The Science of Hunger & Medications to Combat Obesity | Dr. Zachary Knight

In this episode, my guest is Dr. Zachary Knight, Ph.D., a professor of physiology at the University of California, San Francisco (UCSF), and Howard Hughes Medical Institute (HHMI) investigator. We discuss how the brain controls our sense of hunger, satiety, and thirst. He explains how dopamine levels impact our cravings and eating behavior (amount, food choices, etc) and how we develop and can change our food preferences and adjust how much we need to eat to feel satisfied. We discuss factors that have led to the recent rise in obesity, such as interactions between our genes and the environment and the role of processed foods and food combinations. We also discuss the new class of medications developed for the treatment of obesity and diabetes, including the GLP-1 agonists semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro). We discuss how these medications work to promote weight loss, the source of their side effects, and the newer compounds soon to overcome some of those side effects, such as muscle loss. Dr. Knight provides an exceptionally clear explanation for our sense of hunger, thirst, and food cravings that translates to practical knowledge to help listeners better understand their relationship to food, food choices, and meal size to improve their diet and overall health. Access the full show notes, including referenced articles, books, people mentioned, and additional resources: https://www.hubermanlab.com/episode/dr-zachary-knight-the-science-of-hunger-medications-to-combat-obesity Thank you to our sponsors AG1: https://drinkag1.com/huberman BetterHelp: https://betterhelp.com/huberman Eight Sleep: https://eightsleep.com/huberman Waking Up: https://wakingup.com/huberman LMNT: https://drinklmnt.com/huberman Huberman Lab Social & Website Instagram: https://www.instagram.com/hubermanlab Threads: https://www.threads.net/@hubermanlab Twitter: https://twitter.com/hubermanlab Facebook: https://www.facebook.com/hubermanlab TikTok: https://www.tiktok.com/@hubermanlab LinkedIn: https://www.linkedin.com/in/andrew-huberman Website: https://www.hubermanlab.com Newsletter: https://www.hubermanlab.com/newsletter Dr. Zachary Knight UCSF academic profile: https://profiles.ucsf.edu/zachary.knight HHMI profile: https://www.hhmi.org/scientists/zachary-knight Publications: https://knightlab.ucsf.edu/publications Lab website: https://knightlab.ucsf.edu X: https://x.com/zaknight Instagram: https://www.instagram.com/zknightsf LinkedIn: https://www.linkedin.com/in/zachary-knight-29a37977 Timestamps 00:00:00 Dr. Zachary Knight 00:02:38 Sponsors: BetterHelp, Helix Sleep & Waking Up 00:07:07 Hunger & Timescales 00:11:28 Body Fat, Leptin, Hunger 00:17:51 Leptin Resistance & Obesity 00:20:52 Hunger, Food Foraging & Feeding Behaviors, AgRP Neurons 00:30:26 Sponsor: AG1 00:32:15 Body Weight & Obesity, Genes & POMC Neurons 00:39:54 Obesity, Genetics & Environmental Factors 00:46:05 Whole Foods, Ultra-Processed Foods & Palatability 00:49:32 Increasing Whole Food Consumption, Sensory Specific Satiety & Learning 00:58:55 Calories vs. Macronutrients, Protein & Salt 01:02:23 Sponsor: LMNT 01:03:58 Challenges of Weight Loss: Hunger & Energy Expenditure 01:09:50 GLP-1 Drug Development, Semaglutide, Ozempic, Wegovy 01:19:03 GLP-1 Drugs: Muscle Loss, Appetite Reduction, Nausea 01:23:24 Pharmacologic & Physiologic Effects; GLP-1 Drugs, Additional Positive Effects 01:30:14 GLP-1-Plus Development, Tirzepatide, Mounjaro, AMG 133 01:34:49 Alpha-MSH & Pharmacology 01:40:41 Dopamine, Eating & Context 01:46:01 Dopamine & Learning, Water Content & Food 01:53:23 Salt, Water & Thirst 02:03:27 Hunger vs. Thirst 02:05:46 Dieting, Nutrition & Mindset 02:09:39 Tools: Improving Diet & Limiting Food Intake 02:14:15 Anti-Obesity Drug Development 02:17:03 Zero-Cost Support, Spotify & Apple Follow & Reviews, YouTube Feedback, Social Media, Neural Network Newsletter #HubermanLab #Health #Obesity Title Card Photo Credit: Mike Blabac - https://www.blabacphoto.com Disclaimer: https://www.hubermanlab.com/disclaimer

Andrew HubermanhostDr. Zachary Knightguest

Jun 17, 20242h 18mWatch on YouTube ↗

EPISODE INFO

Released: June 17, 2024
Duration: 2h 18m
Channel: Huberman Lab
Watch on YouTube: ▶ Open ↗

