The Ultimate Human with Gary Brecka - 220. Cortisol, Leptin, and Ghrelin: Why Your Hormones Are Sabotaging Your Health
Episode Date: November 20, 2025Your body is sending you signals every moment of every day, but are you listening? In this episode, I’ll walk you through how these three hormones (cortisol, leptin, and ghrelin) dictate whether you... wake up energised or exhausted, maintain focus or feel scattered, and recover quickly or stay stuck in chronic stress mode. Your hormones respond to your daily choices; make them work for you instead of against you. Join the Ultimate Human VIP community for Gary Brecka's proven wellness protocols! https://bit.ly/4ai0Xwg Thank you to our partners H2TABS: “ULTIMATE10” FOR 10% OFF: https://bit.ly/4hMNdgg BODYHEALTH: “ULTIMATE20” FOR 20% OFF: http://bit.ly/4e5IjsV BAJA GOLD: "ULTIMATE10" FOR 10% OFF: https://bit.ly/3WSBqUa COLD LIFE: THE ULTIMATE HUMAN PLUNGE: https://bit.ly/4eULUKp WHOOP: JOIN AND GET 1 FREE MONTH!: https://bit.ly/3VQ0nzW AION: “ULTIMATE10” FOR 10% OFF: https://bit.ly/4h6KHAD A-GAME: “ULTIMATE15” FOR 15% OFF: http://bit.ly/4kek1ij CARAWAY: “ULTIMATE” FOR 10% OFF: https://bit.ly/3Q1VmkC HEALF: 10% OFF YOUR ORDER: https://bit.ly/41HJg6S RHO NUTRITION: “ULTIMATE15” FOR 15% OFF: https://bit.ly/44fFza0 GOPUFF: GET YOUR FAVORITE SNACK!: https://bit.ly/4obIFDC GENETIC METHYLATION TEST (UK ONLY): https://bit.ly/48QJJrk GENETIC TEST (USA ONLY): https://bit.ly/3Yg1Uk9 Watch the “Ultimate Human Podcast” every Tuesday & Thursday at 9AM EST: YouTube: https://bit.ly/3RPQYX8 Podcasts: https://bit.ly/3RQftU0 Connect with Gary Brecka Instagram: https://bit.ly/3RPpnFs TikTok: https://bit.ly/4coJ8fo X: https://bit.ly/3Opc8tf Facebook: https://bit.ly/464VA1H LinkedIn: https://bit.ly/4hH7Ri2 Website: https://bit.ly/4eLDbdU Merch: https://bit.ly/4aBpOM1 Newsletter: https://bit.ly/47ejrws Ask Gary: https://bit.ly/3PEAJuG Timestamps 00:00 Intro of Show 01:07 Cortisol Definition and Reduction 05:00 What are Leptin and Ghrelin? 06:20 Effects of Consistent Calorie Restriction 07:30 Link to Study on Leptin Receptors: https://bit.ly/49nHUlX 08:30 How to Balance These 3 Hormones The Ultimate Human with Gary Brecka Podcast is for general informational purposes only and does not constitute the practice of medicine, nursing or other professional health care services, including the giving of medical advice, and no doctor/patient relationship is formed. The use of information on this podcast or materials linked from this podcast is at the user’s own risk. The Content of this podcast is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard or delay in obtaining medical advice for any medical condition they may have and should seek the assistance of their health care professionals for any such conditions. Learn more about your ad choices. Visit megaphone.fm/adchoices
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So many things in our current environment from consistent phone notifications to ultra-processed foods
can impact how well we can notice what our body is actually trying to tell us.
We're exploring cortisol, leptin, and grelin today.
I want to break down these complex biochemical concepts because they determine whether you feel energized or exhausted
or whether you maintain healthy weight or you struggle with cravings.
These powerful chemical messengers can either work for you or they can work against you.
Cortisol gets a bad reputation, but acute cortisol spikes are actually.
necessary for survival, leptin and ghrelin. Two hormones that control your appetite and your
energy balance. These work in opposition to each other, creating an interconnected dynamic for
managing food and energy storage. Understanding these three key hormones gives you the keys to
mastering stress resilience and appetite control. If you're unaware of how these systems work,
it could leave you fighting an uphill battle against your own biology. Let's start with...
