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APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-03). The draft was written by AI, the existence of all 1 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 2105 · Search date 2026-08-03 · Methodology v0.6

Cooled and reheated rice,
does it really help with Reduced acute postprandial glycemic response?

30-Second Summary
C
Evidence Grade C · 48 · Safety caution
The tested cooled and reheated rice had more resistant starch and a lower one-meal glycemic response
Cooked rice should be cooled promptly, refrigerated, and reheated thoroughly. Prolonged room-temperature storage can permit Bacillus cereus growth and toxin formation, so the study's 10-hour room-temperature preparation should not be copied at home.
What the
research shows
The grade is C with 48 points. Resistant starch in the tested IR-64 rice increased from 0.64 g/100 g when freshly cooked to 1.65 g/100 g after 24 hours at 4°C and reheating; that is a measured composition fact. In 14 healthy adults with usable glucose data, two-hour glucose iAUC fell from 152±48.3 to 125±50.1 mmol·min/L (P=0.047). This tiny acute surrogate study does not establish long-term diabetes control.
What the
ads claim
The evidence supports more resistant starch and a lower glycemic curve at that meal. Diabetes prevention and long-term glycemic improvement require separate long-term trials.
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Useful facts when choosing a product

  • Measured resistant starch was 0.64 g/100 g freshly cooked, 1.30 after 10 hours at room temperature, and 1.65 after 24 hours at 4°C plus reheating.
  • The study used IR-64 rice and reheated the refrigerated rice with 240 mL water in a rice cooker for about 15 minutes.
  • Verdict 2011 is D with 28 points for long-term HbA1c with pressure-cooked parboiled brown rice; this verdict concerns cooling and reheating white rice and one-meal glycemia.
Gap Measurement · Verdict 2105 · C 48
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Sonia et al. compared the same IR-64 white rice freshly cooked versus cooled at 4°C for 24 hours and reheated with added water for about 15 minutes. Fifteen entered the crossover study; glucose and iAUC were analyzed in 14 after one glucose profile was excluded. Equal rice portions were served. Two-hour iAUC was 125±50.1 versus 152±48.3 mmol·min/L, P=0.047. No trial registration was verified. The Indonesian Danone Institute Foundation provided a publication grant, and authors declared no conflict.

02

Why this is classified as C (48)

A measured composition change and medium acute glycemic reduction are supported, but one small 14-person surrogate study gives C with 48 points.

Counterpoint. C does not deny the resistant-starch measurement; it limits the health-outcome extrapolation.

Rejudgment record. Cross-check applied — Measured resistant-starch increase in the tested rice and reduced acute glucose iAUC in 14 healthy adults, limited by small size, acute duration, and a surrogate endpoint

Scoring profile behind this grade
EndpointSSurrogate marker - laboratory or imaging measures
ReplicationR1Single confirmatory trial
IndependenceI1Mixed funding sources
Effect sizeE+Meets the clinically important threshold

The scoring table and the verdict agree (C).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Reduced acute glycemic response from cooled and reheated riceCA medium-sized reduction was observed in 14 analyzed participants.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1Randomized single-blind acute crossover trial plus food composition analysis14Publication grant from the Indonesian Danone Institute Foundation; underlying study funding not verifiedTwo-hour postprandial glucose incremental area under the curve125±50.1 for reheated rice versus 152±48.3 mmol·min/L for freshly cooked rice, P=0.047Direct positive evidence but a 14-person acute surrogate study
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Receipt — 1 References

All 1 cited sources were verified for existence at the original page (as of 2026-08-03).

Sonia S, Witjaksono F, Ridwan R. Effect of cooling of cooked white rice on resistant starch content and glycemic response. Asia Pac J Clin Nutr. 2015;24(4):620-625. PMID: 26693746. DOI: 10.6133/apjcn.2015.24.4.13.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-03 · Corrections: none

Cite this verdict

Cooled and reheated rice x postprandial glycemic response Evidence Grade C card
[Chamgap] Cooled and reheated rice x postprandial glycemic response — Evidence Grade C·48. 1 cited sources checked. Source: https://chamgap.com/en/verdicts/blood-sugar/cooled-reheated-white-rice-postprandial-glycemic-response/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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