Andrew Huberman - Dr. Satchin Panda

1)      Dr. Satchin Panda, a professor at the SalkInstitute for Biological Studies discusses how restricting the times within each 24-hour cycle that we eat, also known as intermittent fasting or time-restricted feeding, can impact our overall health. He explains how everything from when we wake up to when we view light, to our eating and socializing habits, impact our biology and psychology, ultimately having a strong impact on our health. He delves into the basic science and recent clinical trials exploring time-restricted feeding, including how it can impact the health of our liver, gut, brain, mood, and cognitive ability. Dr. Panda also emphasizes the importance of clear communication and understanding on this topic, which has become a topic of debate in recent years.

2)      Satchin discusses the use of technology to regulate sleep temperature, including the eight-sleep mattress cover that can regulate temperature throughout the night. The cover can make the sleeping environment cooler at the beginning and warmer as the person wakes up. The speaker also talks about personalized nootropics from thesis, stating that people have different circuits in their brains for various tasks like focus, creativity, task-switching, and energy. The nootropics can help induce these specific states.

3)      Dr. Satchin Panda discusses the history of intermittent fasting and its different forms, including alternate day fasting, periodic fasting, and the 5:2 diet. These forms of fasting involve reducing caloric intake intentionally for at least one or two days in a week or a few days in a month, leading to health benefits, including weight maintenance and reducing signs of aging. He also explains time-restricted feeding and how it involves confining all energy intake from solid and liquid food within a consistent window of 8 to 12 hours, which has been experimentally defined and found to be doable for most people.

4)      Satchin discusses the benefits of intermittent fasting and the importance of following a consistent feeding window. Heexplains that the concept of time-restricted feeding came from the science of circadian rhythms and that our body has an internal time table that pre-programs many molecular aspects of cells, organs, and physiology. Changing our feeding times can tune our liver clock and subsequently affect our body's entire circadian system. Therefore, following a consistent feeding window can help regulate our internal clock and lead to a healthier body.

5)      Dr. Satchin explains the importance of consistency in our eating habits and its effect on our digestive system. He discusses the concept of anticipatory activity, where our body prepares for the first meal after fasting for a long time, and how changing the eating time by even a few hours can disrupt this activity. Dr. Panda highlights the significance of the anticipatory signal from the digestive system and how it could potentially help us better digest and utilize food. He also shares the example of how our digestive rhythms slow down at night, and eating at the wrong time can lead to a food hangover and ultimately affect our health.

6)      Dr. Satchin talks about the respiratory exchange ratio (RER) and how it indicates whether the body is burning glucose or fat for energy. The RER will increase immediately after consuming even a small amount of food, indicating that the body has stopped the fat-burning process and started burning carbohydrates. Dr. Panda clarifies that when referring to fat burning, it is body fat stores that are being burned, not dietary fat. In discussing caloric restriction experiments on mice and rats, Dr. Panda mentions a recent study that showed reduced calorie consumption increased lifespan, but only when the caloric intake was given as a bolus at one time, rather than ad libitum feeding with access to food all the time.

7)      Dr. Satchin discusses caloric restriction and time-restricted feeding, and their potential benefits for longevity. He explains that there is a timing component to caloric restriction, as seen in studies where mice are fed all their food within a few hours, followed by along period of fasting. Caloric restriction has been found to extend the lifespan of mice by 10%. He also mentions that there are different interpretations of the benefits of time-restricted feeding, but it can be a convenient way to eat for some people. He emphasizes that the potential health benefits of these methods go beyond weight loss, and could lead to independent benefits for longevity.

8)      Dr. Satchin discusses how time-restricted feeding can impact longevity in a study conducted on mice. The study showed that if the mice were given a caloric-restricted diet and fed only during the daytime, then they lived 20 percent longer. Furthermore, when mice were given the same number of calories during the night time (when they are supposed to eat) but within a 12 hour or two-hour time span, then they lived 35 percent longer. However, despite looking at a variety of biomarkers, none of them could predict which mice would live longer suggesting that there may be biomarkers related to longevity that have not yet been discovered. It was also interesting to note that body weight and composition did not differ across any of the groups.

9)      Dr. Satchin discusses the risks of very short time-restricted feeding or one meal a day, specifically in regards to female athletes. The disruption of the HPG axis can cause amenorrhea, a condition that can lead to the loss of the menstrual cycle and negatively affect bone health, making bones more prone to injury. Additionally, other side effects may include depression, anxiety, and bipolar-like symptoms. While studies have shown the benefits of four to six-hour time-restricted eating, Dr. Panda suggests that eight to ten hours may be the ideal spot to begin with, and 12 hours of feeding and fasting may be appropriate for individuals engaging in physical activity or sports.

