Fasting Guide for Women by Life Stageby Dr Guy Bucci, Creator of the Centenarian Method
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The Fasting Guide for Women by Life Stage
By Dr. Guy Bucci, Nutrition Coach
Creator of the Centenarian Method
Should Women Intermittent Fast (IF)?
Occasional Fasting and Intermittent Fasting Defined:
Occasional Fasting for Cleansing & Autophagy:
This is a longer fast done periodically (e.g., once every other month or a few times a year) with the intention of supporting deep cellular repair, detoxification, and autophagy—the body’s process of cleaning out damaged cells and regenerating new ones.
Autophagy typically begins around 16-24 hours into a fast but is more significantly activated after 24–48 hours. Peak autophagy likely occurs between 36–72 hours, depending on the individual and metabolic health.
Purpose: Cellular cleanup and renewal (autophagy), Mitochondrial health, Inflammation reduction, Hormesis (stress adaptation), Metabolic reset
Frequency: Typically done occasionally (e.g., 1–6 times a year). Can be a 24-hour fast, 36-hour fast, or even multi-day fast (48–72 hrs.) under supervision
This type of fasting is safe for most people to do no matter sex or stage of life.
Intermittent Fasting (IF)
A structured eating pattern where you cycle between periods of eating and fasting daily or most days of the week. The most common method is time-restricted eating, such as eating within an 8-hour window. Usually 12–20 hours of fasting per day. Most popular version: 16:8 (16 hours fasting, 8-hour eating window)
Purpose: Blood sugar regulation, Appetite control, Weight management, Improved insulin sensitivity, Digestive efficiency, Circadian rhythm alignment
Frequency: Practiced daily or several times per week as a consistent lifestyle habit
As you will see in this guide, IF affects Women differently depending on their Life Stage and is not recommended for everyone.
1. Women in Their Reproductive Years (Approx. ages 18–40)
Consistent intermittent fasting is not recommended for women in their reproductive years, due to its potential to disrupt hormones, stress responses, and menstrual health.
What’s happening hormonally:
• High fluctuations in estrogen and progesterone
• Greater metabolic demands which means nourishing the body properly is very important
• Increased sensitivity to stress and under-nourishment
Why we avoid IF here:
• Can disrupt menstrual cycles or ovulation
• May suppress thyroid (metabolism hormone) function and raise cortisol (stress hormone)
• Increases risk of fatigue, burnout, and disordered eating patterns
• Can interfere with fertility and hormonal resilience
What to do instead:
• Eat within 30–60 minutes of waking most days (protein + fiber)
• Balance blood sugar with protein, fiber, and healthy fats
• Avoid skipping meals—nourish consistently
• Focus on nervous system regulation, digestion, and mineral-rich meals
• Practice gentle overnight fasts (12 hours max) only if it feels natural
2. Perimenopausal Women (Approx. ages 40–50)
What’s happening hormonally:
• Hormone fluctuations become less predictable
• Increased cortisol (stress hormone) sensitivity
• Insulin resistance may begin to rise
Fasting guidance:
• Consider light intermittent fasting (12–14 hours) 2–3x per week
• Never fast on high-stress or poor-sleep days
• Always break your fast with protein, fiber and whole foods
• Track energy, mood, and sleep closely to assess impact
• Fasting should be used as a tool—not a lifestyle
3. Menopausal & Post-Menopausal Women (Approx. 50+)
What’s happening hormonally:
• Estrogen and progesterone levels are consistently low
• Metabolic rate may slow
• Insulin resistance becomes more common
Fasting benefits:
• Can improve insulin sensitivity, reduce inflammation, support mental clarity
• Often better tolerated and more effective than in earlier life stages
Best practices:
• Start with a 14:10 window, then explore 16:8 if tolerated
• Fast 3–5 days per week, not daily
• Stay hydrated and include electrolytes during fasts
• Prioritize protein and resistance training to preserve lean mass
• Always listen to your body—don’t push through fatigue or stress
Final Thoughts
• Occasional fasting is a safe and healthy tool for most—but not something to force
• Consistent IF is best reserved for post-menopausal years where hormones are stable, and fasting is better tolerated
• Focus on the big levers: nervous system regulation, mineral balance, protein intake, sleep, and gut health
• Most women should typically train/workout while nourished and not in fasted state
Want Personalized Support?
