Most fasting advice stops at 16 hours. But what if the real benefits don’t even start until after that?

For women in midlife, short-term fasting can be a great entry point—but it’s not where the deepest shifts happen.

If you’ve ever felt like you’re doing everything “right” and still stuck in the same cycles of fatigue, cravings, and belly weight… you’re not imagining it. Because while a 16-hour fast may tap you into mild ketosis, the real cellular clean-up, hormone recalibration, and metabolic magic tends to begin closer to the 36-hour mark.

That’s when your body begins activating longer-term healing responses—triggering processes like autophagy (your internal spring cleaning), insulin reset, and deeper immune repair.

Whether you’re navigating perimenopause, postmenopause, or just feeling off-rhythm in your 40s and 50s, fasting—done wisely—can offer profound benefits.

In this guide to safe extended fasting for women in midlife, we’ll break down exactly what happens after hour 24, why it matters for hormone health, and how to explore a longer fast in a way that supports—not stresses—your body.

What the Science Says About Fasting Beyond 24 Hours

If you’ve been curious about going beyond your usual intermittent fasting window, here’s the exciting part: the deeper health benefits of fasting tend to ramp up—not taper off—once you pass the 24–36 hour mark.

Let’s break down what actually happens in your body—and why this matters especially for women in midlife.

Autophagy: Cellular Spring Cleaning

Autophagy—the body’s natural process of cleaning up damaged cells—begins around the 17-hour mark of a fast for many women, especially those who are metabolically adapted. But the longer you stay fasted, the more deeply this process unfolds.

Around 24 to 36 hours in, autophagy intensifies, promoting deeper immune support, inflammation reduction, and cellular renewal.

For women in perimenopause and postmenopause—when oxidative stress and cellular ageing can accelerate—supporting this natural detox pathway can have a powerful impact on how you feel physically, mentally, and hormonally.

Citation: Mizushima, N., & Komatsu, M. (2011). Autophagy: Renovation of Cells and Tissues. Cell, 147(4), 728–741. [https://doi.org/10.1016/j.cell.2011.10.026]

Ketosis: A Cleaner Energy Source

By this stage in your fast, your glycogen stores have dropped significantly and your body shifts into ketosis—burning fat for fuel and producing ketones. These ketones cross the blood-brain barrier and offer a more stable, clean energy source that many women describe as increased mental clarity, focus, and emotional steadiness.

Ketosis can begin as early as 13 hours into a fast, especially if you’re already metabolically flexible. But with a 36-hour fast, you’re not just reaching ketosis—you’re staying in it long enough to experience a deeper shift in energy, cognition, and hormone balance.

Immune Reset and Inflammation Reduction

Emerging research shows that longer fasts can influence the immune system in powerful ways—including the regeneration of white blood cells and reduced pro-inflammatory cytokines.

While immune cell regeneration is typically associated with 48–72 hour fasts, even shorter prolonged fasts (around 36 hours) have been shown to lower systemic inflammation and improve immune modulation—important factors for women over 40 experiencing joint pain, fatigue, or autoimmune flares.

Citation: Longo, V. D., & Panda, S. (2016). Fasting, Circadian Rhythms, and Time-Restricted Feeding in Healthy Lifespan. Cell Metabolism, 23(6), 1048–1059. [https://doi.org/10.1016/j.cmet.2016.06.001]

Metabolic Recalibration

A longer fast allows for sustained periods of low insulin and stable blood sugar, encouraging your body to become more metabolically flexible—the ability to switch efficiently between burning glucose and fat.

For midlife women navigating insulin resistance, stubborn belly fat, or reactive blood sugar spikes, this recalibration is essential. It’s not about weight loss at any cost—it’s about giving your body a chance to reset, without the hormonal chaos triggered by constant snacking or sugar crashes.

Citation: Anton, S. D., et al. (2018). Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting. Obesity, 26(2), 254–268. [https://doi.org/10.1002/oby.22065]

So, Is It Worth Going Beyond 24 Hours?

In short: yes—if you do it safely, intentionally, and with the right support.

For women in perimenopause and postmenopause, the benefits of a longer fast aren’t just theoretical—they’re deeply practical. From reducing inflammation and supporting metabolism to improving cognitive function and energy levels, these changes can help realign your body’s natural rhythms at a time when everything feels in flux.

Let’s take a closer look at why these shifts are especially powerful for women 40 and beyond—and how to approach them without overwhelming your system.

Why This Matters for Women 40+

There’s a lot of generic fasting advice out there—but most of it doesn’t take into account the hormonal shifts, metabolic changes, and nervous system demands of women in midlife. Especially during perimenopause and postmenopause, what worked in your 20s or 30s might not feel supportive anymore.

That’s why understanding the unique benefits of a longer fast—specifically for women 40+—is so important.

1. A Deeper Reset for a Different Season of Life

If you’ve ever tried intermittent fasting—like the popular 16:8 approach (16 hours fasting, 8-hour eating window)—and thought, “I don’t really feel that different,” you’re not alone.

While shorter fasts can help reduce snacking and create structure, they don’t always trigger the deeper metabolic and cellular shifts your body may need in midlife.

