The content below is the authoritative list of publications, regulatory bodies, and retailers GFC draws from. If a source is not on this list, it is not used.
GFC publishes this for two reasons. First, transparency: anyone reading a GFC article should be able to see exactly where our facts come from and judge the quality of those sources for themselves. Second, discipline: a fixed source list is the simplest way to prevent the slow drift toward lower-quality citations that happens when no one is watching.
Tier A: Regulatory and scientific authorities
The primary sources of truth for drug approvals, health claims, clinical guidelines, and nutrition science at the EU and international level.
European Medicines Agency (EMA) — drug approvals, safety updates, and assessment reports for medicines authorized for use in the European Union. Used for all GLP-1 medication facts (semaglutide, tirzepatide, liraglutide, oral semaglutide).
European Food Safety Authority (EFSA) — scientific opinions on food, nutrition, and health claims.
- Main site: efsa.europa.eu
- EFSA Journal (official Wiley mirror, fetchable when main site blocks): efsa.onlinelibrary.wiley.com
Note: EFSA's main site frequently blocks automated requests with 403 errors. The EFSA Journal is officially hosted on Wiley Online Library at the second URL. Both contain the same authoritative content; the Wiley mirror is the practical access point for fetching EFSA opinions.
EUR-Lex — official journal of the European Union. The source for Commission Regulations, including the regulations that authorize EFSA health claims.
World Health Organization (WHO) — global health guidance, including dietary fiber recommendations and obesity classifications.
Cochrane Library — systematic reviews of clinical evidence. Used for evidence synthesis on fiber, GLP-1 medications, and related health interventions.
Tier B: Medical and scientific publications
Peer-reviewed journals and reputable medical press used for clinical evidence, study reporting, and contextual coverage of regulatory developments. We start with a tight list and expand only when a specific need is documented.
Peer-reviewed journals:
- The Lancet (thelancet.com)
- The New England Journal of Medicine (nejm.org)
- BMJ (bmj.com)
- JAMA and the JAMA Network (jamanetwork.com)
- Nature and Nature Medicine (nature.com)
- Gut (BMJ Journals) (gut.bmj.com)
- Gastroenterology (gastrojournal.org)
- The American Journal of Clinical Nutrition (ajcn.nutrition.org)
- Annals of Internal Medicine (acpjournals.org/journal/aim)
- Diabetes Care (diabetesjournals.org/care)
- Nutrients (mdpi.com/journal/nutrients)
- Cell (cell.com)
- Nature Reviews Gastroenterology & Hepatology (nature.com/nrgastro)
- Diabetes, Obesity and Metabolism (onlinelibrary.wiley.com/journal/14631326)
- Gut Microbes (tandfonline.com/journals/kgmi20)
- Journal of Nutrition (academic.oup.com/jn)
- American Journal of Gastroenterology (journals.lww.com/ajg)
- Journal of Gastroenterology and Hepatology (onlinelibrary.wiley.com/journal/14401746)
Medical and pharmaceutical press:
- Reuters Health (reuters.com)
- STAT News (statnews.com)
- Endpoints News (endpts.com)
- FiercePharma (fiercepharma.com)
- Pharmaceutical Technology (pharmaceutical-technology.com)
Anything fetched from a Tier B source must be cross-referenced against a Tier A source before being stated as fact in a GFC article. Tier B is used to find and contextualize developments; Tier A is used to confirm them.
Country sources
Each country section lists the national regulatory bodies, dietary authorities, and reputable national medical press for that market. When writing country-specific content, these are the only national sources permitted.
