About this video

• Video Title: They Were Wrong About Fasting... What 30 Hours Without Food Does
• Channel: Thomas DeLauer
• Speakers: Thomas DeLauer
• Duration: 00:18:36

Overview

This video explains the physiological processes and benefits that occur during a 30-hour fasting period, broken down into five distinct phases. Thomas DeLauer debunks common misconceptions about fasting, such as its negative impact on metabolism, insulin resistance, and muscle mass. He details the metabolic shifts, cellular repair mechanisms, and cognitive enhancements that can be achieved through extended fasting.

Key takeaways

• Fasting is Misunderstood: Contrary to popular belief, skipping meals and fasting do not necessarily slow metabolism, negatively impact insulin resistance, or cause muscle loss, especially within a 30-hour window.
• Five Phases of Fasting: The video outlines five phases of a 30-hour fast, detailing the metabolic and physiological changes occurring in each stage, from initial glucose burning to ketosis and cellular repair.
• Metabolic Switching: Between 12-16 hours, the body begins to decrease insulin levels and activate AMPK, signaling a switch from using glucose to tapping into stored fuel.
• Autophagy and Mitochondrial Health: Around 16-20 hours, autophagy (cellular cleanup) and mphagy (mitochondrial recycling) increase, contributing to improved metabolic health and cellular function.
• Ketosis and Brain Benefits: By 24-30 hours, the body enters ketosis, which blunts hunger, reduces inflammation, increases GABA (calming neurotransmitter), and boosts BDNF (brain-derived neurotrophic factor), leading to mental clarity.
• Gut Repair: Around 20 hours, the gut begins a repair process involving stem cells, which is facilitated by giving the digestive system a break from constant food intake.
• Muscle Sparing: Up to 36 hours, the body prioritizes sparing muscle tissue for glucose production, primarily by converting fat. Muscle loss is a risk only with prolonged fasts beyond 36 hours.
• Hydration and Electrolytes: During longer fasts, especially after 16 hours, low insulin levels can cause water excretion, making it important to supplement with electrolytes and salt.

The video references scientific literature and concepts to support its claims. Here are some specific scientific points mentioned:

• AMPK Activation: The video mentions AMPK (AMP-activated protein kinase) as an energy sensor that increases during exercise and fasting to signal the body to use stored fuel.
• Gluconeogenesis: It explains gluconeogenesis, the process where the body creates glucose from non-carbohydrate sources like fat or, less preferably, muscle, particularly around the 16-hour mark of fasting.
• Autophagy and Mphagy: The video highlights that autophagy and mphagy (a specific form of autophagy targeting mitochondria) are activated during fasting, especially after 16-20 hours, as a cellular cleanup and recycling process.
• Mitochondrial DNA: It discusses that mitochondria have their own DNA and that fasting can improve their efficiency and strength.
• Ketone Production and Brain Function: The video explains that during ketosis (after 24 hours), ketones become a primary fuel source for the brain, influencing neurotransmitters like glutamate and GABA, and increasing BDNF (brain-derived neurotrophic factor).
• Insulin Sensitivity: It states that prolonged periods of low insulin levels (around 20 hours of fasting) can improve insulin sensitivity, making the body more responsive to carbohydrates when they are consumed.
• Muscle Glycogen and Water Loss: The video clarifies that the initial decrease in muscle size during fasting is often due to the loss of stored glycogen and associated intracellular water, not significant muscle protein breakdown.
• Research on Urolithin: It mentions urolithin, a compound derived from pomegranates, and its potential to enhance mphagy, citing research and a company developing this compound.
• Metabolic Dysfunction Statistics: The video references a statistic that 94% of the US population has some degree of metabolic dysfunction, implying that fasting can help retrain the body to utilize different fuel sources.