The Centenarian Method helps women of all life stages regulate their nervous system, eat in alignment with their biology, and use tools like fasting only when appropriate. Apply to join the waitlist for the Centenarian Method HERE
By Dr. Guy Bucci, Nutrition Coach
Creator of the Centenarian Method
Should Women Intermittent Fast (IF)?
Occasional Fasting and Intermittent Fasting Defined:
Occasional Fasting for Cleansing & Autophagy:
This is a longer fast done periodically (e.g., once every other month or a few times a year) with the intention of supporting deep cellular repair, detoxification, and autophagy—the body’s process of cleaning out damaged cells and regenerating new ones.
Autophagy typically begins around 16-24 hours into a fast but is more significantly activated after 24–48 hours. Peak autophagy likely occurs between 36–72 hours, depending on the individual and metabolic health.
Purpose: Cellular cleanup and renewal (autophagy), Mitochondrial health, Inflammation reduction, Hormesis (stress adaptation), Metabolic reset
Frequency: Typically done occasionally (e.g., 1–6 times a year). Can be a 24-hour fast, 36-hour fast, or even multi-day fast (48–72 hrs.) under supervision
This type of fasting is safe for most people to do no matter sex or stage of life.
Intermittent Fasting (IF)
A structured eating pattern where you cycle between periods of eating and fasting daily or most days of the week. The most common method is time-restricted eating, such as eating within an 8-hour window. Usually 12–20 hours of fasting per day. Most popular version: 16:8 (16 hours fasting, 8-hour eating window)
Purpose: Blood sugar regulation, Appetite control, Weight management, Improved insulin sensitivity, Digestive efficiency, Circadian rhythm alignment
Frequency: Practiced daily or several times per week as a consistent lifestyle habit
As you will see in this guide, IF affects Women differently depending on their Life Stage and is not recommended for everyone.
1. Women in Their Reproductive Years (Approx. ages 18–40)
Consistent intermittent fasting is not recommended for women in their reproductive years, due to its potential to disrupt hormones, stress responses, and menstrual health.
What’s happening hormonally:
• High fluctuations in estrogen and progesterone
• Greater metabolic demands which means nourishing the body properly is very important
• Increased sensitivity to stress and under-nourishment
Why we avoid IF here:
• Can disrupt menstrual cycles or ovulation
• May suppress thyroid (metabolism hormone) function and raise cortisol (stress hormone)
• Increases risk of fatigue, burnout, and disordered eating patterns
• Can interfere with fertility and hormonal resilience
What to do instead:
• Eat within 30–60 minutes of waking most days (protein + fiber)
• Balance blood sugar with protein, fiber, and healthy fats
• Avoid skipping meals—nourish consistently
• Focus on nervous system regulation, digestion, and mineral-rich meals
• Practice gentle overnight fasts (12 hours max) only if it feels natural
2. Perimenopausal Women (Approx. ages 40–50)
What’s happening hormonally:
• Hormone fluctuations become less predictable
• Increased cortisol (stress hormone) sensitivity
• Insulin resistance may begin to rise
Fasting guidance:
• Consider light intermittent fasting (12–14 hours) 2–3x per week
• Never fast on high-stress or poor-sleep days
• Always break your fast with protein, fiber and whole foods
• Track energy, mood, and sleep closely to assess impact
• Fasting should be used as a tool—not a lifestyle
3. Menopausal & Post-Menopausal Women (Approx. 50+)
What’s happening hormonally:
• Estrogen and progesterone levels are consistently low
• Metabolic rate may slow
• Insulin resistance becomes more common
Fasting benefits:
• Can improve insulin sensitivity, reduce inflammation, support mental clarity
• Often better tolerated and more effective than in earlier life stages
Best practices:
• Start with a 14:10 window, then explore 16:8 if tolerated
• Fast 3–5 days per week, not daily
• Stay hydrated and include electrolytes during fasts
• Prioritize protein and resistance training to preserve lean mass
• Always listen to your body—don’t push through fatigue or stress
Final Thoughts
• Occasional fasting is a safe and healthy tool for most—but not something to force
• Consistent IF is best reserved for post-menopausal years where hormones are stable, and fasting is better tolerated
• Focus on the big levers: nervous system regulation, mineral balance, protein intake, sleep, and gut health
• Most women should typically train/workout while nourished and not in fasted state
Want Personalized Support?
The Centenarian Method helps women of all life stages regulate their nervous system, eat in alignment with their biology, and use tools like fasting only when appropriate. Apply to join the waitlist for the Centenarian Method HERE