Overview of How to Fast for Fat Loss, Hormones, and Better Sex with Dr. Mindy Pelz
In this conversation, Lewis Howes interviews fasting expert and author Dr. Mindy Pelz about how fasting affects fat loss, hormones, energy, aging, and sexual health—especially for women. The central message is that fasting can be powerful, but women should not fast like men. Instead, Dr. Pelz argues that women should align fasting, exercise, food intake, and recovery with their menstrual cycle to support insulin sensitivity, hormone balance, fertility, mood, and long-term health.
Main Themes and Takeaways
Fasting is about when you eat, not just what you eat
- Dr. Pelz explains that the body has two energy systems:
- Fed state: energy created when you eat
- Fasted state: energy created when you stop eating long enough
- Around 8–10 hours without food, the body can switch into a ketogenic/fat-burning state.
- In this state, the body produces ketones, which can:
- reduce hunger
- increase calmness
- improve mental clarity
- create more steady energy
- Her broader point: constantly eating prevents the body from accessing this repair and fat-burning mode.
Fasting is a recovery tool, not just a weight-loss tactic
- She compares fasting to exercise:
- stress the body a little
- then recover
- recovery is where healing and strengthening happen
- If you never give the body a break from eating, you may accelerate aging and make fat loss harder.
Women should fast differently than men
- Dr. Pelz strongly emphasizes that women are not small men hormonally.
- Women have to account for:
- menstrual cycle
- estrogen
- progesterone
- testosterone
- cortisol/stress
- She says women can become hormonally stressed if they fast too aggressively, too often, or at the wrong time in their cycle.
The Menstrual Cycle Framework She Recommends
Days 1–10: Best time for more intensity
- Day 1 starts with bleeding.
- The first 10 days are the estrogen-building phase.
- This is generally the best window for:
- longer fasts
- harder workouts
- lower carb intake
- more productivity and drive
- She notes that estrogen supports:
- focus
- mood
- sociability
- motivation
- mental sharpness
Days 11–15: Ovulation / “manifestation” phase
- This is when women get a surge of:
- testosterone
- estrogen
- some progesterone
- Dr. Pelz says this is often the best time to:
- lift heavy
- build muscle
- pursue big projects
- socialize and network
- lean into libido and creativity
- She describes this as a time when women can feel especially powerful and driven.
Days 16–19: A better window for longer fasting
- After ovulation, hormone levels drop.
- Dr. Pelz says women can often tolerate:
- longer fasts
- more aggressive fasting windows
- more metabolic flexibility during this period
Days 20 until the next period: Nurture and recovery phase
- Progesterone rises here and is more sensitive to stress.
- This is the time to:
- reduce fasting
- scale back intense workouts
- prioritize sleep and recovery
- use gentler movement like yoga, walking, Pilates, or hiking
- She says women often crave carbs and chocolate here because the body needs more glucose to support progesterone.
Why Fasting Can Help Hormones, Libido, and Fertility
Blood sugar and insulin matter for sex hormones
- According to Dr. Pelz, insulin sensitivity is foundational for balanced sex hormones.
- If cortisol is high, insulin resistance rises, which can disrupt hormone balance and fertility.
- She argues fasting can improve insulin regulation and therefore help restore cycles and support conception.
Stress can suppress reproduction
- Her big idea: the body prioritizes survival first, reproduction second.
- If the body senses too much stress—emotional, physical, sleep-related, or environmental—it may downshift reproductive function.
- She connects this to:
- missed periods
- fertility issues
- low libido
- PMS
- hormonal imbalance
Feeling safe matters hormonally
- Dr. Pelz repeatedly emphasizes that women’s bodies need to feel safe.
- She links hormone health to:
- emotional regulation
- supportive relationships
- adequate rest
- reduced trauma/stress
- community and connection
Important Guidance on Food, Digestion, and Night Eating
Eat when it’s light out
- She recommends eating during daylight hours because:
- melatonin rises at night
- insulin sensitivity worsens in the dark
- food eaten late is more likely to be stored as fat
- Night eating can also impair digestion and contribute to gut issues.
Avoid large meals right before bed
- Her view is that digestion slows at night, so:
- food is not broken down as efficiently
- nutrients may be absorbed less well
- fermentation and gut imbalance can increase
- She does allow that a small amount of dark chocolate or a light snack is not the same as a full meal.
Men, Women, and Fasting: Key Differences
Men can generally fast more consistently
- Dr. Pelz says men don’t have the same monthly hormonal fluctuations, so fasting is usually easier to sustain consistently.
- But she still says men should not fast forever without occasional feasting or refeeding.
Women need cycle-aware fasting
- For women, the key is not constant fasting, but cycling fasting based on hormone state and recovery needs.
- She says this approach has helped many women:
- regain cycles
- reduce anxiety
- improve fertility
- improve body composition
- normalize mood and energy
Birth Control, Hormone Disruption, and the Microbiome
Birth control can disrupt natural hormone signaling
- Dr. Pelz is critical of long-term hormonal birth control, saying it can:
- interrupt the body’s natural rhythm
- prevent the brain and ovaries from “learning” each other
- create issues when stopping later in life
- She also says it can harm the microbiome, which affects:
- serotonin production
- immune health
- estrogen metabolism
She frames women’s health as overly medicalized
- Her overall argument is that many women are disconnected from their body’s natural hormonal patterns.
- She believes lifestyle-based approaches can often restore more balance than relying on external hormone manipulation.
Notable Insights and Quotes
“You are more powerful than you’ve been taught.”
- One of her core beliefs is that the body is intelligent and capable of healing when given the right conditions.
“People matter.”
- She stresses the importance of community, relationships, and not isolating yourself.
“Be a lifelong learner.”
- She encourages curiosity, openness, and staying willing to update your understanding of health and the body.
Practical Takeaways
For fat loss and energy
- Don’t snack constantly.
- Aim for at least 8–10 hours without eating to access fat-burning benefits.
- Start with 12-hour fasts and build gradually.
For women
- Fast more in the first half of your cycle.
- Reduce fasting and intensity in the second half.
- Prioritize sleep, recovery, and nourishment when progesterone rises.
- Pay attention to stress, because too much stress can disrupt hormones.
For men
- Fasting can generally be more consistent.
- Still include feasting/recovery instead of constant restriction.
- Use the morning for energy and training when possible.
For everyone
- Focus on:
- sleep
- stress reduction
- food timing
- movement
- community
- Use fasting as a tool, not an identity.
Final Message from Dr. Mindy Pelz
If she could leave behind three truths, they would be:
- You are more powerful than you’ve been taught.
- People matter—surround yourself with those who support you.
- Stay curious and keep learning.
Recommended Resources Mentioned
- Book: Fast Like a Girl
- A guide to using fasting for fat loss, energy, and hormone balance
- Book: The Menopause Reset
- Focused on reducing menopause symptoms and supporting women through hormonal transitions
- YouTube: Dr. Mindy Pelz
- She encourages people to explore her videos and leave comments with questions and topics they want covered