Published October 2021 on YouTube

Effects of Fasting & Time Restricted Eating on Fat Loss & Health | Huberman Lab Podcast #41

1. Fasting and Blood Glucose

Fasting and Health:Andrew Huberman discusses the impact of fasting on weight loss, muscle maintenance, organ health, genome, inflammation, exercise, cognition, mood, and lifespan. He also talks about tools that can make it as if you did not eat at all, which can be beneficial for health, weight loss, and performance.+
Blood Glucose and Mortality:Andrew discusses a study that shows how higher blood glucose is associated with mortality in humans, especially as people age. The study also highlights the difference between results in mice and humans, emphasizing the importance of distinguishing between studies performed in rodents versus humans.+

2. Science and Performance

Science and Performance:Andrew discusses the science behind ROKA's performance eyeglasses and sunglasses and how they can be worn for any activity. He also talks about InsideTracker, a personalized nutrition platform that analyzes data from your blood and DNA to help you better understand your body and meet your health goals.+
Blood & DNA Tests:Andrew discusses the importance of regular blood and DNA tests for assessing immediate and long-term health. He recommends InsideTracker for easy-to-use biomarker information and Helix Sleep for customized mattresses tailored to individual sleep needs. Listeners can use the provided codes for discounts on both services.+

3. Neuroplasticity Tools

Andrew shares a valuable resource for effective learning and teaching using modern principles of neuroplasticity. He discusses how different tools can lead to faster and more pervasive learning of various skills based on quality peer-reviewed research. The tools are listed in a plasticity super protocol that can be applied to learning and teaching in any format.+

4. Feeding, Fasting, Performance

Andrew explains the concept of time-restricted feeding and how it involves eating within a specific window of time each day. He emphasizes the importance of understanding the biological mechanisms behind this practice and how it can benefit mental and physical health.+

5. Nutrition Clarity

Nutrition Clarity:Andrew discusses a study on weight loss and nutrition, emphasizing the importance of precise definitions when discussing nutrition. The study found that there was no significant difference in weight loss between a low-fat diet and a low-carbohydrate diet with more dietary fats, as long as the number of calories burned is higher than the number of calories ingested.+
Perfect Diet:Andrew explains that while calories in, calories out is important, hormones such as thyroid hormone, insulin, growth hormone, testosterone, and estrogen also play a significant role in the calories burned component. He emphasizes that there is a perfect diet for each individual, and time-restricted feeding can have a positive impact on weight loss, fat loss, and various health parameters.+

6. Feeding-Induced Health Conditions

Eating and Fasting:Andrew explains how what and when we eat can set conditions in our body that can be good or bad for our health, especially liver and mental health. Blood glucose and insulin levels rise when we eat and go down when we don't eat. Other hormones are associated with the fasted state and the eating state.+
Eating for Health:Andrew explains how fasting and time-restricted feeding can have health benefits beyond just weight loss. He also discusses a landmark study that emphasizes the importance of the amount of food consumed, rather than the specific foods, for weight loss.+

7. Time-Restricted Feeding

Time-Restricted Feeding:Andrew discusses a landmark study by Satchin Panda on time-restricted feeding and intermittent fasting. The study, conducted on mice, showed that time-restricted feeding without reducing caloric intake prevented metabolic diseases in mice fed a high-fat diet. Andrew explains the four different conditions of the study and the remarkable results.+
Time-Restricted Eating:Andrew explains how time-restricted eating can improve health markers and even reverse negative health effects in mice. The study showed that mice who ate a highly palatable high-fat diet during a restricted feeding window of eight hours maintained or lost weight over time, whereas mice that ingested the same diet but had access to those calories around the clock gained weight, became obese, and quite sick.+

8. The Eight Hour Feeding Window

Andrew shares the backstory behind why an eight-hour feeding window was used in a study involving mice. The study required constant presence from a graduate student or post-doc to ensure the food was in the cages at specific times. The significant other of the scientist running the study forbade them from being in the lab for periods longer than 10-12 hours, which is why an eight-hour feeding window was used. Andrew also mentions that later they will discuss the impact of eating within different time frames on health parameters and weight loss.+