10)   Dr. Satchin discusses a study he conducted on nutrition quality and time-restricted eating to see if there was a correlation between the two. Participants were asked to eat within 12 hours and improve their nutrition quality, which resulted in a modest weight loss. Those who followed the time-restricted eating did not change their nutritional quality or habits but still achieved modest weight loss. Dr. Panda suggests combining nutritional advice with time restriction for better results, and reducing the time to 10 hours in a future study. The benefits of time-restricted eating when combined with improved nutrition quality and exercise are examined, along with a study that found a greater weight loss was achieved with a low carbohydrate and caloric restriction.

11)   Dr. Satchin Panda discusses the importance of the timing of one's diet, in addition to the quality and quantity of food. He notes that nearly 40% of people who maintain healthy body weight are very aware of how much and what quality of food they are eating. Dr. Panda also explains that starting and stopping eating at more or less the same time each day, even if caloric restriction is not the main focus, has additional benefits, such as better sleep, more predictable shifts in alertness and sleepiness, and improved gut health. He mentions that those who have acid reflux or heartburn could benefit from not having caffeine in the morning on an empty stomach.

12)   Dr. Satchin discusses the potential risks associated with caffeine consumption in the morning for individuals with anxiety and acid reflux. However, he also notes that the history of human activity reveals the cultural significance of evening activities such assocializing around a communal fire. He explains that coffee consumption started as an evening activity in Istanbul during the 16th century and thus suggests that individuals should not necessarily avoid caffeine in the morning. Instead, he highlights the importance of understanding the cultural and historical context of our behaviors and how they relate to our circadian rhythms.

13)   Dr. Satchin details the history of coffee in Turkey and its connection to the development of breakfast. Coffee was introduced bythe Sufi branch of Islam to stay awake during evening singing and dancing sessions. It was also consumed in the morning to stay awake for the first prayer. However, the strong coffee caused heartburn and acid reflux, and people started eating something with coffee, which led to the development of breakfast. Therefore, breakfast became a buffer against the gastric distress caused by caffeine at least in the Turkish culture. The conversation also touches on delaying caffeine intake for a few hours after waking up to allow natural waking up signals to occur.

14)   Dr. Satchin and Andrew discuss the idea of genetic programming and our internal clocks. They suggest that while some people may be genetically predisposed to a specific schedule, this idea may need revisiting. The conversation also touches on how morning discussions are mostly about work,while evening activities are a time for self-expression and entertainment. As such, the concept of "me time" during the evening hours is important for individuals to truly express who they are and entertain themselves. They suggest that social media time should be restricted to a small portion of the evening as people should also interact socially within a room or connect with their loved ones.

15)  Dr. Satchin discusses the impact of light sensitivity on our circadian rhythms and how it affects our sleep patterns. While some people are more resistant to light and can go to bed early, others are more sensitive and can be easily woken up. Dr. Panda explains that people who are sensitive to light may benefit from using a red night light, which reduces the cortisol-releasing properties of light at night. Additionally, he delves into the idea of whether every hour of sleep before midnight is more valuable and discusses how avoiding bright light in the evening and preparing our bodies for sleep is essential in maintaining a healthy circadian rhythm.

16)   Satchin Panda discusses the negative impact of shift work on sleep and overall health. He highlights the definition of shift work, which is when an individual stays awake for two or more hours during their habitual sleep time. Dr. Panda also shares insights from a recent study on firefighters and time-restricted feeding. He explains how shift work disrupts an individual's physiology, metabolism, behavior, and brain function. It is generally accepted that one in five working adults is a card-carrying shift worker, including those who work in nursing, medicine, firefighting, truck driving, and the service industry.

17)  Dr. Satchin discusses the prevalence of shift work and the burden of health problems borne by shift workers. He notes that around 50% of the adult population at any given time is likely experiencing the lifestyle of a shift worker, which includes college students, new parents, and those in delivery and transportation industries. Additionally, shift workers experience higher rates of age-related diseases, such as high blood pressure,high cholesterol, and diabetes, but are often excluded from clinical trials due to their disrupted sleep schedules. Dr. Panda highlights how difficult it is for shift workers to make lifestyle changes like time-restricted eating or exercise because of their work schedules and exhaustion. He also cites a study that found just 100 lux of dim light present in a sleeping environment can disrupt blood glucose levels.

