Fasting & Health Expert: Tune Into Your Body's Natural Power To Heal

Pelz further explains that modern life creates an evolutionary mismatch for women. Unlike hunter-gatherer societies where women's nervous systems experienced a natural rhythm of stress and relaxation, today's women are caught in a relentless cycle of "go, go, go." This constant activation of the sympathetic nervous system, combined with societal pressures to perform and look a certain way, disrupts hormonal balance and overall health. The mismatch lies in the fact that women's bodies were designed for cyclical rest and activity, but modern culture demands continuous output, leading to hormonal and nervous system dysregulation.

The Hormonal Hierarchy and the Central Role of Insulin

A key insight Dr. Pelz shares is the concept of the hormonal hierarchy, where insulin plays a pivotal role in regulating the sex hormones estrogen, progesterone, and testosterone. Insulin resistance, a hallmark of metabolic dysfunction, disrupts this balance and is often the root cause of many hormonal issues women face, including PCOS, infertility, and severe menopause symptoms. Pelz highlights that insulin is essentially the "kingmaker" hormone because its dysfunction cascades down to affect reproductive hormones.

Above insulin in this hierarchy is cortisol, the stress hormone, which exacerbates insulin resistance by signaling the body to prioritize immediate energy use over long-term metabolic health. At the top of the hierarchy is oxytocin, which can calm cortisol and thereby indirectly improve insulin sensitivity and hormonal balance. This layered understanding underscores the complexity of women's hormonal health and the importance of addressing metabolic health as a foundation for overall well-being.

Insulin Resistance and Metabolic Health Explained

Dr. Pelz offers a clear explanation of insulin resistance for those unfamiliar with the term. When we eat, glucose levels rise, prompting the pancreas to release insulin, which escorts glucose into cells to be used for energy. However, chronic overconsumption of glucose overwhelms cells, causing them to reject insulin and glucose, which then get stored as fat. This protective mechanism, while lifesaving, leads to insulin resistance—a state where cells no longer respond effectively to insulin, impairing energy production and promoting fat storage.

She also discusses how stress and poor sleep contribute to insulin resistance by elevating cortisol, which signals the body to prepare for "fight or flight," moving glucose to muscles and blocking its uptake by other cells. This misalignment between perceived threat and actual activity (e.g., sitting on a couch but the body acting as if fleeing a predator) worsens metabolic dysfunction. Pelz stresses that insulin resistance is not just about diet but a complex interplay of lifestyle factors, including stress management and sleep quality.

Women's Unique Hormonal Cycles and Insulin Sensitivity

One of the most interesting parts of the conversation is Dr. Pelz's explanation of how insulin sensitivity fluctuates throughout a woman's menstrual cycle. During the first half of the cycle, from menstruation to ovulation, women are more insulin sensitive, which supports estrogen's role in preparing the body for potential pregnancy. In contrast, the second half of the cycle, especially the week before menstruation, sees increased insulin resistance due to rising progesterone levels, which require more glucose to support the shedding of the uterine lining.

This cyclical variation explains common experiences such as premenstrual carb cravings and mood changes. Pelz points out that these cravings are not a sign of weakness or failure but a biological signal that the body needs more glucose to produce progesterone and complete the cycle. Understanding this rhythm allows women to better align their eating and fasting practices with their hormonal needs, rather than fighting against their biology.

Fasting as a Healing Tool for Women

Fasting emerges as a central theme in Dr. Pelz's approach to women's health. She advocates for fasting as a way to reset insulin sensitivity, promote weight loss, and activate the body's natural healing mechanisms. Importantly, she stresses that fasting must be timed according to the menstrual cycle to be effective and safe. Fasting is most beneficial during the first 20 days of the cycle when estrogen is dominant and insulin sensitivity is higher, but it should be avoided in the luteal phase and especially the week before menstruation when progesterone demands more glucose.

Pelz describes fasting not as a one-size-fits-all prescription but as a flexible lifestyle tool that can be adjusted in length and frequency. From 17-hour intermittent fasts to longer 72-hour fasts, each duration triggers different healing processes, such as autophagy, gut regeneration, fat burning, dopamine system reset, and immune system renewal. She encourages women to experiment with fasting windows and lengths to find what works best for their unique physiology and life circumstances.

