Fasting Explained - Everything You Need to Know About Fasting

This video provides an in-depth exploration of fasting, its scientific underpinnings, and its profound health benefits. Hosted by Spencer Smith of the "Self-Funded" podcast, the episode features Mark Testa, a chiropractor, acupuncturist, and expert in fasting and stem cells. The discussion builds upon a previous conversation about bone marrow concentrate and stem cells, extending into how fasting can be a powerful tool for metabolic health, disease prevention, and even reversal. The overarching theme is a proactive approach to healthcare, emphasizing lifestyle and dietary interventions to address the root causes of chronic conditions rather than solely focusing on "back-end" treatments.

Mark Testa shares his personal journey with fasting, including a transformative 5-day water fast that led to significant weight loss and a renewed sense of energy. He explains the science behind fasting, detailing how the body undergoes a metabolic switch from burning glucose to burning fat, leading to a state of ketosis. The conversation delves into critical cellular processes like autophagy and mitophagy, where the body cleans out old, weak cells and mitochondria, respectively, paving the way for cellular renewal. This cellular "house cleaning" is highlighted as a key benefit, with implications for reducing inflammation, preventing disease, and even mobilizing stem cells for repair.

The speakers also address the broader implications of fasting for public health, particularly in the context of the "healthcare crisis." They discuss the rampant issue of insulin resistance and pre-diabetes in America, linking high glucose levels to inflammation, microvascular damage (kidney disease, eye damage), and the upregulation of growth signals that can contribute to cancer. Dr. Jason Fung's work on reversing diabetes through fasting and low-carb diets is cited, along with Verta Health's success in this area within the self-funded healthcare space. The video concludes with practical advice for beginners, emphasizing a gradual approach to fasting, aligning with circadian rhythms, and the importance of nutrient-dense refeeding, while also cautioning against fasting for certain individuals.

Key Takeaways:

• Fasting Definition and Types: Fasting is defined as an unfed state, not starvation. It encompasses various durations, from intermittent fasting (e.g., 16-18 hours daily) to extended fasts (24-hour, 3-day, 5-day water fasts) and Fasting Mimicking Diets (FMDs).
• Metabolic Switch and Ketosis: Fasting triggers a metabolic switch, causing the body to transition from burning glucose (stored as glycogen) to burning fat for fuel. This process leads to the production of ketone bodies (e.g., beta-hydroxybutyrate) and a state of ketosis, which can enhance brain function and reduce inflammation.
• Autophagy and Mitophagy: After 24-36 hours of fasting, the body initiates autophagy, a process where it consumes and recycles weak, dying, or damaged cells, including those that could potentially turn into cancer. Mitophagy is a similar process specifically targeting old, dysfunctional mitochondria, leading to the regeneration of new, stronger mitochondria.
• Inflammation Reduction: Fasting significantly reduces inflammatory markers and insulin levels. Rampant glucose and insulin resistance contribute to systemic inflammation, which is a driver for chronic diseases such as diabetes, dementia, cardiovascular disease, and arthritis.
• Diabetes Reversal Potential: The video highlights the work of nephrologist Dr. Jason Fung, who has successfully helped patients reverse type 2 diabetes through therapeutic fasting, by reducing insulin production and mobilizing fat stores. Verta Health is also mentioned as a company achieving diabetes reversal through diet in the self-funded healthcare space.
• Impact on Abdominal Fat: Fasting is particularly effective at targeting abdominal fat, which is pro-inflammatory and, in men, can convert testosterone into estrogen via aromatase, impacting hormonal balance.
• Mtor and Amp Kinase Regulation: Fasting helps regulate key cellular signaling pathways. It periodically calms down mtor (mammalian Target of Rapamycin), a growth signaler activated by protein and glucose, which is crucial for growth but can contribute to cancer when constantly active. It also triggers AMP kinase, a nutrient sensor activated by a lack of calories, promoting energy balance.
• Stem Cell Mobilization: Studies from USC (Valter Longo's team) suggest that extended fasting (e.g., 4-5 days) can lead to the body releasing and mobilizing stem cells from the bone marrow to rebuild itself, offering a "boost" of natural repair mechanisms.
• Practical Fasting Progression: For beginners, a gradual approach is recommended, starting with a 12-hour fast (e.g., 7 PM to 7 AM), then incrementally extending the fasting window by an hour each week until reaching 16-18 hours. This helps the body become "fat adapted."
• Extended Fasting and Fasting Mimicking Diets (FMDs): Once comfortable with intermittent fasting, individuals can progress to 24-hour fasts (dinner to dinner) and then 3-day or 5-day fasts to achieve deeper ketosis and autophagy. FMDs, like ProLon developed by Valter Longo, offer a plant-based, low-carb, high-fat dietary protocol that mimics the effects of fasting while allowing some food intake, making it psychologically easier for some.
• Importance of Refeeding: Breaking a fast requires careful reintroduction of food. It's crucial to eat nutrient-dense, unprocessed foods (e.g., salads with healthy fats) and avoid large, heavy meals, as the digestive system needs to be gently reactivated.
• Who Should Avoid Fasting: Fasting is not recommended for individuals with a BMI below 18 (underweight), those with eating disorders, or anyone on insulin or Metformin without strict medical supervision due to the risk of hypoglycemia.
• Hunger Management Hacks: Strategies to manage hunger during fasting include drinking water, consuming a pinch of high-quality salt (Himalayan or Celtic sea salt), going for walks, or meditating.
• Circadian Rhythm Alignment: Aligning fasting windows with the body's natural circadian rhythm is beneficial, recommending stopping eating by 7 PM at the latest and generally 3 hours before bed, as digestion slows significantly after 6 PM.
• Challenging Food Propaganda: The speakers question long-held beliefs like "breakfast is the most important meal of the day" and the traditional food pyramid, suggesting that societal dietary advice has sometimes been contrary to optimal health.

