CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-03). The draft was written by AI, the existence of all 2 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 2043 · Search date 2026-08-03 · Methodology v0.6

Cod fillet,
does it really help with Additional weight loss during energy restriction?

30-Second Summary
C
Evidence Grade C · 45 · Safety caution
The extra 1.7 kg loss with cod five times weekly comes from one short completer analysis
People with fish allergy should avoid cod. Salted, dried, or processed cod can contain much more sodium and is not the same intervention.
What the
research shows
The grade is C with 45 points. In an eight-week trial of 126 adults with overweight or obesity assigned to 30% energy restriction, 150 g cod five times weekly produced 1.7 kg more loss than no seafood, P<.015. The main analysis included only 100 completers, and neither a confidence interval nor a validated threshold for cod's incremental effect was provided.
What the
ads claim
Cod's low-fat protein composition is factual but does not guarantee extra weight loss. Verdict 1077 is D with 30 points for EPA/DHA capsules; this verdict concerns actual cod meals during energy restriction.
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Useful facts when choosing a product

  • Cod fillet was provided as 150 g three times weekly, 450 g/week, or five times weekly, 750 g/week, for eight weeks.
  • Atlantic cod was studied, but farmed or wild origin, fresh or frozen state, and cooking method were not established in accessible reporting.
  • The FDA monitoring-table mean for total mercury in cod is 0.111 ppm, not a direct methylmercury result for the trial fish.
  • Trial-product sodium was not verified, and the result cannot be generalized to salted or dried cod.
Gap Measurement · Verdict 2043 · C 45
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Adults aged 20-40 with BMI 27.5-32.5 were randomized among no seafood, cod three times weekly, and cod five times weekly, all with 30% energy restriction. The published main analysis used 100 completers. Cod was 150 g per meal for eight weeks. No public registry number was verified. AVS R048-05 was sector-aligned funding intended to create value and industrial development in seafood; this was not recast as an author's personal conflict.

02

Why this is classified as C (45)

The approximate effect exceeded the conventional moderate threshold, but it came from one eight-week completer analysis, giving C with 45 points.

Counterpoint. C does not erase the 1.7 kg contrast; durability, full-randomized analysis, and replication are missing.

Rejudgment record. Cross-check applied — Randomized and completer counts were separated and total-treatment response was not misapplied to cod's incremental effect

Scoring profile behind this grade
EndpointPPatient-reported treatment goal - the symptom is the goal
ReplicationR1Single confirmatory trial
IndependenceI2Decisive evidence is publicly or non-profit funded
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
Adding cod five times weekly increases eight-week loss during energy restrictionCThe completer analysis found a 1.7 kg contrast.
Cod maintains long-term weight loss?Maintenance beyond eight weeks was not measured.

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 parallel dietary intervention trial100AVS R048-05, sector-aligned funding for seafood value creation and industrial developmentEight-week body-weight changeThe five-times-weekly group lost 1.7 kg more than no seafood, P<.015; dose trend P<.001; approximate d≈0.586 using the full sample's 2.9 kg weight-change SDDirect endpoint limited by completer analysis, small sample, and short duration
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Receipt — 2 References

All 2 cited sources were verified for existence at the original page (as of 2026-08-03).

Ramel A, Jonsdottir MT, Thorsdottir I. Consumption of cod and weight loss in young overweight and obese adults on an energy reduced diet for 8-weeks. Nutr Metab Cardiovasc Dis. 2009;19(10):690-696. PMID: 19356912. DOI: 10.1016/j.numecd.2008.12.013.
checked
U.S. Food and Drug Administration. Mercury Levels in Commercial Fish and Shellfish (1990-2012).
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

Cod fillet x additional weight loss during energy restriction Evidence Grade C card
[Chamgap] Cod fillet x additional weight loss during energy restriction — Evidence Grade C·45. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/weight/cod-energy-restriction-additional-weight-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.