Chilling your carbs could modestly slow their digestion

Chilling cooked rice, pasta or potatoes can increase the amount of resistant starch and has been shown in some studies to lower post-meal blood sugar; evidence that this reliably reduces calorie intake or produces meaningful weight loss is limited.

Wellness influencers have promoted cooking, chilling and sometimes reheating starchy foods as a way to reduce calories. The process they cite, called retrogradation, is real and converts some digestible starch back into resistant starch after cooling. Small studies, especially involving rice, have found that eating cooked-then-cooled foods can lead to lower post-meal blood glucose in some people. Whether those changes translate into substantial calorie loss or sustained weight loss is less clear. Key findings: - Retrogradation converts some amylopectin (easily digested starch) back into resistant starch, which digests more slowly. - Multiple studies since 2015 report that cooled, cooked rice sometimes produces lower post-meal blood glucose compared with freshly cooked rice. - Evidence that chilling meaningfully reduces the calorie content of foods is limited; Dr. David Ludwig is quoted saying it "doesn’t appreciably change the calorie content" but may influence hormones and appetite. - Effectiveness varies by grain variety and preparation, and some rice and grain types are naturally lower in resistant starch, which limits how much chilling can change digestion. - Retrogradation does not restore nutrients lost during refining, such as fiber, minerals and vitamins, a limitation noted by Dr. Walter Willett. Summary: Chilling cooked starchy foods can increase resistant starch and has been shown in some studies to lower post-meal blood sugar, but it does not reliably or directly reduce calories. Undetermined at this time.