That’s where a 36-hour fast can offer more:

• More time in autophagy, where your body clears out damaged cells and makes space for renewal
• Longer exposure to ketosis, which supports steady energy, focus, and hormone balance
• A deeper drop in insulin and inflammation, both of which often become disrupted in midlife

Think of it this way:

Short fasts manage the surface symptoms. Longer fasts help reset the root.

2. Supporting Hormone Balance in Perimenopause and Menopause

Extended fasting (done wisely) can help stabilise blood sugar, lower insulin resistance, and reduce inflammation—all of which are key players in hormone health.

As estrogen levels decline, many women become more sensitive to blood sugar swings and chronic stress. A well-supported fast can help retrain the body to burn fat for fuel, reduce cortisol spikes, and give your hormones a break from constant digestive and metabolic demands.

That doesn’t mean longer fasts are a fix-all—but they can be a useful tool in your midlife wellness toolkit.

3. Mental Clarity, Motivation, and Mood

Midlife often brings a mental load that’s hard to describe: brain fog, irritability, feeling “off” for no obvious reason. Ketones produced during extended fasting are known to support cognitive function and mood stability—especially when combined with rest and hydration.

You might notice:

• Clearer thinking
• Less anxious urgency
• Improved focus and calm
• A renewed sense of self-trust around your body

These shifts matter. Because how you feel—emotionally, cognitively, energetically—shapes every other part of your health journey.

Safety First: How to Approach Longer Fasts Wisely

Fasting beyond 24 hours isn’t something you should jump into without preparation—especially during perimenopause or postmenopause, when your body is already navigating major hormonal shifts.

That doesn’t mean it’s dangerous. It just means it deserves the same respect and care you’d give any other powerful wellness tool.

Here’s how to approach it wisely.

1. Start Where You Are

If your longest fast so far has been 14 or 16 hours, don’t leap straight to 36. Build up slowly, over time.

Try this progression:

• Begin with 14–16 hours a few days per week
• Gradually increase to 18–24 hour fasts once your body adjusts
• Add in a supported 36-hour fast occasionally, with clear intention

This approach supports your nervous system, energy, and blood sugar stability—especially important for midlife women, who may be more sensitive to stress.

2. Prioritise Hydration and Electrolytes

Going without food doesn’t mean going without support. During longer fasts, hydration is essential—not just for comfort, but for safety.

Key tips:

• Drink plenty of water, ideally with added minerals
• Consider a pinch of sea salt or LMNT-style electrolyte support
• Avoid diuretics (like excess coffee or alcohol) before and during your fast

Proper hydration helps prevent dizziness, headaches, and blood pressure drops—common reasons people struggle with extended fasts.

3. Break the Fast Gently

Your first meal matters. Don’t jump straight to a carb-heavy or high-sugar plate.

Instead, break your fast with:

• A small portion of protein and healthy fat (like eggs or broth with olive oil)
• A few gentle veggies (steamed or sautéed)
• Light movement or rest afterward, not a high-intensity workout

Think: nourishment over reward. The goal is to ease your body back into digestion, not shock it.

4. Know When to Avoid Longer Fasts

Extended fasting isn’t right for everyone—and that’s okay.

Skip or modify longer fasts if you:

• Are under chronic or acute stress
• Struggle with disordered eating or food anxiety
• Have thyroid or adrenal issues that aren’t well managed
• Are pregnant, breastfeeding, or recently postpartum
• Feel more exhausted, moody, or dizzy during fasting

Fasting is meant to support your energy—not deplete it. If your body’s giving you signals that it’s too much, listen.

(If you’re unsure, always check in with a qualified health practitioner or book a free Insight Call to talk it through.)

How to Try a Safe 36+ Hour Fast

If you’re curious to experience the deeper benefits of a longer fast, the key is to prepare intentionally—physically, mentally, and emotionally.

Here’s a step-by-step guide to help you try your first 36+ hour fast in a way that feels supported and sustainable.

1. Set Your Intention and Choose the Right Window

The most successful fasts start with a clear why.

Do you want to reset your eating habits? Support your immune system? Break through a plateau? Choose one core goal and write it down.

Then, choose a low-stress window. Many women in midlife find weekends or quiet weekdays ideal for their first longer fast—especially if they don’t have intense social or work obligations.

Example schedule:

• Last meal: Friday 6pm
• Break fast: Sunday 6am (36 hours)

2. Prepare the Body in Advance

Don’t go into an extended fast straight from late-night snacking or high-carb meals.

In the 1–2 days before your fast:

• Focus on protein, healthy fats, and non-starchy veg
• Skip alcohol and reduce caffeine
• Get extra sleep if possible
• Stay hydrated and ensure electrolyte balance is already solid

This helps you enter the fast with stable blood sugar and a calmer nervous system.

3. Supportive Habits During the Fast

Think of this as a time for stillness, clarity, and nourishment—just not from food.

