Dr. Brendan McCarthy

GLP-1 medications like semaglutide and tirzepatide are everywhere right now—but are they actually solving the problem?

In Episode 8 of this 16-part series on ultra-processed foods, Dr. Brendan McCarthy breaks down the truth about GLP-1 medications: how they work, why they can feel like a “miracle,” and where things go wrong when they’re used without proper medical guidance.

This isn’t about shame. It’s about understanding.

GLP-1s can quiet “food noise” and help regulate appetite—but they don’t fix your relationship with food, your metabolism, or the long-term patterns that lead to weight gain. Without structure, nutrition, and proper care, many patients end up with muscle loss, nutrient deficiencies, and rebound weight gain.

In this episode, you’ll learn:

What GLP-1 medications actually do in your body

Why they’re not a long-term solution on their own

The biggest mistakes doctors and clinics make when prescribing them

How ultra-processed foods drive weight gain in the first place

How to use GLP-1s the right way to create lasting change

The goal isn’t dependence—it’s freedom.

If you’re currently on a GLP-1 (or considering it), this episode will change how you think about your treatment plan.

 

Mechanism Anchored References

This episode is not anti medication.

It is about putting GLP 1 therapy in its proper place.

GLP 1 receptor agonists can reduce appetite pressure and alter satiety signaling.

That matters.

But quieter appetite is not the same as full recovery.

Food quality still matters.

Protein still matters.

Muscle still matters.

Structure still matters.

 

References

U.S. Food and Drug Administration. WEGOVY semaglutide injection Prescribing Information. 2025.

Wilding, John P H, et al. Once Weekly Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine, vol. 384, no. 11, 2021, pp. 989 to 1002.

Wilding, John P H, et al. Weight Regain and Cardiometabolic Effects After Withdrawal of Semaglutide The STEP 1 Trial Extension. Diabetes Obesity and Metabolism, vol. 24, no. 8, 2022, pp. 1553 to 1564.

Hall, Kevin D, et al. Ultra Processed Diets Cause Excess Calorie Intake and Weight Gain An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metabolism, vol. 30, no. 1, 2019, pp. 67 to 77.

Neeland, Ian J, et al. Changes in Lean Body Mass with Glucagon Like Peptide 1 Based Therapies and Mitigation Strategies. Diabetes Obesity and Metabolism, 2024.

Wilding, John P H, et al. Impact of Semaglutide on Body Composition in Adults with Overweight or Obesity Exploratory Analysis of the STEP 1 Study. 2021.

Everitt, Barry J, and Trevor W Robbins. Drug Addiction Updating Actions to Habits to Compulsions Ten Years On. Annual Review of Psychology, vol. 67, 2016, pp. 23 to 50.

Monteiro, Carlos A, et al. The UN Decade of Nutrition the NOVA Food Classification and the Trouble with Ultra Processing. Public Health Nutrition, vol. 21, no. 1, 2018, pp. 5 to 17.

 

Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.

 

👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.

 

📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604

 

📲 Follow Dr. McCarthy:

Instagram: @drbrendanmccarthy

TikTok: @drbrendanmccarthy

Website: www.protealife.com

 

💬 Got a question or topic for a future episode? Let us know in the comments!

Craving junk food when you’re stressed isn’t a lack of discipline — it’s biology.

In this episode, Dr. Brendan McCarthy breaks down what ultra-processed and hyper-palatable foods actually do inside your body — from your metabolism to your hormones, your brain, and your stress response.

But this isn’t about guilt or shame.

It’s about understanding what you’re up against — especially as a parent trying to make better choices in a world designed to make that difficult.

You’ll learn:

What ultra-processed foods really are

How they impact your endocrine system and metabolism

Why stress makes you crave sugar and processed foods

Why shame around food doesn’t work (and never will)

Simple, realistic ways to improve your family’s eating habits

This episode is about taking back control — without perfection, and without guilt.