9. Time Restricted Feeding

Andrew explains the importance of time-restricted feeding and how it can benefit one's health by anchoring the gene systems of the body and providing a more regular circadian rhythm. He emphasizes the significance of eating during the more active phase of the day and avoiding eating during the nocturnal phase of the 24-hour cycle.+

10. Liver Health

Andrew explains how restricting your feeding to a particular window every 24 hours can enhance liver health. Eating around the clock can increase inflammatory markers and cause serious problems, while eating at restricted periods of time can activate certain processes that positively impact liver health.+

11. Fasting Basics

Andrew establishes the foundational protocol for maximizing goals through fasting. He emphasizes the importance of not ingesting any food for the first hour after waking up and for the two to three hours prior to bedtime. These pillars are well supported by research and have benefits for weight loss, metabolic health, and more.+

12. When to Start & Stop Eating

Ideal Feeding Window:Andrew discusses the ideal time for the eating window and how long it should be. He references a recent review from Satchin Panda's lab and explains that it's best to extend the sleep-related fast either into the morning or to start it in the evening.+
Fasting Benefits:Andrew explains how fasting triggers autophagy and how it benefits the body. He suggests that extending the fasting period by skipping breakfast and eating later in the day can take advantage of the deep fast during sleep.+

13. Optimal Fasting Schedule

Fasting and Eating Window:Andrew explains the importance of the timing of the eating window and how it relates to fasting. He discusses the best, better, and worst scenarios for fasting and eating windows, and how they affect the body's transition into a fasted state.+
Sleep-Related Fasting:Andrew discusses the benefits of time-restricted feeding and the importance of avoiding eating too close to bedtime to allow for sleep-related fasting. During sleep, the lymphatic system clears out metabolic debris and enhances cognition, making it beneficial to prioritize sleep and fasting.+
Optimal Intermittent Fasting:Andrew discusses the optimal feeding window for intermittent fasting, suggesting starting to eat around 10:00 AM or noon and allowing a feeding window until 6 or 8:00 PM. This schedule allows for the benefits of intermittent fasting while still being in sync with social rhythms in most cultures.+

14. Fasting and Food Volume

Andrew explains how food volume and type impact the transition from fed to fasted state during fasting. Large meals take longer to digest than small meals and foods with fats slow down gastric emptying time. It is important to establish a feeding window that can be comfortably managed and placed in a social and life context that can be managed on a regular basis.+

15. Optimal Feeding Window

Andrew Huberman discusses the importance of establishing a feeding window based on the results of the My Circadian Clock experiment. He explains how people tend to underestimate their feeding window and suggests selecting a slightly shorter eating window than is comfortable to account for the taper before entering a fasted state. He recommends an eight-hour feeding window for most people, but acknowledges exceptions.+

16. 4-6 Hour Feeding Windows

Andrew discusses the positive health effects of time-restricted feeding in humans using short feeding windows of 4-6 hours. Although these windows produce positive health effects, they tend to cause overeating, leading to weight gain. The seven to nine hour feeding window is the most beneficial for most people to adhere to on a regular basis.+

17. Early Protein Intake

Early Feeding for Muscle Growth:Andrew discusses a recent study that shows how early feeding can support muscle growth and maintenance. The study found that protein synthesis is enhanced early in the day due to the expression of the BMAL gene, making it beneficial to ingest protein before 10:00 AM if muscle hypertrophy is the main interest.+
Early Protein Intake:Andrew discusses the importance of ingesting protein early in the day for muscle maintenance and hypertrophy. The study shows that it doesn't matter when the resistance training occurs in the 24 hour cycle, but ingesting protein early in the day favors hypertrophy.+

18. How to Shift Your Eating Window

Feeding Window Importance:Andrew explains the importance of a consistent feeding window for circadian clock mechanisms and downstream effects of eating. He advises allowing a transition period to shift the feeding window gradually and maintaining a regular feeding schedule for at least 30 days. The episode highlights data from the My Circadian Clock experiment and emphasizes the importance of strict start and stop times for calorie intake.+
Consistent Feeding Window:Andrew emphasizes the importance of having a consistent feeding window for intermittent fasting to have positive effects on metabolic health. He suggests finding a feeding window that can be consistent on most days and avoiding drifting feeding windows.+

