Tracking my cognition biomarkers across 3 years of fasting – including results from my 7-, 9-, and 10-day water fasts. Scores dip at the end of every extended fast (85, 78, 78) and rebound back within weeks of refeeding (90, 82).

Cognition Biomarkers

  • Jun 30, 2023 - 88

  • Dec 17, 2024 - 87

  • Feb 11, 2025 - 85 (end of 9-day fast)

  • Sep 4, 2025 - 78 (end of 10-day fast)

  • Oct 14, 2025 - 90 (after refeeding)

  • Jul 25, 2026 - 87 (before 10-day fast)

  • Aug 6, 2026 - 78 (end of 10-day fast)

  • Aug 18, 2026 - 82 (after refeeding)

Cortisol

Cortisol, µg/dL

  • Jan 27, 2023 - 14

  • Jun 30, 2023 - 13.7

  • Dec 17, 2024 - 10.8

  • Feb 11, 2025 (9-day fast) - 14.1

  • May 27, 2025 - 8.5

  • Sep 4, 2025 (10-day fast) - 18.5

  • Oct 14, 2025 - 10.8

Glucose

Glucose, mg/dL

  • Jan 27, 2023 - 88

  • Jun 30, 2023 - 89

  • Dec 17, 2024 - 88

  • Feb 11, 2025 (9-day fast) - 64

  • Sep 4, 2025 (10-day fast) - 63

  • Oct 14, 2025 - 88

HbA1c

HbA1c, %

  • Jan 27, 2023 - 5.5

  • Jun 30, 2023 - 5.5

  • Dec 17, 2024 - 5.5

  • Feb 11, 2025 (9-day fast) - 5.3

  • Sep 4, 2025 (10-day fast) - 5.3

  • Oct 14, 2025 - 5.4

Insulin


Insulin, µIU/mL

  • Dec 17, 2024 - 2.8

  • Feb 11, 2025 (9-day fast) - 0.2

  • May 27, 2025 - 1.4

  • Sep 4, 2025 (10-day fast) - 1.5

  • Oct 14, 2025 - 3.6

Vitamin B12

Vitamin B12, pg/mL

  • Jan 27, 2023 - 580

  • Jun 30, 2023 - 472

  • Dec 17, 2024 - 520

  • Feb 11, 2025 (9-day fast) - 1,548

  • May 27, 2025 - 529

  • Sep 4, 2025 (10-day fast) - 1,605

  • Oct 14, 2025 - 400

Folate

Folate, ng/mL

  • Jan 27, 2023 - 12.6

  • Jun 30, 2023 - 12.9

  • Dec 17, 2024 - 18.8

  • Feb 11, 2025 (9-day fast) - 19.4

  • May 27, 2025 - 18.8

  • Sep 4, 2025 (10-day fast) - 16

  • Oct 14, 2025 - 18.8