Metabolic Switching: The Balance Between Sugar and Fat Burning

A foundational concept Dr. Pelz discusses is metabolic switching—the body's natural ability to alternate between burning glucose (sugar) when food is available and burning fat when fasting. After about 12 hours without food, the body shifts from sugar burning to fat burning, producing ketones that fuel the brain and suppress hunger. This switch is essential for metabolic health and longevity, as constant sugar burning leads to obesity and metabolic disease, while constant fat burning is unsustainable.

Pelz emphasizes that health lies in the rhythm of switching between these two states, much like the nervous system's balance between sympathetic and parasympathetic activity. Fasting trains the body to become efficient at this switch, improving insulin sensitivity and hormonal balance. She warns against extremes—neither constant eating nor excessive fasting is beneficial—and advocates for a balanced, rhythmic approach to eating and fasting.

Fasting and Athletic Performance

Addressing concerns about fasting for athletes, Dr. Pelz acknowledges that intense training phases require adequate fueling and recovery nutrition. However, she also highlights fasting's potential as a recovery tool when used strategically. For example, athletes might avoid fasting on heavy workout days but incorporate fasting on lighter or rest days to reduce inflammation and promote healing.

She shares practical examples from her work with endurance athletes, where fasting windows were tailored around training schedules to optimize performance and recovery. The key takeaway is that fasting is a flexible tool, not a rigid rule, and should be integrated thoughtfully based on individual goals, training intensity, and recovery needs.

The Impact of Modern Lifestyle on Women's Hormonal Health

Dr. Pelz paints a vivid picture of how modern stressors—emotional, physical, and chemical—overwhelm women's nervous and hormonal systems. The constant activation of the stress response elevates cortisol, which disrupts insulin and sex hormone balance, leading to symptoms like weight gain, infertility, and mood disorders. She describes the "patriarchal hex," a cultural pressure on women to do more to prove worthiness, which exacerbates this stress.

This chronic stress environment is a major driver of the hormonal and metabolic dysfunction epidemic among women today. Pelz argues that lifestyle changes, including stress reduction, fasting, and better alignment with natural rhythms, are essential to breaking this cycle. She also highlights the lack of research focused on women, which hampers understanding and treatment of these issues.

Hormone Replacement Therapy and Lifestyle Integration

While acknowledging the benefits of hormone replacement therapy (HRT) for menopausal women, Dr. Pelz cautions that it is not a cure-all. She advocates for combining HRT with lifestyle interventions such as fasting and metabolic health optimization to address the complex neurochemical and hormonal shifts during menopause. Estrogen's decline leads to increased insulin resistance and metabolic challenges, which can be mitigated by ketone production through fasting.

Pelz stresses that menopause is a time for lifestyle recalibration, not just pharmaceutical intervention. Women need to adopt gentler, more supportive routines that honor their changing bodies, including reduced stress, appropriate exercise, and nutritional adjustments. HRT can be a valuable tool within this broader lifestyle framework.

Men's Role in Supporting Women's Hormonal Health

Dr. Pelz highlights the importance of involving men in conversations about women's hormonal health. She explains that men often misunderstand the cyclical nature of women's moods and behaviors, leading to frustration and miscommunication. Educating men about the hormonal fluctuations and neurochemical changes women experience can foster empathy and better support.

She offers practical advice for men to recognize and respect these cycles, such as understanding when women are more irritable or need rest, and adjusting expectations accordingly. Pelz also discusses the neurochemical "upgrade" women undergo during menopause, which can change behaviors and relationship dynamics. Men who engage with these changes openly can strengthen their partnerships and support women's empowerment.

Detoxification, Toxins, and the Body's Healing Capacity

The conversation turns to the pervasive issue of environmental toxins and their impact on women's health. Dr. Pelz describes how modern life exposes women to a "toxic bucket" of chemicals from beauty products, plastics, mold, and processed foods, which accumulate and trigger symptoms. She stresses the importance of daily detox practices, such as sweating, fasting, and consuming liver-supportive bitter greens, to reduce toxic load.

Pelz emphasizes that the body's liver and gut are central to detoxification and that supporting these organs through diet, emotional health, and lifestyle is crucial. She encourages small, manageable changes—like switching to glass water bottles or using air filters—to reduce toxin exposure without overwhelming oneself. Fasting plays a key role by giving the body time to repair and clear toxins naturally.

The Philosophy of Health

Dr. Pelz closes with a powerful message about health as a verb, not a noun. She challenges the notion of health as a destination or object to be obtained and instead frames it as an ongoing daily practice of alignment with one's body and environment.