Sardine Fasting
Episodes covering sardine fasting — protocols, research, and expert discussions.
A modified fasting protocol using 1-2 cans of sardines daily for 3-7 days to trigger autophagy while preserving muscle mass and providing essential nutrients
Sardine fasting is Dr. Dominic D'Agostino's innovative approach to getting the benefits of extended fasting, autophagy, ketosis, metabolic reset, without the muscle loss that comes with water-only fasting. The protocol provides omega-3s, protein, and nutrients while still creating enough caloric deficit to activate cellular cleanup pathways.
A practical middle ground between normal eating and water fasting. The protein is low enough to suppress mTOR and insulin while omega-3s provide anti-inflammatory benefits. Best used situationally (monthly or when feeling inflamed/sick), not as a regular diet.
Science & Mechanisms
Mechanisms:
- mTOR suppression: Low protein intake reduces mTOR signaling, enabling autophagy
- AMPK activation: Caloric deficit activates cellular energy sensor
- Ketosis induction: Low carb + caloric deficit drives ketone production
- Autophagy activation: The combination triggers cellular cleanup
- Muscle preservation: Protein prevents catabolism seen in water fasting
- Omega-3 benefits: Anti-inflammatory, neuroprotective
Key Research:
- Dom D'Agostino's protocol stems from working with Fred Hatfield ("Dr. Squat"), who used a similar approach during metastatic prostate cancer and went into remission
- Glucose Ketone Index (GKI) of 1-2 for 3-5 days correlates with maximal autophagy
- Research shows fasting-induced mTOR suppression and autophagy marker elevation (LC3B up, p62 down)
- Beta-hydroxybutyrate (BHB) from ketosis promotes both macroautophagy and mitophagy
Why Sardines Specifically:
- Complete protein (all essential amino acids)
- Very high omega-3 content (EPA/DHA)
- Low mercury (small fish, short lifespan)
- Shelf stable and portable
- Contains vitamin D, B12, selenium
- Bones provide calcium
Effect Sizes:
- Ketosis: Typically achieved by day 2-3
- Autophagy markers: Elevated by day 3-5
- Inflammation: Reduced (omega-3 effect)
- Muscle mass: Preserved vs water fasting
Limitations:
- No RCTs specifically on sardine fasting
- Mechanism extrapolated from fasting + ketogenic research
- Individual variation in response
- GKI measurement requires glucose and ketone meters
Episodes
Dr. Stephen Cabral breaks down whether sardine fasting actually delivers on its longevity promises. He argues that while sardines are one of the best protein sources available, ...
Tim Ferriss and Dr. Dominic D'Agostino go deep on ketones, brain health, and metabolic strategies in this wide-ranging episode. D'Agostino explains how ketones function not just...
Dr. Stephen Cabral examines the sardine fasting trend and explains why it doesn't qualify as true fasting from a scientific perspective. He breaks down how the high protein cont...
Ben Azadi hosts Dr. Annette Bosworth (Dr. Boz) for an in-person conversation covering the metabolic damage of sugar, insulin resistance in children, A1C testing, and the sardine...
Ben Azadi brings back Dr. Boz for a deep dive into hemoglobin A1C testing, the dawn effect, Ozempic side effects, and her sardine fasting protocol. Dr. Boz explains the full met...
Ella and Rhea from The Wellness Scoop tackle listener questions about trending health fads, including sardine fasting, the UK junk food advertising ban, and breathwork practices...