Germany (DE)
Regulatory and dietary authorities:
- Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM) — bfarm.de
- Gemeinsamer Bundesausschuss (G-BA) — g-ba.de
- Bundesamt für Verbraucherschutz und Lebensmittelsicherheit (BVL) — bvl.bund.de
- Deutsche Gesellschaft für Ernährung (DGE) — dge.de
- Robert Koch-Institut (RKI) — rki.de
National medical press:
- Deutsches Ärzteblatt — aerzteblatt.de
- Pharmazeutische Zeitung — pharmazeutische-zeitung.de
Spain (ES)
Regulatory and dietary authorities:
- Agencia Española de Medicamentos y Productos Sanitarios (AEMPS) — aemps.gob.es
- Agencia Española de Seguridad Alimentaria y Nutrición (AESAN) — aesan.gob.es
- Ministerio de Sanidad — sanidad.gob.es
National medical press:
- Diario Médico — diariomedico.com
- Redacción Médica — redaccionmedica.com
France (FR)
Regulatory and dietary authorities:
- Agence nationale de sécurité du médicament et des produits de santé (ANSM) — ansm.sante.fr
- Haute Autorité de Santé (HAS) — has-sante.fr
- Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES) — anses.fr
- Direction Générale de la Concurrence, de la Consommation et de la Répression des Fraudes (DGCCRF) — economie.gouv.fr/dgccrf
National medical press:
- Le Quotidien du Médecin — lequotidiendumedecin.fr
- Le Moniteur des Pharmacies — lemoniteurdespharmacies.fr
United Kingdom (UK)
Regulatory and dietary authorities:
- Medicines and Healthcare products Regulatory Agency (MHRA) — gov.uk/government/organisations/medicines-and-healthcare-products-regulatory-agency
- National Institute for Health and Care Excellence (NICE) — nice.org.uk
- Food Standards Agency (FSA) — food.gov.uk
- Scientific Advisory Committee on Nutrition (SACN) — gov.uk/government/groups/scientific-advisory-committee-on-nutrition
- NHS — nhs.uk
- British Nutrition Foundation — nutrition.org.uk
- National Diet and Nutrition Survey (NDNS) — gov.uk/government/collections/national-diet-and-nutrition-survey
National medical press:
- The BMJ (already listed in Tier B; primary UK clinical voice)
- Pulse — pulsetoday.co.uk
- The Pharmaceutical Journal — pharmaceutical-journal.com
Netherlands (NL)
Regulatory and dietary authorities:
- College ter Beoordeling van Geneesmiddelen / Medicines Evaluation Board (CBG-MEB) — cbg-meb.nl
- Zorginstituut Nederland — zorginstituutnederland.nl
- Nederlandse Voedsel- en Warenautoriteit (NVWA) — nvwa.nl
- Voedingscentrum — voedingscentrum.nl
- Gezondheidsraad — gezondheidsraad.nl
National medical press:
United States (US)
The US has a structurally different regulatory environment from the European markets. The FDA replaces both EMA (drug approvals) and EFSA (food and health claims), and there is no single national dietary authority equivalent to DGE or ANSES; instead, dietary guidance is issued jointly by USDA and HHS.
Regulatory and dietary authorities:
- Food and Drug Administration (FDA) — fda.gov
- National Institutes of Health (NIH) — nih.gov
- Office of Dietary Supplements (NIH ODS) — ods.od.nih.gov
- Centers for Disease Control and Prevention (CDC) — cdc.gov
- USDA Dietary Guidelines — dietaryguidelines.gov
- Academy of Nutrition and Dietetics — eatright.org
- American Gastroenterological Association (AGA) — gastro.org
- American College of Gastroenterology (ACG) — gi.org
- American Heart Association (professional guidelines) — professional.heart.org
National medical press:
- JAMA (already listed in Tier B; primary US clinical voice)
- MedPage Today — medpagetoday.com
- Medscape — medscape.com
Australia (AU)
Regulatory and dietary authorities:
- Therapeutic Goods Administration (TGA) — tga.gov.au
- Pharmaceutical Benefits Scheme (PBS) — pbs.gov.au
- Food Standards Australia New Zealand (FSANZ) — foodstandards.gov.au
- National Health and Medical Research Council (NHMRC) — nhmrc.gov.au
National medical press:
- Medical Journal of Australia — mja.com.au
- Australian Prescriber — australianprescriber.tg.org.au
Canada (CA)
Regulatory and dietary authorities:
- Health Canada — canada.ca/en/health-canada
- Canadian Agency for Drugs and Technologies in Health (CADTH) — cadth.ca
- Canadian Food Inspection Agency (CFIA) — inspection.canada.ca
- Dietitians of Canada — dietitians.ca
National medical press:
- Canadian Medical Association Journal (CMAJ) — cmaj.ca
Sweden (SE)
Regulatory and dietary authorities:
- Läkemedelsverket (Medical Products Agency) — lakemedelsverket.se
- Tandvårds- och läkemedelsförmånsverket (TLV) — tlv.se
- Livsmedelsverket (National Food Agency) — livsmedelsverket.se
- Folkhälsomyndigheten — folkhalsomyndigheten.se
- Nordic Nutrition Recommendations (NNR), shared regional guidelines — nordicnutrition.no
National medical press:
- Läkartidningen — lakartidningen.se
Denmark (DK)
Regulatory and dietary authorities:
- Lægemiddelstyrelsen (Danish Medicines Agency) — laegemiddelstyrelsen.dk
- Sundhedsstyrelsen (Danish Health Authority) — sst.dk
- Fødevarestyrelsen (Danish Veterinary and Food Administration) — foedevarestyrelsen.dk