19. Accelerating Fasting

Accelerating Fasting:Andrew discusses the importance of transitioning from a fed state to a fasted state and how glucose clearing can help accelerate this process. A light walk after dinner can increase gastric emptying time and allow for a quicker transition to a fasted state.+
High-Intensity Training:Andrew explains how high-intensity interval training affects blood glucose levels and how the timing of the workout can impact its effects. He discusses how engaging in high-intensity interval training in the afternoon or evening can help lower blood glucose and transition the body into a fasted state, making it beneficial for those who want to engage in intermittent fasting.+
Fasting and Glucose:Andrew explains how intermittent fasting is not about when you eat, but extending the duration of the fasting period. He also discusses glucose disposal agents such as Metformin and berberine and their effects on blood glucose levels.+

20. Glucose Monitoring and Cellular Growth

Glucose Monitoring:Andrew discusses the benefits of using a continuous glucose monitor to track blood glucose levels and how it can help understand the impact of different foods and exercises. He also cautions against the use of glucose clearing agents like berberine and Metformin, emphasizing the importance of approaching them with caution.+
Cellular Growth vs Repair:Andrew explains how being in a fed or fasted state can either promote cellular growth or repair and clearance. This is due to the two different pathways of cell growth and cell breakdown and repair associated with AMPK and MTOR/PSX.Show transcript +

21. Intermittent Fasting Benefits

Andrew explains how intermittent fasting can improve gut health by promoting healthy gut microbiota and reducing the amount of lactobacillus present in the gut. Time-restricted feeding can assist people with irritable bowel syndrome and other forms of colitis by impacting the expression of clock genes and having a direct effect on the mucosal lining.+

22. Non-Alcoholic Fatty Liver

Andrew explains how brown fat, a healthy type of fat in our body, can positively impact liver health and reduce the risk of non-alcoholic fatty liver disease. He shares insights on how cold exposure and time-restricted feeding can increase brown fat stores, potentially reversing the disease.+

23. Hormones and Feeding

Hormones and Time-Restricted Feeding:Andrew discusses the effects of time-restricted feeding on hormones, specifically testosterone, and how it can lead to significant decreases in free testosterone. He also highlights a study that explored the effects of time-restricted eating on athletic performance, immune function, and body composition.+
Hormone Health:Andrew discusses the importance of understanding your hormonal profile and how time-restricted feeding can affect it. He explains that while testosterone levels may decrease, cortisol levels can also be lowered, which can offset the effects of testosterone. He recommends an eight-hour feeding window for optimal hormone health, even for high-performing athletes and those with high levels of stress.+

24. Fertility

Andrew discusses the relationship between feeding, body fat stores, and hormones. He explains how leptin signals the brain to turn on puberty and how sufficient leptin signaling is needed to maintain ovulation in women. He also mentions how fasting or extreme exercise plus fasting can reduce testosterone and impact sperm counts and fertility in men. Andrew advises taking time to transition into a time-restricted feeding window and determining what works best for individual hormone health.+

25. Eight Hour Feeding

Andrew explains the basis for the eight hour feeding window and highlights a study that shows it produces weight loss without calorie counting. The study also reduced blood pressure and has been tested in obese and non-obese adults, as well as children, making it a good rule of thumb for time-restricted feeding.+

26. Eating Every-Other-Day

Andrew discusses various fasting patterns such as alternate day fasting, five days of eating followed by two days of fasting, and time-restricted feeding. He explains the benefits and drawbacks of each pattern, including weight loss and reductions in blood glucose, but also notes that some patterns may not be feasible for most people.+

27. Adherence

Andrew discusses the issues with studies that claim different diets produce equal weight loss results due to differences in adherence. He suggests that an eating plan that works for an individual's psychological and physical state is key. Some people find it easier to fast for certain periods of the day, while others prefer portion control throughout the day.+

