{ "format_version": 3, "claim_formal": { "subject": "swimming after eating", "property": "whether swimming within 30 minutes of eating causes dangerous cramps", "operator": ">=", "operator_note": "This is a disproof. The claim asserts a causal link: eating + swimming within 30 min = dangerous cramps. 'Dangerous' implies cramps severe enough to cause drowning or serious injury. We seek >= 3 independent authoritative sources that reject this causal claim. The claim is a compound assertion: (1) swimming after eating causes cramps, AND (2) those cramps are dangerous. If either sub-claim is rejected by medical consensus, the overall claim is disproved.", "threshold": 3, "proof_direction": "disprove" }, "claim_natural": "You must wait at least 30 minutes after eating before swimming or you will suffer dangerous cramps.", "evidence": { "B1": { "type": "empirical", "label": "Duke Health: myth that blood diversion causes dangerous cramps is unfounded", "sub_claim": null, "source": { "name": "Duke Health (Duke University Health System)", "url": "https://www.dukehealth.org/blog/myth-or-fact-should-you-wait-swim-after-eating", "quote": "the blood going to your digestive tract after eating steals the blood needed to keep your arms and legs pumping during swimming is unfounded" }, "verification": { "status": "verified", "method": "full_quote", "coverage_pct": null, "fetch_mode": "live", "credibility": { "domain": "dukehealth.org", "source_type": "unknown", "tier": 2, "flags": [], "note": "Unclassified domain \u2014 verify source authority manually" } }, "extraction": { "value": "verified", "value_in_quote": true, "quote_snippet": "the blood going to your digestive tract after eating steals the blood needed to " } }, "B2": { "type": "empirical", "label": "UAMS Health: no medical evidence supports the myth", "sub_claim": null, "source": { "name": "UAMS Health (University of Arkansas for Medical Sciences)", "url": "https://uamshealth.com/medical-myths/do-you-have-to-wait-30-minutes-after-eating-before-swimming/", "quote": "there is no medical evidence to support the myth" }, "verification": { "status": "verified", "method": "full_quote", "coverage_pct": null, "fetch_mode": "live", "credibility": { "domain": "uamshealth.com", "source_type": "unknown", "tier": 2, "flags": [], "note": "Unclassified domain \u2014 verify source authority manually" } }, "extraction": { "value": "verified", "value_in_quote": true, "quote_snippet": "there is no medical evidence to support the myth" } }, "B3": { "type": "empirical", "label": "Britannica: science does not support the food-drowning link", "sub_claim": null, "source": { "name": "Encyclopaedia Britannica", "url": "https://www.britannica.com/story/is-it-really-dangerous-to-swim-after-eating", "quote": "The chances of suffering a stomach cramp while swimming are remote, regardless of when the swimmer last ate" }, "verification": { "status": "verified", "method": "full_quote", "coverage_pct": null, "fetch_mode": "live", "credibility": { "domain": "britannica.com", "source_type": "reference", "tier": 3, "flags": [], "note": "Established reference source" } }, "extraction": { "value": "verified", "value_in_quote": true, "quote_snippet": "The chances of suffering a stomach cramp while swimming are remote, regardless o" } }, "B4": { "type": "empirical", "label": "International Life Saving Federation: no evidence eating before swimming increases drowning risk", "sub_claim": null, "source": { "name": "International Life Saving Federation (ILSF)", "url": "https://www.ilsf.org/wp-content/uploads/2018/11/MPS-18-2014-Eating-before-Swimming.pdf", "quote": "eating before swimming does not increase the risk of drowning" }, "verification": { "status": "not_found", "method": null, "coverage_pct": null, "fetch_mode": "wayback", "credibility": { "domain": "ilsf.org", "source_type": "unknown", "tier": 2, "flags": [], "note": "Unclassified domain \u2014 verify source authority manually" } }, "extraction": { "value": "not_found", "value_in_quote": false, "quote_snippet": "eating before swimming does not increase the risk of drowning" } }, "A1": { "type": "computed", "label": "Verified source count meeting disproof threshold", "sub_claim": null, "method": "count(verified citations) = 3", "result": "3", "depends_on": [] } }, "cross_checks": [ { "description": "Multiple independent sources consulted", "n_sources_consulted": 4, "n_sources_verified": 3, "sources": { "duke_health": "verified", "uams_health": "verified", "britannica": "verified", "ilsf": "not_found" }, "independence_note": "Sources are from different institutions: Duke University Health System, University of Arkansas for Medical Sciences, Encyclopaedia Britannica, and the International Life Saving Federation. These represent independent medical, academic, and reference organizations.", "fact_ids": [] } ], "adversarial_checks": [ { "question": "Is there any peer-reviewed study showing that eating before swimming causes dangerous cramps or drowning?", "verification_performed": "Searched for 'eating before swimming cramps dangerous evidence support' across medical databases and general web. Reviewed results from Duke Health, UAMS, Mayo Clinic, Red Cross, Britannica, ILSF, and multiple other medical sources.", "finding": "No peer-reviewed study was found that supports the claim. Multiple sources explicitly state that no documented case of drowning caused by swimming on a full stomach has ever been recorded in medical literature.", "breaks_proof": false }, { "question": "Do any major medical or safety organizations recommend waiting 30 minutes after eating before swimming?", "verification_performed": "Searched for current recommendations from American Academy of Pediatrics, American Red Cross, International Life Saving Federation, and Mayo Clinic regarding eating and swimming.", "finding": "Neither the American Academy of Pediatrics nor the American Red Cross makes any specific recommendation about waiting after eating before swimming. The ILSF explicitly states the recommendation is unfounded. The 2011 Red Cross Scientific Advisory Council review found no evidence of danger.", "breaks_proof": false }, { "question": "Could strenuous competitive swimming after a large meal pose some risk, even if recreational swimming does not?", "verification_performed": "Searched for 'competitive swimming eating cramps exercise intensity' to check if the claim has any validity for extreme exercise conditions.", "finding": "Some sources note mild discomfort (nausea, minor cramps) is possible during vigorous exercise after eating, but characterize this as inconvenient, not dangerous. No source describes exercise-associated cramps after eating as a drowning risk. The claim specifies 'dangerous cramps,' which is not supported even for strenuous swimming.", "breaks_proof": false } ], "verdict": { "value": "DISPROVED", "qualified": true, "qualifier": "unverified_citations", "reason": null }, "key_results": { "n_confirmed": 3, "threshold": 3, "operator": ">=", "claim_holds": true }, "generator": { "name": "proof-engine", "version": "0.10.0", "repo": "https://github.com/yaniv-golan/proof-engine", "generated_at": "2026-03-28" }, "proof_py_url": "/proofs/you-must-wait-at-least-30-minutes-after-eating-bef/proof.py", "citation": { "doi": null, "concept_doi": null, "url": "https://proofengine.info/proofs/you-must-wait-at-least-30-minutes-after-eating-bef/", "author": "Proof Engine", "cite_bib_url": "/proofs/you-must-wait-at-least-30-minutes-after-eating-bef/cite.bib", "cite_ris_url": "/proofs/you-must-wait-at-least-30-minutes-after-eating-bef/cite.ris" }, "depends_on": [] }