- Nordic Nutrition Recommendations (NNR), shared regional guidelines — nordicnutrition.no
National medical press:
- Ugeskrift for Læger — ugeskriftet.dk
Norway (NO)
Regulatory and dietary authorities:
- Statens legemiddelverk (Norwegian Medical Products Agency) — legemiddelverket.no
- Helsedirektoratet (Norwegian Directorate of Health) — helsedirektoratet.no
- Mattilsynet (Norwegian Food Safety Authority) — mattilsynet.no
- Nordic Nutrition Recommendations (NNR), shared regional guidelines — nordicnutrition.no
National medical press:
- Tidsskrift for Den norske legeforening — tidsskriftet.no
Finland (FI)
Regulatory and dietary authorities:
- Lääkealan turvallisuus- ja kehittämiskeskus (Fimea) — fimea.fi
- Terveyden ja hyvinvoinnin laitos (THL) — thl.fi
- Ruokavirasto (Finnish Food Authority) — ruokavirasto.fi
- Valtion ravitsemusneuvottelukunta (National Nutrition Council) — ruokavirasto.fi/vrn
- Nordic Nutrition Recommendations (NNR), shared regional guidelines — nordicnutrition.no
National medical press:
- Lääkärilehti — laakarilehti.fi
Product links and retailer information
Product recommendations and retailer information operate under different rules than editorial facts, because retailer pages change constantly and the failure mode is different.
Commercial sources are not yet approved. GFC has not yet built its commercial source verification system. Until that system is in place, no general retailer (dm, Rossmann, Mercadona, Boots, Holland & Barrett, Bol.com, or any other) is approved as a source for product availability, pricing, or product links. Articles that need product recommendations are written without specific retailer claims, or they wait for the commercial source system to ship.
Amazon is permitted under one strict rule, with one fallback.
The strict rule for Amazon product links: A direct Amazon product link (the kind containing an ASIN, e.g. amazon.de/dp/B08XYZ1234) may only be published if the exact URL was successfully fetched during the writing of the article and the fetch returned a live, in-stock product matching what the article is recommending. No fetch, no link. ASINs may not be constructed from memory, copied from third-party review sites, or generated based on what an Amazon URL "should" look like. The ASIN must come from a successful fetch within the current task.
The fallback for when ASIN verification fails: If the strict rule cannot be satisfied (the product page returned an error, the listing changed, the product is out of stock, or no specific product has been verified), the article uses an Amazon search URL instead. Search URLs are constructed from a query string, not from a database identifier, and they are guaranteed to work regardless of inventory state. The pattern is amazon.[tld]/s?k=[query], for example amazon.de/s?k=chicory+inulin+powder. Search URLs may always be used in place of product links.
The combination of these two rules means that every GFC Amazon link is either verified-live or search-based. A broken or fabricated Amazon link cannot make it onto the site.
How the source list is maintained
This document is updated when a new market is added to GFC's content footprint, when a regulatory body is renamed or restructured, or when an existing source ceases to meet the editorial standard. Changes are made by editing GFC_Editorial_Sources.md directly and committing the change with a note explaining what changed and why.
Sources are not added casually. The bar for inclusion is that the source is the authoritative or near-authoritative voice in its category for its market, and that it publishes information directly relevant to fiber, gut health, GLP-1 medications, dietary guidelines, or food regulation.
Source changelog:
2026-05-15: Added Journal of Gastroenterology and Hepatology (Wiley) to the Tier B peer-reviewed journals list. Added in support of citing Wang et al. 2024 "Short-chain fatty acids: bridges between diet, gut microbiota, and health" in the prebiotic-vs-probiotic post; the journal is a long-standing peer-reviewed gastroenterology publication and meets the Tier B bar.
2026-04-10: Added twelve sources following the 2026-04-10 content audit batch. Tier B additions: Cell, Nature Reviews Gastroenterology & Hepatology, Diabetes Obesity and Metabolism, Gut Microbes, Journal of Nutrition, American Journal of Gastroenterology. US national additions: American Gastroenterological Association, American College of Gastroenterology, American Heart Association (professional guidelines). UK national additions: British Nutrition Foundation, National Diet and Nutrition Survey (NDNS). Nordic regional addition: Nordic Nutrition Recommendations (NNR), added to all four Nordic country sections. Mayo Clinic and EUFIC considered and explicitly rejected: Mayo Clinic does not meet the peer-reviewed or regulatory bar and should be re-sourced to primary citations; EUFIC is an industry-funded communication body and is not a regulator or peer-reviewed journal.