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APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-21). The draft was written by AI, the existence of all 4 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 978 · Search date 2026-07-21 · Methodology v0.6

Cinnamon bark,
does it really help with Clinically meaningful reductions in weight, BMI, and body fat in adults with overweight or obesity?

30-Second Summary
D
Evidence Grade D · 33 · Safety caution
Cinnamon's small statistical weight signal does not amount to clinically meaningful weight or body-fat loss
What the
research shows
Cinnamon supplementation is rated D for the claim of clinically meaningful weight, BMI, and body-fat reduction in adults with overweight or obesity. Meta-analyses report statistically significant mean weight changes, but the magnitude is only about 0.7 to 1.0 kg and BMI about 0.4 to 0.5 kg/m². In a synthesis of 21 trials and 1,480 participants, body-fat reduction was not statistically significant and heterogeneity was 84% for weight, 79% for BMI, and 79% for body fat. A small surrogate change is therefore not labeled clinically meaningful weight loss; cassia-cinnamon coumarin hepatotoxicity is recorded separately under safety.
What the
ads claim
Marketing can turn a heterogeneous average difference below 1 kg into fat burning, body-fat breakdown, or visibly large durable loss. Glycemic research and polyphenol mechanisms do not substitute for evidence of clinically meaningful weight and body-fat reduction.
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Useful facts when choosing a product

  • Studies mix Cinnamomum cassia and C. verum with powders, water-soluble extracts, and capsules, so the species and daily dose should be checked.
  • Cassia cinnamon generally contains more coumarin than Ceylon cinnamon, and source and batch variation can make prolonged high-dose use a liver-safety concern.
  • Cinnamon supplements can cause heartburn, abdominal discomfort, nausea, or allergy, and glucose should be monitored when they are combined with diabetes medicines.
  • People with liver disease, those taking potentially hepatotoxic medicines, and people who are pregnant or breastfeeding should consult a clinician before high-dose cinnamon supplementation.
Gap Measurement · Verdict 978 · D 33
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

The 2022 umbrella meta-analysis by Keramati and colleagues pooled seven previous meta-analyses and reported -0.67 kg for weight, -0.45 kg/m² for BMI, and a nonsignificant -1.05 cm for waist circumference. Yazdanpanah and colleagues analyzed 21 controlled trials with 1,480 participants and estimated -0.92 kg for weight and -0.40 kg/m² for BMI, while body fat at -0.87% was nonsignificant; I-squared was 84.2% for weight, 78.9% for BMI, and 78.6% for body fat. A 2020 analysis by Mousavi and colleagues of 12 trials and 786 participants similarly reported -1.02 kg and -0.51 kg/m². These syntheses identify a statistical signal but do not demonstrate clinically meaningful obesity treatment, durable loss, or fewer complications.

02

Why this is classified as D (33)

Meta-analytic mean changes of -0.67 to -1.02 kg in weight and -0.40 to -0.51 kg/m² in BMI are statistically positive but too small to establish clinically meaningful obesity treatment. Body fat was null in a large synthesis, heterogeneity was high, and durable or clinical outcomes are absent, giving D with 33 points. Glycemic verdict 093 at B addresses a different outcome axis; coumarin hepatotoxicity and gastrointestinal effects are separate safety matters.

Counterpoint. Using culinary amounts as a spice differs from taking high-dose weight-loss supplements. Diet, physical activity, sleep, behavioral treatment, and when indicated evidence-based medicines or surgery remain the core of weight management; cinnamon does not replace them.

Rejudgment record. New verdict — Accepted statistically lower weight and BMI, but applied D because mean changes of about 0.7 to 1.0 kg and 0.4 to 0.5 kg/m² are too small for clinically meaningful loss, body fat was null in the larger synthesis, heterogeneity was high, and durable loss or clinical outcomes are absent. Existing cinnamon glycemic verdict 093 at B evaluates a different outcome axis

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
Clinically meaningful reduction in weight and BMIDPooled averages of about 0.7 to 1.0 kg and 0.4 to 0.5 kg/m² are statistically small and heterogeneous.
Clinically meaningful reduction in body fatDBody-fat reduction was nonsignificant in a 21-trial synthesis and heterogeneity was high.
Durable obesity-treatment-level loss from cinnamon aloneDNo persuasive outcome trial establishes durable loss or fewer obesity complications.

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
Keramati M et al. 2022Umbrella meta-analysis of cinnamon and obesity indices7Academic research; commercial funding not stated in the abstractBody weight, BMI, and waist circumferenceWeight changed by -0.67 kg and BMI by -0.45 kg/m², while waist circumference at -1.05 cm was not significant.Broadest synthesis with small effect size
Yazdanpanah Z et al. 2020Systematic review and meta-analysis of controlled clinical trials1,480Academic synthesis; funding varied across included trialsWeight, BMI, waist circumference, waist-to-hip ratio, and body fatWeight was -0.92 kg and BMI -0.40 kg/m², but body fat at -0.87% was nonsignificant and major analyses were highly heterogeneous.Key evidence of null body fat and high heterogeneity
Mousavi SM et al. 2020Systematic review and dose-response meta-analysis of randomized trials786Academic synthesis with varied funding across included trialsWeight, BMI, waist circumference, and fat massSmall mean differences were reported for weight at -1.02 kg, BMI at -0.51 kg/m², and fat mass at -1.02%.Replicated statistical signal with limited clinical magnitude
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Receipt — 4 References

All 4 cited sources were verified for existence at the original page (as of 2026-07-21).

Keramati M, Musazadeh V, Malekahmadi M, et al. Cinnamon, an effective anti-obesity agent: Evidence from an umbrella meta-analysis. J Food Biochem. 2022;46(8):e14166. PMID: 35365881. DOI: 10.1111/jfbc.14166.
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Yazdanpanah Z, Azadi-Yazdi M, Hooshmandi H, Ramezani-Jolfaie N, Salehi-Abargouei A. Effects of cinnamon supplementation on body weight and composition in adults: A systematic review and meta-analysis of controlled clinical trials. Phytother Res. 2020;34(3):448-463. PMID: 31800140. DOI: 10.1002/ptr.6539.
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Mousavi SM, Rahmani J, Kord-Varkaneh H, Sheikhi A, Larijani B, Esmaillzadeh A. Cinnamon supplementation positively affects obesity: A systematic review and dose-response meta-analysis of randomized controlled trials. Clin Nutr. 2020;39(1):123-133. PMID: 30799194. DOI: 10.1016/j.clnu.2019.02.017.
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Iwata N, Kainuma M, Kobayashi D, et al. The Relation between Hepatotoxicity and the Total Coumarin Intake from Traditional Japanese Medicines Containing Cinnamon Bark. Front Pharmacol. 2016;7:174. PMID: 27378929. PMCID: PMC4913087. DOI: 10.3389/fphar.2016.00174.
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Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-21 · Corrections: none

Cite this verdict

Cinnamon bark x clinically meaningful weight, BMI, and body-fat reduction in adults with overweight or obesity Evidence Grade D card
[Chamgap] Cinnamon bark x clinically meaningful weight, BMI, and body-fat reduction in adults with overweight or obesity — Evidence Grade D·33. 4 cited sources checked. Source: https://chamgap.com/en/verdicts/weight/cinnamon-bark-clinically-meaningful-weight-bmi-body-fat-loss/ · 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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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.