Habits and Hustle

Episode 511: Dr. Mindy Pelz: Fix Your Metabolism with the Right Type of Fast

December 16, 2025

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  • Dr. Mindy Pelz's career skyrocketed following a viral interview on Stephen Bartlett's podcast, despite a widely publicized misquote regarding testosterone increase from fasting. 
  • The primary goal of fasting is to prevent blood sugar spikes, meaning the quality of consumed beverages (like coffee) and ingredients (like fats or sweeteners) matters significantly in maintaining a true fasted state. 
  • Fasting protocols should be tailored to specific goals (e.g., gut repair at 24 hours, dopamine reset at 48 hours), and active individuals must adjust their fasting windows or incorporate nutrient-rich coffee (like Stacy Sims' protein coffee) to support performance. 
  • Long-term use of GLP-1 drugs may lead to body acclimation, reduced effectiveness, and a return to previous weight if the root cause of being overweight is not addressed through lifestyle changes. 
  • Women struggling with fertility should implement cycle-based fasting: fasting and potentially keto during the front half of the cycle to support estrogen, followed by eating healthy carbs and avoiding fasting in the back half to support progesterone production. 
  • Hormone replacement therapy (HRT) efficacy depends heavily on metabolic health and low toxic load, as toxins can block cellular receptor sites, preventing the body from properly utilizing exogenous hormones. 