We're told all the time, listen to our bodies, but what does that actually mean?
Today, we're talking about three hormones that tell us when we're hungry and when we're stressed.
But so many things in our current environment from consistent phone notifications to ultra-processed foods
can impact how well we can notice what our body is actually trying to tell us.
Because these powerful chemical messengers can either work for you or they can work against.
you. It's so important to understand these signals and how we can interpret them. I'm biohacker and
human biologist Gary Brecker and you're listening to the Ultimate Human Podcast where we explore the
cutting edge science behind human performance and longevity. We're exploring cortisol, leptin, and
grelin today. I want to break down these complex biochemical concepts because they determine
whether you feel energized or exhausted or whether you maintain healthy weight or you struggle
with cravings or whether or not you wake soundly or lie awake at night.
night. Understanding these three key hormones gives you the keys to mastering stress resilience
and appetite control. If you're unaware of how these systems work, it could leave you fighting
an uphill battle against your own biology. Let's start with cortisol, known as the stress hormone.
Cortisol gets a bad reputation, but acute cortisol spikes are actually necessary for survival.
The problem, as many of you know, occurs when short-term stress responses become chronic,
constantly elevated. Your cortisol levels naturally follow a daily circadian rhythm. They peak shortly
after you wake up, giving you energy to start your day, and then they gradually decline,
reaching their lowest point at night to allow for restorative sleep. This pattern gets disrupted,
and then your entire hormonal system suffers. Recent research has revealed some new insights
about cortisol management. A systemic review looked at dozens of clinical trials evaluating stress
reduction interventions. Researchers looked at mindfulness practices, mindset shifts, and aerobic exercise
measuring their overall effects on lowering baseline cortisol. The most striking finding was that
stacking more than one of these interventions had the best benefit. Single changes helped,
but combining multiple techniques actually created long-term change. But here's something that might
surprise you. A unique article introduced the concept of nature pills. Scientists found that the calm
feeling you get out in the woods or on the beach isn't something you imagined. You actually
have chemical and biological responses to it. Even brief 20 to 30 minute exposures to green
spaces could significantly decrease cortisol. This happens through activation of your parasympathetic,
the rest and digest system, and dampening of what's called the HPA axis, your body's primary
stress response pathway. A meta-analysis supported these findings, linking increased natural
environment exposure to reduced cortisol levels and improvements in mood and stress resilience.
This establishes nature-based therapies as credible cortisol regulators that anyone can access.
It's a well-known fact that Chinese medicine has actually used forest bathing for centuries
to reduce stress levels. Natural cortisol reduction starts with understanding how your nervous
system works. Deep breathing exercise is something I'm a huge fan of, stimulate the vagus nerve,
promoting autonomic balance that lowers the formation of cortisol. Practicing at least five minutes
of deep breathing several times a day has shown reductions in anxiety and fight or flight arousal.
Mind-body integrative therapies like yoga and Tai Chi can also provide benefits. They combine breath
control, gentle movement, and mindfulness, reinforcing cortisol lowering effects through neuroendocrine
modulation. These practices basically teach your nervous system how to shift from stress mode to
recovery mode. Those nature pills I mentioned earlier, they represent one of the most
accessible interventions available to mankind. Regular brief immersion in natural
environments effectively reduces cortisol. The best part is that it doesn't take a remote
safari to accomplish. Parks, gardens, or even tree-line streets can all provide the benefits.
The key distinction here is between chronic elevation and acute spikes. Acute spikes help
you respond to challenges and then return to baseline. Chronic elevation is where the problems arise.
Now let's talk about leptin and grelin, two hormones that control your appetite and your energy balance.
These work in opposition to each other, creating an interconnected dynamic for managing food and energy storage.
So leptin originates from your fat cells or adipocytes.
As your fat stores grow larger, leptin levels rise, sending signals to your brain to suppress your appetite and elevate your energy expenditure.
Grelin, produced mainly in your stomach, does the opposite.
it. It stimulates hunger and it promotes fat storage, especially when your stomach is empty.
A 2024 study detailed how these pathways influence hunger and satiety through interactions
with different brain systems. One part of your brain, called the hypothalamus,
handles basic appetite regulation, while a different part of your brain, the limbic system,
adds emotional and reward-based eating behaviors to the mix. This interplay can get even more complicated.
