March 13, 2023 • 2hr 44min

Dr. Satchin Panda: Intermittent Fasting to Improve Health, Cognition & Longevity

Huberman Lab

In this episode, Dr. Andrew Huberman interviews Dr. Satchin Panda, a professor and director of the Regulatory Biology Laboratory at the Salk Institute. Dr. Panda is a leading expert on circadian rhythms and pioneered research on time-restricted eating (TRE). They discuss how TRE and other circadian-aligned behaviors can impact metabolism, longevity, and overall health.

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Key Takeaways

Time-restricted eating (TRE) involves confining all calorie intake to a consistent 8-12 hour window each day
TRE can provide health benefits even without calorie restriction, including improved metabolic health and potentially increased lifespan
Consistency in meal timing is important - eating at the same times each day allows the body to anticipate and prepare for food intake
About 50% of adults eat over a 15+ hour window each day due to frequent snacking and late night eating
Shift work and staying up late with artificial light exposure can disrupt circadian rhythms and metabolism
Children and teenagers need 9-10 hours of sleep and should eat within a 12 hour window
Firefighters practicing 10-hour TRE showed improvements in blood pressure and blood sugar control
Longer fasts (24+ hours) may have benefits for physical and mental health but more research is needed
Aligning eating, sleeping, light exposure and activity patterns with circadian rhythms is ideal for health

Introduction

In this episode, Dr. Andrew Huberman interviews Dr. Satchin Panda, a professor and director of the Regulatory Biology Laboratory at the Salk Institute. Dr. Panda is a leading expert on circadian rhythms and pioneered research on time-restricted eating (TRE). They discuss how TRE and other circadian-aligned behaviors can impact metabolism, longevity, and overall health.

Topics Discussed

Defining Time-Restricted Eating (6:04)

Dr. Panda explains that time-restricted eating involves confining all calorie intake to a consistent 8-12 hour window each day. This is distinct from other forms of intermittent fasting that involve more severe calorie restriction. The key aspects of TRE are:

Eating within a consistent daily window (e.g. 8am-6pm)
Fasting for 12-16 hours between the last meal of the day and first meal the next day
No calorie restriction required during the eating window

Dr. Panda notes that TRE leverages the body's circadian rhythms and can provide health benefits even without reducing total calorie intake.

Circadian Rhythms and Meal Timing (14:58)

The discussion explores how meal timing impacts circadian rhythms throughout the body:

Food is a powerful circadian signal that can shift the timing of clocks in organs like the liver
The body anticipates and prepares for food intake at consistent times
Eating at irregular times can disrupt this anticipatory activity
Consistent meal timing allows for optimal digestion and nutrient absorption

Dr. Panda emphasizes that "When you change our feeding time, we can change, we can tune our liver clock."

Benefits of Time-Restricted Eating (34:04)

The potential benefits of TRE discussed include:

Improved metabolic health markers like blood sugar control
Reduced risk of chronic diseases
Potentially increased lifespan (based on animal studies)
Better alignment of feeding/fasting with circadian rhythms
Improved sleep quality

Dr. Panda notes that in mice, TRE increased lifespan by 10-35% depending on the specific protocol used.

Gender Differences and Relative Energy Deficiency in Sports (47:20)

Important considerations around TRE for different populations:

Women may be more susceptible to hormonal disruptions from severe calorie restriction
Relative Energy Deficiency in Sports (REDS) can occur in athletes who restrict calories too much
REDS can lead to loss of menstrual cycle, bone density issues, and mental health impacts in female athletes
A 12-hour eating window may be more appropriate for very active individuals

Shift Work and Circadian Disruption (1:36:05)

The widespread impacts of shift work and circadian disruption are discussed:

About 20% of working adults are shift workers (nurses, firefighters, etc.)
Up to 50% of adults experience shift work-like disruption from late night habits
Shift workers have higher rates of metabolic diseases and other health issues
Even short-term circadian disruption can impair glucose regulation

Dr. Panda notes: "Almost all age-related disease that we can think of...are disproportionately more prevalent among shift workers."

Firefighter Study on Time-Restricted Eating (1:50:59)

Dr. Panda describes a study his lab conducted on firefighters practicing 10-hour TRE:

150 firefighters participated, half did TRE and half followed standard diet advice
TRE group showed improvements in blood pressure and blood sugar control
Most were able to stick to TRE at least 5 days per week
TRE group also reduced alcohol intake

This study demonstrated TRE can be feasible and beneficial even for shift workers with irregular schedules.

Recommendations for Time-Restricted Eating (2:09:15)

Key recommendations for implementing TRE:

12-hour eating window is a good starting point for most people
Children and teenagers should eat within a 12-hour window
Very active individuals may do better with a 12-hour vs. 8-10 hour window
Consistency in meal timing from day to day is important
Align eating window with daytime/active hours when possible

Longer Fasts and Other Approaches (2:25:20)

The discussion touches on other fasting approaches:

24+ hour fasts may have benefits but more research is needed
Some clinics use supervised multi-day fasts for various health conditions
"Fat fasting" (very low carb) may have downsides of reduced pancreatic function
Drugs like metformin and rapamycin may mimic some fasting effects

Dr. Panda cautions that the long-term impacts of extended fasting or extreme low-carb diets are not yet well understood.

Conclusion

This wide-ranging discussion highlights the importance of aligning eating patterns, sleep, light exposure, and activity with our circadian rhythms for optimal health. Time-restricted eating offers a simple yet powerful way to improve metabolic health without necessarily changing what or how much we eat. While more research is still needed, especially in humans, the existing evidence suggests TRE could be a valuable tool for preventing chronic diseases and potentially extending lifespan. Dr. Panda emphasizes that a 12-hour eating window is a good starting point for most people to align their eating with circadian rhythms. Overall, paying attention to when we eat may be just as important as what we eat for long-term health.