Episode
Effects of Fasting & Time Restricted Eating on Fat Loss & Health
2:25:01
Published: Mon Oct 11 2021
Description
This episode I discuss the science and practice of fasting also called time-restricted feeding. I review the data on how limiting food intake to specific portions of every 24-hour cycle (or fasting longer) impacts weight loss, fat loss specifically, liver health, mental focus, muscle, longevity and more. I explain how "fasted" is contextual, and relates to blood glucose levels and their downstream effects, and how the depth of fasting can be adjusted with behaviors such as different types of exercise, or with glucose disposal agents. I also discuss the optimal fasting protocol: and both the absolute (non-negotiable) and variable (contextual) features of a fasting/time-restricted-feeding protocol that will allow you to get the most benefits. I also discuss what does and does not break a fast, the effects of fasting on hormones like testosterone and cortisol and on fertility. I also review how different feeding windows of 8 or 10 or 4 hours differentially impact the effects of fasting, and why the classic 8 hour feeding window came to be but also might be ideal. I discuss mechanisms and offer tools to discern the optimal fasting duration and timing for you. For the full show notes, visit hubermanlab.com. Thank you to our sponsors AG1 (Athletic Greens): https://athleticgreens.com/huberman LMNT: https://drinklmnt.com/huberman Thesis: https://takethesis.com/huberman Supplements from Momentous https://www.livemomentous.com/huberman Timestamps (00:00:00) Introduction, Blood Glucose & Mortality, Mice Vs. Humans (00:06:18) Sponsors: AG1, LMNT, Thesis, Momentous (00:09:42) Neuroplasticity Protocols & Online Lecture (00:11:20) Feeding, Fasting, Performance (00:13:50) Calories-In, Calories-Out (CICO); Perfect Diets (00:19:48) Feeding-Induced Health Conditions (00:25:33) Time Restricted Eating: When We Eat Is Vital (00:29:45) The Eight Hour Feeding Window (00:31:26) Feeding Deep Into the Night Is Bad (In Humans) (00:36:33) Liver Health (00:39:45) Time Restricted Feeding Protocol: Rules (00:41:35) When to Start & Stop Eating (00:45:38) Gastric Clearance, Linking Fasting to Sleep (00:52:35) Effects of Specific Categories of Food (00:55:40) Precision In Fasting: Protocol Build (00:59:30) 4-6 Hour Feeding Windows (01:03:08) Protein Consumption & Timing for Muscle (01:08:13) How to Shift Your Eating Window (01:13:20) Glucose Clearing, Exercise & Compounds (01:22:37) Blood Glucose: Monitoring, mTOR & Related Pathways (01:27:40) Gut Health: Fasting, Clock Genes and Microbiota (01:29:15) Non-Alcoholic Fatty Liver (01:32:00) Effects of Fasting on Hormones: Testosterone, Cortisol (01:38:40) Fertility (01:41:50) 8-Hour Feeding Window: Weight Loss Without Calorie Counting (01:43:20) Eating Every-Other-Day (01:45:29) Adherence (01:47:15) Mental Focus & Clarity (01:49:12) Enhancing Weight Loss from Body Fat: Hepatic Lipase (01:53:15) What Breaks a Fast? Rules & Context (01:58:50) Artificial Sweeteners, Plant-Based Sweeteners (02:01:42) Glucose Clearing II, Cinnamon, Acidity, Salt (02:06:42) My Circadian Clock, Zero-App (02:08:20) Odd (But Common) Questions (02:09:23) Effects of Sauna & Dehydration on Blood Glucose (02:11:12) The Ideal Fasting Protocol (02:24:00) More Resources, Ways to Support Us, Supplements Title Card Photo Credit: Mike Blabac Disclaimer
Chapters
Ben Greenfield discusses the various ways in which intermittent fasting impacts weight loss, muscle maintenance, organ health, the genome, cognition, mood, and lifespan, and shares tools that make it possible to follow the feeding schedule without strict regimentation.
00:00 - 10:46 (10:46)
Summary
Ben Greenfield discusses the various ways in which intermittent fasting impacts weight loss, muscle maintenance, organ health, the genome, cognition, mood, and lifespan, and shares tools that make it possible to follow the feeding schedule without strict regimentation. He distinguishes the effect of fasting schedule on blood glucose levels in mice versus humans and explains how resting blood glucose levels increase with age.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
This podcast discusses time-restricted feeding, also known as fasting, and its health benefits.
10:46 - 25:18 (14:32)
Summary
This podcast discusses time-restricted feeding, also known as fasting, and its health benefits. It clarifies that fasting and time-restricted feeding have different effects on the body and establishes the importance of understanding the context in which a given diet regimen is taking place.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
A study conducted on mice revealed that restricting their feeding window to eight hours even on a high-fat diet could result in weight maintenance or loss.
25:18 - 31:28 (06:09)
Summary
A study conducted on mice revealed that restricting their feeding window to eight hours even on a high-fat diet could result in weight maintenance or loss. Additionally, the mice that followed this feeding pattern showed improvements in their health markers.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
This study found that restricting food intake to a specific time window within the most active phase of the 24-hour cycle can benefit lean body mass, fat loss, and overall health.