Segments

Viral Misquote and Career Impact
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(00:00:01)
  • Key Takeaway: A misquoted statistic about testosterone increase during fasting led to public bullying but ultimately caused Dr. Pelz’s career to skyrocket.
  • Summary: Dr. Mindy Pelz’s interview on Stephen Bartlett’s podcast gained 10 million views in a month, significantly boosting her visibility. The viral moment stemmed from misquoting a study, stating a 1300% testosterone increase in men fasting 24 hours when the study actually referred to growth hormone. Despite the negative attention and bullying from influencers, the controversy defined her career trajectory.
Biggest Fasting Mistakes
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(00:08:26)
  • Key Takeaway: The biggest mistake people make when fasting is consuming anything that causes a blood sugar rise, even if it’s not solid food.
  • Summary: Fasting is defined by maintaining stable blood sugar; drinking green juice can pull one out of a fasted state, whereas black coffee generally does not. The quality of coffee matters, as chemicals in conventionally sourced coffee can interrupt the healing process like autophagy. Adding a fat like MCT oil to coffee can suppress hunger and promote ketone production.
Six Core Types of Fasting
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(00:13:19)
  • Key Takeaway: Different fasting durations target distinct physiological benefits, ranging from intermittent fasting for food restriction to 48-hour fasts for dopamine resetting.
  • Summary: Intermittent fasting (12-15 hours) is a common food restriction window, while 17 hours stimulates autophagy (cellular detox). A 24-hour fast is recommended weekly for gut repair by stimulating intestinal stem cell production. The 36-hour fast is effective for breaking weight loss resistance, and a 48-hour fast resets the brain’s dopamine system.
Fasting Research Methodology
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(00:16:04)
  • Key Takeaway: Dr. Pelz developed her fasting benchmarks through three years of intensive research on PubMed, followed by rigorous patient and community practice.
  • Summary: Dr. Pelz spent approximately 20 hours per week researching peer-reviewed journals on PubMed for about three years to understand concepts like autophagy. She then tested these fasting durations with her clinical patients and online communities, observing real-world results to boil down the six core effective fasts.
Fasting Mimicking Diet Efficacy
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(00:19:35)
  • Key Takeaway: The Fast Mimicking Diet (FMD) can induce similar benefits to water fasting, including stimulating pancreatic cell regrowth in diabetic models.
  • Summary: FMD, like Prolon, aims to achieve similar benefits to water fasting by keeping calories under 800 and limiting carbohydrates. Research shows that five days of FMD monthly for three months can initiate the regrowth of insulin-producing cells in the pancreas of type one diabetics. Water fasts may induce ketosis faster (within 24 hours) than FMD due to the immediate lack of carbohydrates.
Fasting for Active Individuals
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(00:24:40)
  • Key Takeaway: Active individuals should strategically align longer fasts (17-24 hours) with recovery days, reserving intense training for days when they break their fast with protein.
  • Summary: Endurance athletes often find fasting difficult during intense workouts, suggesting heavy training requires pre-workout fuel like protein. For active people, a 24-hour fast is best scheduled on a non-training recovery day to allow for system cleanup. Stacy Sims advocates for a protein-packed coffee before intense workouts to stimulate hormones and maintain ketosis without halting the hormonal cycle.
Who Should Avoid Fasting
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(00:26:25)
  • Key Takeaway: Fasting is contraindicated for individuals with eating disorders, pregnant women, and nursing mothers should limit fasts to under 17 hours to avoid toxin dumping.
  • Summary: People with disordered eating must approach fasting cautiously, often requiring stabilization of their relationship with food first, as it can trigger restrictive behaviors. Women who are pregnant should absolutely not fast. Nursing mothers should avoid fasts exceeding 17 hours because toxins released during fasting can transfer to the baby.
Fasting Through Menopause
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(00:30:12)
  • Key Takeaway: Fasting is an essential tool for menopausal women to combat increased insulin resistance and restore mental clarity by promoting ketone production for brain energy.
  • Summary: Estrogen decline during menopause leads to greater insulin resistance, causing many women to gain weight; fasting counters this by forcing the body to burn fat for ketones. Ketones sharpen mental clarity and increase GABA, a calming neurotransmitter, which helps combat menopausal brain fog. While endurance athletes may disagree, longer fasts are crucial for non-fit menopausal women needing brain energy.
Supplement Cycling Protocol
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(00:44:33)
  • Key Takeaway: Supplements should be cycled every 90 days, taking a break of two to four weeks, because the body adapts and becomes ‘deaf’ to continuous intake.
  • Summary: Taking the same supplement daily leads to diminishing returns as the body acclimates, rendering the supplement ineffective over time. Dr. Pelz recommends cycling supplements every 90 days, sometimes completely stopping them to see if they are still necessary. This principle of taking breaks applies to lifestyle habits like exercise and diet as well.
Microbiome Diversity and Cravings
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(00:48:27)
  • Key Takeaway: Eating the same foods repeatedly starves out diverse gut microbes, leading to a monoculture that fuels specific cravings and negatively impacts mental health.