28. Mental Focus & Clarity

Andrew discusses how time restricted feeding and fasting can lead to mental clarity by reducing decision-making in the brain, specifically the go no-go circuitries of the basal ganglia. By knowing when to eat, individuals can avoid the constant negotiation and restriction of portion control, leading to a more straightforward approach to eating.+

29. Time-Restricted Feeding

Andrew discusses the scientific evidence that supports time-restricted feeding as a way to ensure that a significant portion of weight loss comes from body fat stores. By increasing lipases and decreasing lipid droplet associated lipolysis inhibitors, time-restricted feeding can shift the system towards burning more fat when in a caloric deficit.+

30. Fasting Rules

Fasting Rules:Andrew explains the rules of fasting and how it depends on glucose levels, when you ate, and where you are in your circadian cycle. Drinking water, tea, and black coffee won't break your fast, but sugar and simple sugars can. It's all contextual, and wearing a continuous glucose monitor is the best way to determine if you're in a fasted state.+
Fasting and Feeding:Andrew explains how to negotiate fasting and feeding windows, and how the type of food affects blood glucose and insulin levels. He emphasizes the importance of establishing a regular routine of eating and choosing the right foods for you.+

31. Sweeteners and Fasting

Andrew discusses the impact of artificial and plant-based sweeteners on fasting. While evidence is mixed, he suggests that in moderation, plant-based non-sugar sweeteners like Stevia have a minimal impact on overall blood glucose. However, some people may experience an increase in appetite just by tasting something sweet, making it harder to adhere to a feeding window.+

32. Salt for Fasting

Andrew explains how ingesting salt can help manage mental and physical state during the fasting portion of intermittent fasting, and how it stabilizes blood volume and glucose levels. A small pinch of salt in water, ideally with lemon or lime juice, can offset lightheadedness and shakiness caused by low blood sugar, and make you feel better immediately.+

33. My Circadian Clock, Zero-App

Andrew shares two excellent zero cost resources for exploring time-restricted feeding: My Circadian Clock, a website with resources on time-restricted feeding and ongoing studies, and the Zero app, which makes it easy to mark your feeding and fasting windows and track your progress.+

34. Odd (But Common) Questions

Andrew provides insights on an ideal feeding schedule and discusses frequently asked questions about fasting, such as whether brushing teeth with toothpaste breaks a fast and if a small amount of wine after dinner can break a fast. He also mentions his own experiment with wearing a continuous glucose monitor.+

35. Sauna Glucose Spike

Andrew shares his surprise discovery that going into a sauna increases his blood glucose as high as a meal due to dehydration, but he continues to use the sauna for its valuable psychological and physical health effects.+

36. The Ideal Fasting Protocol

Ideal Intermittent Fasting:Andrew discusses the ideal intermittent fasting schedule for listeners, emphasizing the importance of avoiding food for at least 60 minutes after waking up and 2-3 hours before bedtime. He also highlights the benefits of sleep-related fasting for cellular repair processes and weight loss.+
Optimal Feeding Window:Andrew explains the importance of adhering to a regular feeding window and suggests setting a slightly shorter window to account for eating outside of the designated hours. He also discusses the potential benefits of a one meal per day approach and emphasizes the role of light exposure in regulating the circadian clock.+
Maximizing Time-Restricted Feeding:Andrew Huberman discusses the ideal schedule for time-restricted feeding to maximize weight and body fat-related benefits. He suggests starting eating at 10:00 AM and stopping at 6:00 PM, but acknowledges that it may not be practical for most people. Alternatively, starting at 12:00 PM and ending at 8:00 PM seems like a reasonable schedule for some people. It's important to have a two to three-hour buffer before sleep and to consider exercise timing.+
Time-Restricted Feeding:Andrew discusses the benefits of time-restricted feeding for weight loss and physical performance. He also shares tips on glucose disposal agents, behaviors, and the importance of ingesting enough fluids. It's important to consult with a physician before making any major changes to diet or supplementation.+

37. Support and Supplements

Andrew discusses ways to support the podcast, including subscribing and leaving comments, as well as partnering with Thorne for high-quality supplements. He also shares his personal supplement regimen and offers a 20% discount for Thorne products.+