then freezing before reheating also creates resistant starch.
• Bread: Toasted bread from the freezer shows increased resistant starch.

How to Maximize the Effect

To optimize resistant starch formation:

1. Cook the carbohydrate thoroughly.
2. Cool completely to room temperature before refrigerating or freezing. Cooling for 12-24 hours is optimal.
3. Freeze in portions for easy use.
4. Reheat gently to maintain resistant starch levels.

Beyond Calories: The Gut Health Advantage

In addition to potential calorie reduction, the gut health benefits of resistant starch are significant. By nourishing gut bacteria, resistant starch helps produce short-chain fatty acids (SCFAs), such as butyrate, linked to reduced inflammation, improved immune function, and possibly lower cancer risk. This method offers holistic digestive health benefits.

Conclusion

Freezing carbs, particularly after cooking and cooling, can lower the calories you absorb by converting digestible starches into resistant starches. This process also provides significant benefits for blood sugar management and gut health. While the exact calorie reduction varies, incorporating this method for certain starchy foods is a simple way to manage weight and improve overall health.

For further information on resistant starch and gut health, you can visit the National Institutes of Health website at https://pubmed.ncbi.nlm.nih.gov/26693746/.

Frequently Asked Questions

Does freezing bread and toasting it lower the calories?

Yes, freezing white bread and then toasting it has been shown to increase its resistant starch content. This process can significantly lower the bread's glycemic index, resulting in a slower rise in blood sugar and a lower net calorie absorption.

Do I have to freeze the carbs to get resistant starch?

No, simply cooling cooked starchy carbs like pasta or rice in the refrigerator is enough to create resistant starch. However, freezing can further enhance this effect, according to some research.

Does this work for all types of food?

This effect primarily applies to starchy carbohydrates such as rice, potatoes, pasta, and bread. Freezing other food types, like meat or vegetables, does not alter their calorie count in the same way, though it does preserve their nutrients.

Can I get resistant starch by eating the food cold?

Yes, consuming the cooked and cooled starchy food cold is an effective way to get the benefits of resistant starch. However, reheating the food does not destroy the resistant starch, so you don't have to eat it cold to reap the rewards.

How much of a calorie reduction can I expect?

The exact reduction can vary based on the food and individual factors. Some studies suggest a potential reduction in absorbed calories of up to 50% for certain foods like rice. The important takeaway is that it lowers the net caloric impact, though it's not a guaranteed, specific percentage.

Is freezing the most important step for creating resistant starch?

Cooling is the most important part of the retrogradation process, which creates the resistant starch. Freezing is an excellent way to prolong storage and further solidify the new starch structure, but the initial cooling is the key conversion step.

Are there any other benefits to creating resistant starch?

Beyond a potentially lower calorie impact, resistant starch offers significant benefits for gut health by acting as a prebiotic and lowering the glycemic index, which helps stabilize blood sugar levels.