Baked then chilled potato,
does it really help with Lower post-meal insulin response?
research showsThe grade is C with 44 points. Of the two registered primary endpoints, glucose did not differ and only insulin fell. Insulin area under the curve was 17.7% lower, but no 95% confidence interval was reported; this one-meal surrogate study of 30 completers cannot establish long-term glycemic control or diabetes prevention.
ads claimIt is true that chilling changes resistant-starch content. The experiment did not show improved HbA1c, weight, or diabetes incidence.
Useful facts when choosing a product
- Composition data cited in the paper reported mean resistant starch of 2.3 g/100 g in boiled, baked, or microwaved potatoes and 5.6 g/100 g after cooking and chilling. Retrogradation after cooling is a measurable compositional change.
- The registry specified 200 g of test food, but the paper reported 250 g peeled potato without additives; the chilled condition spent five days at 4 C.
- Potatoes are native to the Andes and entered Joseon around 1824 to 1825. Imwon Gyeongjeji records them briefly as Bukjeo in an appendix to the sweet-potato entry in Manhakji chapter 3.
- Verdict 1964 is C with 44 points for purple potato and blood pressure. This verdict concerns a different preparation and outcome, post-meal insulin.
What the research actually shows
Thirty-five overweight or obese women met the eligibility criteria, and 30 were enrolled, completed, and were analyzed in a randomized crossover trial. Each ate 250 g hot boiled russet potato and, on another visit, potato baked at 218 C for 90 minutes and chilled at 4 C for five days. The registry specified 200 g of test food, while the paper reported 250 g, a protocol-publication discrepancy. Insulin area under the curve was 17.7% lower, with insulin lower by 25.8% at 15 minutes and 22.6% at 30 minutes, while glucose area under the curve was nonsignificant. No 95% confidence intervals were reported. The Alliance for Potato Research and Education, a potato industry group, funded the study.
Why this is classified as C (44)
Glucose failed while insulin succeeded among the co-primary outcomes. This was a 30-person acute surrogate trial funded by an industry group, limiting the grade to C with 44 points.
Counterpoint. The acute insulin signal was directly measured but needs independent long-term testing for clinical meaning.
Rejudgment record. Cross-check applied — Glucose was null and insulin positive among co-primary endpoints in a 30-person acute surrogate trial funded by a potato industry group
| Endpoint | S | Surrogate marker - laboratory or imaging measures |
| Replication | R1 | Single confirmatory trial |
| Independence | I0 | Evidence comes only from manufacturer studies |
| Effect size | E+ | Meets the clinically important threshold |
| Precision | CX | No pooled confidence interval could be confirmed |
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) | Grade | Basis |
|---|---|---|
| Lower postprandial insulin response with chilled potato | C | The acute surrogate was positive, but co-primary glucose was null. |
| Lower postprandial glucose area under the curve with chilled potato | D | The registered glucose primary outcome was nonsignificant. |
Cross-check — Codex and Claude
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Study 1 | Randomized crossover single-meal trial | 30 | Potato industry funding from the Alliance for Potato Research and Education | Registered primary measures of postprandial glucose and insulin concentrations | Glucose null; insulin 17.7% lower; registered test meal 200 g versus 250 g in the paper; no 95% CI reported | Acute surrogate trial with only one co-primary endpoint positive and discrepant test-meal quantities |
Receipt — 2 References
All 2 cited sources were verified for existence at the original page (as of 2026-08-02).
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-02 · Corrections: none
Cite this verdict
[Chamgap] Baked then chilled potato x post-meal insulin response — Evidence Grade C·44. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/blood-sugar/baked-chilled-potato-postprandial-insulin-response/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
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