An analysis showed that when you consume less calories, ghrelin levels increase,
while leptin levels decrease. While that might sound good to not be eating a lot, many people
don't know that eating less can actually create challenges for weight management. Your body interprets
calorie restriction as starvation and responds by ramping up hunger signals while reducing the
unful signal. While intermittent fasting and doing the occasional water fast has its place in protecting
your health and metabolism, living in a constant calorie restriction may be messing with your hormone
balance. In addition, follow-up research revealed that leptin can do so much more than suppress your
appetite. It plays a role in many different systems, including reproductive health and immune
function. Specifically, when leptin levels drop too low, women can stop ovulating and it can cause
anyone to experience problems with their immune responses. Perhaps most importantly,
recent research has identified leptin resistance as a major driver of obesity. A major study in
the field examined leptin-resistant mice that also had a protein called M.M.
M.P2 knocked out. When these mice were fed high fat diets, they gained significantly less weight than
expected, while the mice with the protein grew to enormous sizes. The picture of them is crazy
to see, and I'll link the study below so you can take a look for yourself. This suggests that
MMP2 might break down leptin receptors contributing to the resistance. Bringing back leptin sensitivity
could be a breakthrough approach to weight management. To test these specific hormones,
it's going to be important to know how they interact with your body.
The most comprehensive evaluations include both fasting and post-meal sampling
for dynamic hormone profiling.
Balancing these hormones through natural means
focuses on supporting the normal function of these appetite control systems.
Sleep deprivation disrupts both hormones,
leading to increase grelin and decrease leptin sensitivity.
Sufficient protein intake stabilizes grelin and supports satiety.
Protein requires more energy to digest and metabolize
It provides longer lasting fullness compared to carbohydrates or fats alone.
Eating more processed foods actually prevents the amful signaling pathway from working properly.
These foods are engineered to hijack normal appetite controls, leading to overconsumption
and hormonal dysregulation.
Another way to stay at ideal levels is maintaining regular meal timing, which helps align
leptin and grelin rhythms.
Your body thrives on predictable patterns, and irregular eating schedules can disrupt the natural
flow of these appetite hormones.
Another method is through regular physical activity. Exercise enhances leptin sensitivity,
meaning your brain becomes more responsive to the hormone's appetite-suppressing effects.
Chronic stress management, once again, is so important because elevated cortisol disrupts
both leptin and ghrelin. Stress can override normal appetite controls, leading to emotional
and binge eating and cravings for high-calorie comfort foods. Now, these three hormones don't
work in isolation. Chronic cortisol elevation disrupts leptin sensitivity and can increase
grelin production. Poor sleep affects all three, raising cortisol while disrupting leptin
and grel imbalance. Irregular eating patterns stress the cortisol system while confusing the
appetite regulation. In addition, the modern food environment presents new challenges to hormonal
regulation. Ultra-processed foods, irregular eating schedules, chronic stress, and inadequate
sleep all contribute to hormonal dysfunction that makes maintaining healthy weight and managing
stress increasingly difficult. Unfortunately, some people struggle with weight management
even when eating less food. When leptin receptors become less sensitive, the brain doesn't
receive the proper signals leading to continued hunger, even with enough energy stores.
The good news is that these systems respond to lifestyle interventions. Supporting healthy
cortisol patterns through stress management, sleep hygiene, and nature exposure creates the
foundation for overall hormonal maintenance. Appetite balance responds to consistent sleep
schedules, regular meal timing, adequate protein intake, and minimizing processed foods.
These aren't complicated, but they require consistency to create lasting change.
If this type of content interests you and you'd like to learn how to apply science in specific
ways to your own journey, I invite you to join my VIP community. If exclusive content,
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You'll get access to our health optimization guides,
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It's a closer look at how to put these ideas into practice.
Our community is filled with like-minded people just like you.
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Then just click the link below in the show notes.
and skip being a listener and become an insider.
We're giving you the tools to take over your own health
because the key insight is that your hormones respond
to your daily choices.
The foods you eat, how well you sleep,
how you manage stress,
and whether you spend time in nature
all directly influence these powerful chemical messengers.
When you align your lifestyle
with how these systems are designed to function,
you gain the ability to take control
of your stress resilience, your appetite regulation,
and your overall health in significant ways.
and that's just science.