 

Mechanism-Anchored References Monteiro, Carlos A., et al. “Ultra-Processed Foods: What They Are and How to Identify Them.” Public Health Nutrition, vol. 22, no. 5, 2019, pp. 936–941. Hall, Kevin D., et al. “Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake.” Cell Metabolism, vol. 30, no. 1, 2019, pp. 67–77.e3. doi:10.1016/j.cmet.2019.05.008. Rush, E. Catherine, et al. “The Impact of Ultra-Processed Foods on Pediatric Health.” Nutrition Reviews, 2024. doi:10.1093/nutrit/nuae051. Ventura, Alison K., and John Worobey. “Early Influences on the Development of Food Preferences.” Current Biology, vol. 23, no. 9, 2013, pp. R401–R408. doi:10.1016/j.cub.2013.02.037. Mennella, Julie A., et al. “Preferences for Salty and Sweet Tastes Are Elevated and Related to Each Other during Childhood.” PLOS ONE, vol. 9, no. 3, 2014, e92201. doi:10.1371/journal.pone.0092201. Roberto, Christina A., et al. “Influence of Licensed Characters on Children’s Taste and Snack Preferences.” Pediatrics, vol. 126, no. 1, 2010, pp. 88–93. doi:10.1542/peds.2009-3433. Swindle, Taren, et al. “Pester Power: Examining Children’s Influence as an Active Component of the Family Food Environment.” Journal of Nutrition Education and Behavior, vol. 52, no. 8, 2020, pp. 801–807. doi:10.1016/j.jneb.2020.06.002. Pérez-Escamilla, Rafael, et al. “Responsive Feeding Recommendations: Harmonizing Integration into Dietary Guidelines for Infants and Young Children.” Current Developments in Nutrition, vol. 5, no. 6, 2021, nzab076. doi:10.1093/cdn/nzab076. Puhl, Rebecca M., and Chelsea A. Heuer. “Obesity Stigma: Important Considerations for Public Health.” American Journal of Public Health, vol. 100, no. 6, 2010, pp. 1019–1028. doi:10.2105/AJPH.2009.159491. World Health Organization. Set of Recommendations on the Marketing of Foods and Non-Alcoholic Beverages to Children. World Health Organization, 2010.

 

Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.

 

👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.

 

📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604

 

📲 Follow Dr. McCarthy:

Instagram: @drbrendanmccarthy

TikTok: @drbrendanmccarthy

Website: www.protealife.com

 

💬 Got a question or topic for a future episode? Let us know in the comments!

In this episode, Dr. Brendan McCarthy—Chief Medical Officer at Protea Medical Center—dives into one of the most misunderstood topics in health:

Why does it feel like you can’t stick to a diet… even when you’re trying your best?

This isn’t about willpower.
It’s not a character flaw.
And it’s not your fault.

Dr. McCarthy breaks down the biology behind stress, cravings, and weight gain—explaining how chronic stress rewires your brain, alters decision-making, and drives you toward hyper-palatable, ultra-processed foods.

 

YouTube citations : 

1. Arnsten, Amy F. T. “Stress Weakens Prefrontal Networks: Molecular Insults to Higher Cognition.” Nature Neuroscience, vol. 18, no. 10, 2015, pp. 1376–1385.

Why it is here: Foundational paper for the claim that uncontrollable stress increases catecholamine signaling in the prefrontal cortex and degrades higher-order control, working memory, and inhibition. This is one of the strongest anchors for the idea that stress makes the pause smaller.  

2. Schwabe, Lars, et al. “Concurrent Glucocorticoid and Noradrenergic Activity Shifts Instrumental Behavior from Goal-Directed to Habitual Control.” Journal of Neuroscience, vol. 30, no. 24, 2010, pp. 8190–8196.

Why it is here: One of the most important papers for your “click-boom” model. It shows that stress chemistry can bias behavior away from goal-directed control and toward habit-like responding. That is not a morality argument. It is control architecture.  

3. Plessow, Franziska, et al. “The Stressed Prefrontal Cortex and Goal-Directed Behaviour: Acute Psychosocial Stress Impairs the Flexible Implementation of Task Goals.” Experimental Brain Research, vol. 216, no. 3, 2012, pp. 397–408.

Why it is here: Strong support for the claim that acute psychosocial stress impairs flexible goal implementation. Useful when you want to say that under stress, the person may still know what matters but have reduced access to that guidance in the moment.  

4. Maier, Silvia U., et al. “Acute Stress Impairs Self-Control in Goal-Directed Choice by Altering Multiple Functional Connections within the Brain’s Decision Circuits.” Neuron, vol. 87, no. 3, 2015, pp. 621–631.