Key practices:

• Sip warm herbal teas, filtered water, or electrolytes throughout the day
• Schedule in rest: light walks, reading, journaling, or gentle stretching
• Avoid high-output tasks like intense exercise or big decision-making
• Keep your calendar light where possible

Most women find hunger peaks in waves, not continuously. When it hits, take deep breaths, drink water, and remind yourself of your intention. Then… it usually passes.

4. Breaking the Fast with Care

When you reach your chosen fast-breaking time, don’t rush. Pause and tune in.

Break your fast gently with:

• A small portion of bone broth, scrambled eggs, or avocado with olive oil
• A light meal 60–90 minutes later with protein, fat, and fibre
• Space and rest to digest—avoid intense movement straight after

Resist the urge to overcompensate. It’s not about “making up” for the fast—it’s about re-entry with kindness.

5. Track and Reflect

After the fast, take note of how you feel:

• Energy levels
• Bloating or digestion
• Mood and focus
• Sleep and cravings

This feedback will help you decide if a 36-hour fast suits you—and how often it might be beneficial to repeat.

For some women, it becomes a monthly or quarterly reset. For others, it’s a one-time experience that builds confidence and insight.

Alternatives & Options: Finding What Works for You

Not everyone is ready—or suited—for a full 36-hour fast. And that’s okay.

What matters most is finding a rhythm that honours your body, your hormones, and your season of life.

If you’re not sure where to begin, here are some thoughtful alternatives that still offer many of the benefits of fasting without requiring a full extended fast:

Fasting Mimicking Diet (FMD)

The Fasting Mimicking Diet is gaining popularity for good reason—especially among women in perimenopause and menopause.

It’s a 5-day low-calorie, high-fat protocol that mimics the effects of fasting without requiring you to stop eating entirely. Research shows it can activate autophagy, support metabolic health, and help with inflammation—all while providing nutrients that reduce the stress of a full fast.

ProLon is the most well-known version, but some women prefer to make their own simplified version with guidance.

This option is ideal if:

• You want the cellular reset benefits of fasting
• You feel better with food-based support
• You’re managing thyroid, adrenal, or nervous system needs

Daily Fasting Rhythms

If longer fasts feel too extreme, even a gentle rhythm of time-restricted eating can make a difference.

Start with:

• A 12:12 window (eat for 12 hours, fast for 12 hours)
• Work gradually towards 14:10 or 16:8, only if it feels good

This daily rhythm helps:

• Support blood sugar regulation
• Improve digestion
• Create more structure and clarity around meals (vs. all-day snacking)

Remember: you don’t need to fast every day to see benefits. Rhythm and consistency matter more than perfection.

Gentle Reset Days

For those who need flexibility or are recovering from burnout, gentle reset days are a nourishing alternative.

Once or twice a month:

• Eat simple, anti-inflammatory meals
• Hydrate generously
• Prioritise rest, sleep, and light movement

This approach removes pressure and allows the nervous system to settle—while still offering hormonal and metabolic support.

Every woman is different. What works beautifully for one person may not serve another.

That’s why personalized fasting guidance for women in midlife is so important. Your hormones, history, and health needs deserve a plan that’s tailored—not copied.

Your Midlife Action Steps

If the idea of a 36-hour fast sparked curiosity—or maybe a little resistance—you’re not alone.

What matters most is this: you now have a clearer understanding of what’s happening in your body, how fasting fits into it, and what options are available.

Whether you’re ready to try a longer fast or you simply want to feel more in control of your energy, hormones, and rhythm—here’s how to get started.

Midlife Fasting Prep Checklist

Before you begin:

• Hydrate intentionally the day before with water, electrolytes, and mineral-rich broth
• Eat nourishing, protein-rich meals leading up to your fast to stabilise blood sugar
• Choose a stress-minimal window—weekends or quieter days work well
• Prepare for rest, not productivity—your body is doing deep internal work
• Plan how you’ll break your fast (e.g., bone broth, gently cooked veggies, protein)

During your fast:

• Keep moving gently: short walks, light stretching, yoga
• Drink plenty of water and electrolytes
• Listen to your body. Fatigue, dizziness, or irritability are signs to pause and reassess

After your fast:

• Break it slowly with nourishing, easy-to-digest foods
• Avoid sugar, alcohol, or processed carbs for at least 12 hours
• Reflect on how you feel—mentally, physically, and emotionally

The real magic of fasting in midlife lies in choosing a rhythm that honours your body—not in chasing extremes. Whether you fast for 12 or 36 hours, the goal is the same: to feel more balanced, more energised, and more in tune with your natural cycles.

⚠️ A gentle note: If you’re navigating high stress, pregnancy, postpartum, or ongoing health conditions, longer fasts may not be right for you right now. Honour where you’re at—or speak to a qualified practitioner for personalised guidance.

Ready for Personalized Support?

Every woman’s body is different—and your fasting practice should reflect that.

If you’re wondering whether a longer fast is right for you, or you’d like to explore how to reset your rhythm without extreme rules…

Book a free Insight Call. We’ll look at your energy, hormones, mindset, and goals—and explore what a supportive, sustainable fasting plan could look like for you.

You don’t need to push through. You just need to find what fits—and that’s what I’m here for.

The content provided in this post is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this post.