April 19, 2021 • 1hr 39min

How Hormones Control Hunger, Eating & Satiety

Huberman Lab

In this episode, Dr. Andrew Huberman discusses how hormones from the gut, liver, pancreas and brain control appetite and hunger. He explains the specific neural circuits and hormones involved, and provides actionable tools to regulate these systems. The episode covers the biology behind hunger and satiety, as well as practical strategies for managing blood sugar, meal timing, and overall metabolic health.

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Key Takeaways

Hormones and neural circuits work together to control hunger, appetite, and satiety. Key players include ghrelin, melanocyte stimulating hormone (MSH), cholecystokinin (CCK), insulin, and glucagon.
Getting sunlight exposure, especially in the morning, can help regulate appetite by stimulating release of MSH which suppresses hunger.
Meal timing influences hunger more than the other way around. Ghrelin secretion adapts to regular meal schedules, so shifting meal times gradually by 45 minutes per day can help adjust eating patterns.
The order you eat foods in a meal matters for blood sugar regulation. Eating fibrous vegetables first, then protein, then carbs can help blunt glucose spikes.
Exercise, especially zone 2 cardio and resistance training, improves insulin sensitivity and glucose management.
Highly processed foods with emulsifiers disrupt gut signaling and promote overeating. Focusing on whole, unprocessed foods is beneficial for appetite regulation.
Supplements like berberine and prescription drugs like metformin can powerfully lower blood glucose, but should be used cautiously under medical supervision.
Yerba mate tea can help suppress appetite by increasing glucagon-like peptide 1 (GLP-1) and leptin levels.

Introduction

In this episode, Dr. Andrew Huberman discusses how hormones from the gut, liver, pancreas and brain control appetite and hunger. He explains the specific neural circuits and hormones involved, and provides actionable tools to regulate these systems. The episode covers the biology behind hunger and satiety, as well as practical strategies for managing blood sugar, meal timing, and overall metabolic health.

Topics Discussed

Neural Control of Hunger (6:59)

The hypothalamus, particularly the ventromedial hypothalamus, contains key neurons that regulate hunger and feeding behaviors. Two important populations are:

POMC neurons - Release melanocyte stimulating hormone (MSH) which reduces appetite
AgRP neurons - Stimulate eating and increase when starved

The insular cortex also plays a role in processing sensory information from the mouth related to food texture and chewing.

Hormonal Control of Hunger (11:05)

Key hormones that regulate hunger and satiety include:

Melanocyte stimulating hormone (MSH) - Released from the pituitary, suppresses appetite
Ghrelin - Released from the GI tract, increases hunger and food anticipatory behaviors
Cholecystokinin (CCK) - Released from the gut, reduces appetite
Insulin - Lowers blood glucose and promotes energy storage
Glucagon - Raises blood glucose by mobilizing energy stores

Sunlight and Appetite Regulation (16:57)

Ultraviolet light exposure to the eyes stimulates MSH release, which can help suppress appetite. This is one reason why getting morning sunlight exposure is beneficial for metabolic health. It may also explain reduced appetite in spring/summer months.

Ghrelin and Meal Timing (22:30)

Ghrelin secretion adapts to regular meal schedules, making you hungry at predictable times. To shift meal timing:

Gradually adjust meal times by about 45 minutes per day
This allows the ghrelin system to adapt without major discomfort
Can help transition to intermittent fasting or different eating schedules

CCK and Nutrient Sensing (33:02)

CCK is released from the gut in response to fatty acids and amino acids, signaling satiety. Key points:

Omega-3 fatty acids and conjugated linoleic acid (CLA) stimulate CCK release
The amino acid glutamine potently triggers CCK
We eat until threshold levels of these nutrients are reached
Glutamine supplementation may help reduce sugar cravings

Processed Foods and Emulsifiers (43:42)

Highly processed foods often contain emulsifiers that disrupt the gut lining and nutrient sensing:

Emulsifiers strip away the mucosal lining of the gut
This impairs the ability to detect nutrients and trigger satiety signals
Can lead to overeating and disrupted appetite regulation
Focusing on whole, unprocessed foods is beneficial

Blood Glucose Regulation (52:36)

Maintaining stable blood glucose is important for overall health. Key concepts:

Healthy fasting glucose range is 70-100 mg/dL
Insulin lowers blood glucose, glucagon raises it
The order you eat foods impacts glucose response
Eating fibrous vegetables first, then protein, then carbs can blunt glucose spikes

Exercise and Glucose Management (1:02:40)

Exercise has powerful effects on glucose regulation:

Zone 2 cardio (30-60 min, 3-4x/week) improves insulin sensitivity
High intensity interval training and resistance training promote glucose uptake into muscles
Even light movement after meals can help blunt glucose spikes

Cholesterol and Hormone Production (1:10:28)

Cholesterol is important for hormone production:

HDL cholesterol helps deliver fats to organs that produce hormones
This includes the liver, ovaries, testes, and adrenal glands
Managing blood glucose also impacts cholesterol ratios

Supplements and Medications for Glucose Control (1:15:00)

Several supplements and medications can impact blood glucose:

Metformin - Prescription drug that potently lowers blood glucose
Berberine - Supplement with similar effects to metformin
Chromium, magnesium, zinc - May have modest glucose-lowering effects
Apple cider vinegar - Acidity can blunt glucose spikes slightly

Dr. Huberman cautions to use these carefully and consult a physician, especially berberine and metformin which have powerful effects.

Ketogenic Diets (1:26:40)

Ketogenic diets can effectively lower blood glucose, but may impact thyroid function if followed long-term. Dr. Huberman plans to cover ketosis in more depth in a future episode.

Yerba Mate and GLP-1 (1:31:08)

Yerba mate tea has some unique properties:

Increases glucagon-like peptide 1 (GLP-1) which suppresses appetite
Contains caffeine and electrolytes
Can help extend fasting windows

Conclusion

This episode provided a comprehensive overview of the hormonal and neural systems regulating hunger, appetite, and metabolism. Dr. Huberman covered actionable tools ranging from light exposure and meal timing to exercise and specific supplements. Understanding these mechanisms can help inform strategies for managing blood sugar, body composition, and overall metabolic health. Future episodes will dive deeper into related topics like thyroid function and ketogenic diets.