Why it is here: Excellent for the food-choice angle. This paper supports the idea that stress increases the weight of immediately rewarding attributes and reduces self-control. In your language, the cue gets louder and the future gets quieter.  

5. Epel, Elissa, et al. “Stress May Add Bite to Appetite in Women: A Laboratory Study of Stress-Induced Cortisol and Eating Behavior.” Psychoneuroendocrinology, vol. 26, no. 1, 2001, pp. 37–49.

Why it is here: Classic paper, directly in women, directly in Psychoneuroendocrinology. Strong support for linking stress physiology, cortisol reactivity, and post-stress eating behavior.  

6. Giddens, Emily E., et al. “The Influence of Stress on the Neural Underpinnings of Disinhibited Eating: A Systematic Review and Future Directions for Research.” Reviews in Endocrine and Metabolic Disorders, 2023.

Why it is here: A modern review tying stress to food-related reward sensitivity, interoception, and cognitive control in disinhibited eating. Good bridge reference for the overall brain-food-stress model.  

7. Lyu, Z., et al. “Acute Stressors Reduce Neural Inhibition to Food Cues and Increase Eating Among Binge Eating Disorder Symptomatic Women.” Frontiers in Behavioral Neuroscience, 2016.

Why it is here: Helpful for the specific claim that acute stress can reduce inhibitory neural responsiveness to food cues and increase eating in vulnerable women. Strong fit for the cue-reactivity piece.

 

Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.

 

👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.

 

📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604

 

📲 Follow Dr. McCarthy:

Instagram: @drbrendanmccarthy

TikTok: @drbrendanmccarthy

Website: www.protealife.com

 

💬 Got a question or topic for a future episode? Let us know in the comments!

Is weight gain really about willpower… or is something deeper going on?

In this episode, Dr. Brendan McCarthy, Chief Medical Officer at Protea Medical Center, breaks down the real biology behind stress, cravings, and weight gain—and why blaming yourself (or cortisol) is missing the point.

You’ll learn:

Why chronic stress rewires your metabolism

How stress drives cravings for ultra-processed foods

The truth about cortisol and fat storage

Why “just have more discipline” is bad medicine

How ultra-processed foods hijack your hunger and reward systems

The key to rebuilding control and agency

This isn’t about motivation—it’s about understanding your biology so you can finally work with your body instead of against it.

If you’ve ever felt stuck, frustrated, or blamed for your weight… this episode is for you.

 

Mechanism-Anchored References

    1.    Glucocorticoids, stress, and eating

Kuckuck S, van der Valk ES, Scheurink AJW, et al. Glucocorticoids, stress and eating: the mediating role of appetite-regulating hormones. Obesity Reviews. 2023.

Supports the claim that stress biology and glucocorticoid signaling can alter appetite regulation and eating behavior.  

    2.    Stress-level glucocorticoids can increase hunger

Bini J, et al. Stress-level glucocorticoids increase fasting hunger and alter cerebral blood flow in neural regions that regulate food intake. 2022.

Supports the claim that stress-level glucocorticoid exposure can increase hunger and affect food-intake regulation.  

    3.    Stress-obesity link / HPA-axis context

Lengton R, et al. Glucocorticoids and HPA axis regulation in the stress-obesity link. 2024.

Supports the broader claim that chronic stress and glucocorticoid biology are relevant to obesity risk and metabolic dysregulation.  

    4.    Sleep loss changes appetite and metabolism

Van Cauter E, et al. Metabolic consequences of sleep and sleep loss. 2008.

Supports the claim that inadequate sleep alters appetite regulation and harms carbohydrate metabolism.  

    5.    Sleep deprivation impairs glucose handling and raises appetite pressure

Knutson KL. The metabolic consequences of sleep deprivation. 2007.

Supports the claim that sleep loss can worsen glucose metabolism, appetite drive, and obesity risk.  

    6.    Circadian disruption and metabolic dysfunction

Depner CM, et al. Metabolic consequences of sleep and circadian disorders. 2014.

Supports the claim that circadian disruption and sleep deficiency contribute to metabolic dysregulation and weight gain risk.  