31:28 - 44:46 (13:18)
Summary
This study found that restricting food intake to a specific time window within the most active phase of the 24-hour cycle can benefit lean body mass, fat loss, and overall health. It can also regulate gene systems and support a healthier circadian rhythm.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
The timing of when we eat and sleep is interconnected.
44:46 - 50:07 (05:21)
Summary
The timing of when we eat and sleep is interconnected. People who push their feeding window late into the night would be missing out on sleep-related fasting which can impact their health.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
This podcast explains that starting to eat each day around 10 am or noon and allowing a feeding window until 6 or 8 pm is the best schedule for intermittent fasting without disrupting social rhythms, and how sleep-related fasting can be beneficial.
50:07 - 56:40 (06:33)
Summary
This podcast explains that starting to eat each day around 10 am or noon and allowing a feeding window until 6 or 8 pm is the best schedule for intermittent fasting without disrupting social rhythms, and how sleep-related fasting can be beneficial.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
This podcast discusses the effects of feeding windows on hormone health, hormone production, fertility and performance in work and in sports, highlighting that a strict or semi-strict feeding window is important for optimal health.
56:40 - 1:10:09 (13:28)
Summary
This podcast discusses the effects of feeding windows on hormone health, hormone production, fertility and performance in work and in sports, highlighting that a strict or semi-strict feeding window is important for optimal health. It also explores the benefits of ingesting protein early in the day for hypertrophy using clock-regulated protein synthesis mechanisms.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
High-intensity interval training performed later in the day can help lower blood glucose levels and prepare the body for a fasted state before bedtime.
1:10:09 - 1:20:13 (10:04)
Summary
High-intensity interval training performed later in the day can help lower blood glucose levels and prepare the body for a fasted state before bedtime. Eating late in the day and close to bedtime can impact clock genes and subtract sleep-related fasting, making it important to perform HIIT in the evening for metabolic health.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
The fed state promotes cellular growth while the fasted state promotes cellular repair and clearance.
1:20:13 - 1:26:55 (06:41)
Summary
The fed state promotes cellular growth while the fasted state promotes cellular repair and clearance. Glucose disposal agents such as metformin and berberine lead to significant reductions in blood glucose, caution must be taken to avoid clearing out already low blood glucose levels.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
Brown fat is a healthy fat that we have between our two scapulae and in our upper neck.
1:26:55 - 1:36:05 (09:10)
Summary
Brown fat is a healthy fat that we have between our two scapulae and in our upper neck.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
A gradual transition into time restricted feeding, allowing hormone systems of the body to adjust, is important to prevent overwhelming hunger and irritability, and not to disrupt the hormone system.
1:36:05 - 1:43:03 (06:57)
Summary
A gradual transition into time restricted feeding, allowing hormone systems of the body to adjust, is important to prevent overwhelming hunger and irritability, and not to disrupt the hormone system. It's up to the individual whether a time restricted feeding window would work for them and for how long it should be.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
Time-restricted feeding for 60 days or more can shift your system towards more fat loss, while mental clarity and focus are additional benefits that draw people in.
1:43:03 - 1:53:26 (10:22)
Summary
Time-restricted feeding for 60 days or more can shift your system towards more fat loss, while mental clarity and focus are additional benefits that draw people in. The eight-hour feeding window is currently the most tested and should be the orientation for those considering time-restricted feeding.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
A discussion regarding the effects of non-sugar sweeteners like Stevia on the blood glucose levels when consumed in moderation versus when consumed in excess.
1:53:26 - 2:01:59 (08:33)
Summary
A discussion regarding the effects of non-sugar sweeteners like Stevia on the blood glucose levels when consumed in moderation versus when consumed in excess. The adverse effects on the gut microbiome of some artificial sweeteners are also pointed out.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
When feeling shaky and lightheaded, many people assume they need food or sugar, but adding a pinch of salt to water can actually remedy the issue by regulating salt levels in the blood and body.
2:01:59 - 2:11:11 (09:12)
Summary
When feeling shaky and lightheaded, many people assume they need food or sugar, but adding a pinch of salt to water can actually remedy the issue by regulating salt levels in the blood and body. Additionally, some people find that by adding lemon juice to the salt water, it can help lower glucose levels and improve overall feelings of well-being.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
This transcript discusses the feasibility of one meal per day eating approach and its compatibility with various lifestyles.
2:11:11 - 2:23:25 (12:13)
Summary
This transcript discusses the feasibility of one meal per day eating approach and its compatibility with various lifestyles. It suggests that although some people may be able to adhere to it, an eight-hour feeding window, or a four to six hour feeding window, could be a more practical option for most individuals, with a potentially similar level of benefits.
EpisodeEffects of Fasting & Time Restricted Eating on Fat Loss & Health
PodcastHuberman Lab
Evaluating your own system is the most important thing in finding an ideal nutrition schedule that works for you.
2:23:25 - 2:25:35 (02:10)
Summary
Evaluating your own system is the most important thing in finding an ideal nutrition schedule that works for you. A safe experiment on your system can lead to understanding how different foods and fasting works for you.