  • Summary: Gut microbes, not human cells, are primarily fueled by food, and they act as brokers, breaking down nutrients for the body. Eating a limited variety of foods strengthens dominant microbes that may drive cravings for sugar or carbs. Lack of microbial diversity can lead to reduced serotonin production, potentially causing depression or anxiety.
GLP-1 Drugs vs. Natural Production
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(00:52:07)
  • Key Takeaway: GLP-1 hormone, which regulates hunger, is naturally produced by gut microbes, making toxic fats a root cause of deficiency that pharmaceuticals address externally.
  • Summary: The GLP-1 hormone is produced by the gut microbiome; therefore, obesity linked to ultra-processed foods and toxic oils is killing the microbes responsible for its production. Yerba Mate tea and high-fiber vegetables feed the microbes that produce GLP-1 naturally, offering a root-cause solution. GLP-1 drugs mimic this hormone, but long-term use may cause the body to stop producing its own, similar to supplement acclimation.
GLP-1 Drug Long-Term Effects
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(00:55:55)
  • Key Takeaway: Prolonged use of GLP-1 drugs can lead to body acclimation, diminishing effectiveness as the body stops producing its own GLP-1.
  • Summary: People using GLP-1 drugs for too long may find the medication less effective as their body acclimates, leading to hunger returning. This occurs because the body signals its microbes that external GLP-1 is sufficient, halting natural production. Without lifestyle changes addressing the root cause of weight gain, users risk regaining weight after cessation.
Optimizing Meal Order for Microbes
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(00:57:22)
  • Key Takeaway: Eating food in the order of protein first, then fiber, and finally carbohydrates can positively affect the microbes that produce GLP-1.
  • Summary: To support gut health and GLP-1 production, the recommended eating order is protein first, followed by fiber (vegetables), and carbohydrates last. This sequence helps manage glucose response, contrasting with eating high-carbohydrate items like sweet potatoes last, even if they are healthy.
Critique of Quick-Fix Medications
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(00:58:35)
  • Key Takeaway: The goal of health should be avoiding lifelong addiction to medications like blood pressure drugs or weight loss aids by utilizing lifestyle tools.
  • Summary: There is a preference for quick fixes over learning self-management lifestyle tools, which drives the popularity of online courses despite the information being accessible. The speaker expresses nervousness about drugs like GLP-1 agonists that lack decades of long-term safety data, drawing parallels to past failed weight loss trends like the Lap-Band surgery.
Fasting Protocol for Fertility
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(01:04:05)
  • Key Takeaway: Cycle-based fasting—fasting/keto front half, carb-eating back half—can restore fertility by meeting opposing hormonal needs for estrogen and progesterone.
  • Summary: Estrogen requires low glucose/insulin sensitivity for egg release, while progesterone requires high glucose for production, creating opposing needs across the menstrual cycle. A protocol of fasting/keto in the first half and eating healthy carbs in the second half successfully helped multiple patients conceive after long struggles.
HRT Nuance and Cellular Health
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(01:07:42)
  • Key Takeaway: The body must be metabolically healthy and have low toxic load for exogenous hormones, even bioidentical HRT, to be effectively received by cell receptor sites.
  • Summary: Simply taking bioidentical hormones does not guarantee improvement if the body is not metabolically ready or if toxins are blocking receptor sites. Weight gain on HRT can signal poor cellular reception, emphasizing the need to address toxic load from plastics and endocrine disruptors first.
Menopause Brain Rewiring
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(01:15:00)
  • Key Takeaway: The natural decline of estrogen during menopause signals the brain to prune and rewire, leading to stronger mental clarity and unilateral focus necessary for leadership roles.
  • Summary: The evolutionary purpose of menopause is to prepare women for leadership by allowing estrogen levels to drop, which enhances cognitive function. Women should prioritize lifestyle factors like stress management and fasting over simply trying to maintain 35-year-old hormone levels to support this beneficial brain change.
Creatine Supplementation Timing
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(01:16:51)
  • Key Takeaway: Creatine supplementation becomes necessary post-menopause because the body naturally stops producing it when estrogen levels decline.
  • Summary: Since estrogen stimulates natural creatine production, women need to supplement when estrogen is low to support brain function. The recommended protocol involves a two-week mega-dose of 20 grams, followed by a maintenance dose of five grams, cycling off every 90 days.
Peptides as Restored Biological Processes
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(01:20:15)
  • Key Takeaway: Peptides are beneficial because they reinstate natural biological processes that the body fails to initiate due to insufficient amino acid intake from a non-diverse diet.
  • Summary: Peptides are sequences of amino acids that initiate specific biological processes, such as GLP-1 production or BDNF creation. Using peptides like Cerebrolysin to boost BDNF can enhance focus, but users must monitor side effects like compromised sleep.
Apple Cider Vinegar for Fasting
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(01:24:07)
  • Key Takeaway: Apple cider vinegar stabilizes blood sugar, making it useful during fasting to manage hunger and prevent excessive insulin spikes after meals.
  • Summary: Taking one tablespoon of apple cider vinegar in water before a meal or during a fast helps stabilize blood sugar levels. This practice is beneficial for fasters managing hunger and for pre-diabetics whose blood sugar is too high to drop effectively during a fasted state.