    7.    Ultra-processed food and reward-system activation

Calcaterra V, et al. Ultra-Processed Food, Reward System and Childhood Obesity. 2023.

Supports the claim that ultra-processed foods interact with reward pathways in ways that can drive intake beyond simple calorie math.  

    8.    Ultra-processed food and metabolic dysfunction

Vitale M, et al. Ultra-Processed Foods and Human Health: A Systematic Review and Meta-Analysis. 2023.

Supports the claim that higher UPF consumption is associated with obesity and metabolic disease risk.  

    9.    Stress and poorer diet quality / emotional eating

Shatwan IM, et al. Association between perceived stress, emotional eating, and diet quality. 2024.

Supports the claim that higher perceived stress is associated with worse dietary patterns and emotional eating.  

    10.    Compassion-based framing and adherence

Sirois FM, et al. Self-Compassion and Adherence in Five Medical Samples. 2018.

Supports the closing point that shame is a weak intervention model and that compassion-linked framing may better support adherence and change.  

 

Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.

 

👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.

 

📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604

 

📲 Follow Dr. McCarthy:

Instagram: @drbrendanmccarthy

TikTok: @drbrendanmccarthy

Website: www.protealife.com

 

💬 Got a question or topic for a future episode? Let us know in the comments!

We’ve all heard it: calories in vs. calories out.
And while that’s not wrong… it’s not complete.

Dr. McCarthy breaks down the three major approaches to weight loss:

1. Calorie restriction

2. Insulin management (low-carb, keto, etc.)

3. Exercise & performance

…and explains why each works—but still falls short on its own.

The missing piece?
The signal your food sends to your body.

This episode explores how ultra-processed foods:

- Disrupt hunger and satiety signals

- Spike blood sugar and drive cravings

- Bypass normal metabolic pathways

- Create instability in an otherwise well-designed system

Citations: Protea Mechanism-Anchored Evidence Map

Episode 4 — Insulin Is Not the Enemy: Misrouted Energy Is

Below are key scientific principles and supporting literature behind this episode. This is not about “proving a point”—it’s about giving you a transparent look at how these conclusions are built.

1. Energy Balance Is Real—But Regulated
Body weight isn’t controlled by calories alone. Hormones, the brain, appetite, and behavior all regulate how energy is used, stored, and burned.
Key refs: Hall et al. (2012); Speakman & Westerterp (2010)

2. Insulin Is a Traffic Director, Not the Villain
Insulin helps route nutrients (to muscle, liver, or fat). It doesn’t independently cause obesity—it directs where energy goes.
Key refs: Saltiel & Kahn (2001); Petersen & Shulman (2018)

3. No Single Model Explains Everything
Calories matter. Hormones matter. Behavior matters.
A complete model integrates all three—not just one.
Key refs: Ludwig et al. (2022); Hall & Chow (2015)

4. Exercise Helps—But Isn’t the Full Solution
Exercise improves metabolism and health, but often doesn’t override poor dietary signaling due to compensation (hunger, adaptation).
Key refs: Swift et al. (2014); Pontzer et al. (2016)

5. Food Is More Than Calories—It’s Information
Food sends signals that impact hunger, metabolism, hormones, and brain reward systems—not just energy intake.
Key refs: Morton et al. (2006); Friedman (2004)

6. Ultra-Processed Foods Disrupt Regulation
These foods increase intake by altering satiety, speed of eating, and reward pathways—leading to overeating.
Key refs: Hall et al. (2019); Monteiro et al. (2019)

7. Fructose Is Metabolized Differently
Fructose is processed primarily in the liver and more readily contributes to fat production (de novo lipogenesis).
Key refs: Tappy & Lê (2010); Softic et al. (2020)

8. Muscle & Protein Drive Metabolic Stability
Protein supports satiety and thermogenesis, while muscle helps regulate glucose and overall metabolic health.
Key refs: Leidy et al. (2015); DeFronzo et al. (2009)

 

Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.

 

👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.

 

📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604

 

📲 Follow Dr. McCarthy:

Instagram: @drbrendanmccarthy

TikTok: @drbrendanmccarthy

Website: www.protealife.com

 

💬 Got a question or topic for a future episode? Let us know in the comments!