EPISODE DESCRIPTION

In this episode, my guest is Dr. Zachary Knight, Ph.D., a professor of physiology at the University of California, San Francisco (UCSF), and Howard Hughes Medical Institute (HHMI) investigator. We discuss how the brain controls our sense of hunger, satiety, and thirst. He explains how dopamine levels impact our cravings and eating behavior (amount, food choices, etc) and how we develop and can change our food preferences and adjust how much we need to eat to feel satisfied. We discuss factors that have led to the recent rise in obesity, such as interactions between our genes and the environment and the role of processed foods and food combinations. We also discuss the new class of medications developed for the treatment of obesity and diabetes, including the GLP-1 agonists semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro). We discuss how these medications work to promote weight loss, the source of their side effects, and the newer compounds soon to overcome some of those side effects, such as muscle loss. Dr. Knight provides an exceptionally clear explanation for our sense of hunger, thirst, and food cravings that translates to practical knowledge to help listeners better understand their relationship to food, food choices, and meal size to improve their diet and overall health. Access the full show notes, including referenced articles, books, people mentioned, and additional resources: https://www.hubermanlab.com/episode/dr-zachary-knight-the-science-of-hunger-medications-to-combat-obesity Thank you to our sponsors AG1: https://drinkag1.com/huberman BetterHelp: https://betterhelp.com/huberman Eight Sleep: https://eightsleep.com/huberman Waking Up: https://wakingup.com/huberman LMNT: https://drinklmnt.com/huberman Huberman Lab Social & Website Instagram: https://www.instagram.com/hubermanlab Threads: https://www.threads.net/@hubermanlab Twitter: https://twitter.com/hubermanlab Facebook: https://www.facebook.com/hubermanlab TikTok: https://www.tiktok.com/@hubermanlab LinkedIn: https://www.linkedin.com/in/andrew-huberman Website: https://www.hubermanlab.com Newsletter: https://www.hubermanlab.com/newsletter Dr. Zachary Knight UCSF academic profile: https://profiles.ucsf.edu/zachary.knight HHMI profile: https://www.hhmi.org/scientists/zachary-knight Publications: https://knightlab.ucsf.edu/publications Lab website: https://knightlab.ucsf.edu X: https://x.com/zaknight Instagram: https://www.instagram.com/zknightsf LinkedIn: https://www.linkedin.com/in/zachary-knight-29a37977 Timestamps 00:00:00 Dr. Zachary Knight 00:02:38 Sponsors: BetterHelp, Helix Sleep & Waking Up 00:07:07 Hunger & Timescales 00:11:28 Body Fat, Leptin, Hunger 00:17:51 Leptin Resistance & Obesity 00:20:52 Hunger, Food Foraging & Feeding Behaviors, AgRP Neurons 00:30:26 Sponsor: AG1 00:32:15 Body Weight & Obesity, Genes & POMC Neurons 00:39:54 Obesity, Genetics & Environmental Factors 00:46:05 Whole Foods, Ultra-Processed Foods & Palatability 00:49:32 Increasing Whole Food Consumption, Sensory Specific Satiety & Learning 00:58:55 Calories vs. Macronutrients, Protein & Salt 01:02:23 Sponsor: LMNT 01:03:58 Challenges of Weight Loss: Hunger & Energy Expenditure 01:09:50 GLP-1 Drug Development, Semaglutide, Ozempic, Wegovy 01:19:03 GLP-1 Drugs: Muscle Loss, Appetite Reduction, Nausea 01:23:24 Pharmacologic & Physiologic Effects; GLP-1 Drugs, Additional Positive Effects 01:30:14 GLP-1-Plus Development, Tirzepatide, Mounjaro, AMG 133 01:34:49 Alpha-MSH & Pharmacology 01:40:41 Dopamine, Eating & Context 01:46:01 Dopamine & Learning, Water Content & Food 01:53:23 Salt, Water & Thirst 02:03:27 Hunger vs. Thirst 02:05:46 Dieting, Nutrition & Mindset 02:09:39 Tools: Improving Diet & Limiting Food Intake 02:14:15 Anti-Obesity Drug Development 02:17:03 Zero-Cost Support, Spotify & Apple Follow & Reviews, YouTube Feedback, Social Media, Neural Network Newsletter #HubermanLab #Health #Obesity Title Card Photo Credit: Mike Blabac - https://www.blabacphoto.com Disclaimer: https://www.hubermanlab.com/disclaimer

SPEAKERS

Andrew Huberman
host
Dr. Zachary Knight
guest

EPISODE SUMMARY

In this episode of Huberman Lab, featuring Andrew Huberman and Dr. Zachary Knight, The Science of Hunger & Medications to Combat Obesity | Dr. Zachary Knight explores how Your Brain Predicts Hunger, Thirst, and Weight-Loss Drug Effects Andrew Huberman interviews UCSF physiologist Dr. Zachary Knight about the neural circuits that control hunger, thirst, and body-weight regulation, and how those insights underlie modern obesity drugs. Knight explains the dual-system model of feeding: slow hypothalamic circuits that track body fat over weeks to years, and fast brainstem circuits that control meal size on the scale of minutes. They discuss leptin, AgRP and POMC neurons, dopamine’s real role in motivation and learning (not pleasure per se), and how the brain constantly predicts future nutrient and fluid states to guide behavior. The conversation culminates in a detailed, mechanistic look at GLP‑1 agonists like Ozempic and tirzepatide, why they work when earlier approaches failed, and what next-generation obesity pharmacology will likely look like.

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