18)   Satchin discusses the importance of timing when it comes to being active and eating for adults who work a day job. He suggests that feeding mostly during the early part of the day and being active during this time could improve overall health and may help to avoid issues related to disrupted sleep. A recent study carried out by Dr. Panda and Dr. Pam Taub revealed shocking results, which found that over 70% of US firefighters suffer from heart attacks and strokes caused by their work schedules. The study highlights the need for further research to improve the health of shiftworkers, which currently lacks representation with less than 50 clinical trials carried out to date.

19)   Dr. Satchin discusses a clinical trial conducted on firefighters to test their ability to follow a 10-hour time-restricted eating schedule. The firefighters were chosen because of the metabolic stress of their work, and the trial aimed to determine if following the schedule could improve their health in the long-term. The trial found that the firefighters were able to follow the schedule, and it became clear that they were a very tight-knit community that wanted their culture to be understood. Two researchers even lived the life of firefighters for a day to gain a better understanding of their culture. The trial assigned 155 fighters and found that the Mediterranean diet was deemed safe and beneficial for them.

20)   Dr. Satchin Panda discusses a study on firefighters that tested the effects of time-restricted eating. Despite their irregular schedules, the firefighters were able to consistently stick to a 10-hour eating window and saw improvements in their health parameters such as blood pressure and blood glucose management. Additionally, the study found that time-restricted eating improved low-density lipoprotein particle size and number, reducing the risk of atherosclerosis. The results suggest that time-restricted eating can benefit shift workers who may have difficulty regulating their blood sugar due to their work schedule. Overall, consistent meal scheduling is important in maintaining health, similar to the importance of consistent sleep.

21)   Dr. Satchin explains how time-restricted eating can lead to changes in the gut microbiome of mice, resulting in the excretion of some calories and an increase in brown fat activity. He also discusses the challenges of obtaining grant funding for ground-breaking scientific research and the importance of philanthropic support in advancing critical research. Dr.Panda and his team developed an app called MyCircadianClock, which allows users to easily track their eating patterns by taking pictures of their food, and they conducted a three-week study with over 150 participants to analyze the impact of time-restricted eating on metabolism.

22)   Dr. Satchin discusses the results of his study on people's food intake habits. He reveals that the median number of times people eat in a day is seven, with some individuals eating up to 12 times a day. Furthermore, he found that nearly 50% of adults eat for 14 hours and 45 minutes per day, which is the window when their body is expecting food.Additionally, only 10% of adults eat within 12 hours or in the conventional three meals a day pattern, which suggests that snacking has become more frequent throughout the day. As a result, Panda asserts that many people have enough head space to reduce their eating window and eat within 12 hours.

23)   Dr. Satchin discusses the importance of getting enough sleep, especially amongst high school students who are often sleep-deprived due to their use of devices and late-night school assignment submissions. He emphasizes the need for incentivizing people to wake up earlier, sleep earlier, and eat within an 8 to 12 hour window, as research has shown that intermittent fasting can improve health and cognition. Dr. Panda notes that children should eat their last meal one to two hours before bedtime and should not be fed immediately after waking up, and that meal timing and structure are still new fields that require more research.

24)   Satchin discusses the difficulty of sticking to a true ketogenic diet with less than 10% calories from carbohydrates and the potential impact on islet cells in the pancreas that produce insulin. The conversation then turns to the plasticity of the liver and how it reacts to lifestyle changes, as well as the use of drug-mimicking fasting states to reduce mTOR activation and improve health. Dr. Panda also highlights how researchers are studying mice during time and calorie restrictions to investigate the role of fasting in longevity.

25)   Dr. Satchin discusses the potential benefits of metformin and rapamycin, which mimic the fasting state, on health and longevity, as seen in studies on mice. He mentions a recent study that found metformin's ability to reduce glucose fluctuates depending on what time of day it is taken, suggesting different timing of administration may impact its effects. Dr. Panda also shares personal experiences with berberine, cautioning that it can cause hypoglycemia if taken without carbohydrates and emphasizes the importance of paying attention to circadian effects when administering drugs.

26)   Dr. Satchin, explains how metabolism follows a circadian rhythm to align with our natural habits. He notes that many metabolic regulators must have a circadian rhythm, including everything from macronutrient metabolism to protein and carbohydrate metabolism. The conversation also covers the relevancy of shift work and the influence of light and activity on our habits.

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