Tools/Resources Mentioned:

• Documentary: "Fasting" by Doug Orchard (features Valter Longo and Jason Fung).
• Books: "The Diabetes Code" and "The Obesity Code" by Dr. Jason Fung.
• Health Program: Verta Health (uses low-carb diets for diabetes reversal in the self-funded space).
• Fasting Mimicking Diet: ProLon (developed by Valter Longo's team at USC).

Key Concepts:

• Fasted State: A period when the body is not consuming food.
• Intermittent Fasting (IF): Cycling between periods of eating and voluntary fasting on a regular schedule.
• Autophagy: A cellular process where the body cleans out and recycles damaged cells and cellular components.
• Mitophagy: A specific type of autophagy that targets and removes damaged mitochondria.
• Ketosis: A metabolic state where the body primarily burns fat for energy, producing ketone bodies.
• Metabolic Switch: The body's shift from using glucose as its primary fuel source to using fat.
• Insulin Resistance: A condition where the body's cells don't respond well to insulin, leading to higher blood sugar and insulin levels.
• Mtor (Mechanistic Target of Rapamycin): A protein kinase that regulates cell growth, proliferation, and survival; often activated by protein and glucose.
• Amp Kinase (AMPK): An enzyme that plays a key role in cellular energy homeostasis, activated by low energy states (e.g., during fasting).
• Gluconeogenesis: The metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates.
• Circadian Rhythm: The natural, internal process that regulates the sleep-wake cycle and repeats roughly every 24 hours.
• Fat Adaptation: The process by which the body becomes more efficient at burning fat for fuel.

Examples/Case Studies:

• Dr. Jason Fung's Clinical Work: A nephrologist who successfully helped patients with end-stage kidney disease (often due to diabetes) reverse their diabetes by implementing fasting protocols.
• Verta Health: An organization in the self-funded healthcare space that utilizes low-carb diets to achieve diabetes reversal for its members.
• Mark Testa's Personal Experience: His first 5-day water fast resulted in a 12-pound weight loss, primarily from abdominal fat, and a significant boost in energy.
• Spencer Smith's Personal Experience: Intermittent fasting helped stabilize energy, improve mental clarity, manage weight, simplify dieting, and reduce inflammation (e.g., from consuming bread).