Fasting for Women: How to Support Your Hormones, Gut Health & Metabolism the Right Way

A hormone-smart approach to intermittent fasting in perimenopause and beyond

Written By: Megan Barefoot

If there is a topic that is coming up more and more often with my clients, it’s intermittent fasting. It has become one of the most talked-about tools for weight loss, metabolic health, and longevity. But here’s the truth: women are not small men. I have been seeing this more and more in my interactions with my clients and even with men, there may need to be individual modifications needed for higher stress times and other lifestyle considerations.

While fasting can offer powerful benefits, including improved insulin sensitivity, reduced inflammation, and metabolic flexibility, it must be approached differently for women, especially in perimenopause and menopause. I highly recommend reaching out to a professional that can support you in working through your individual needs before just jumping into fasting.

When done strategically, fasting can support hormones. When done aggressively or chronically, it can disrupt them. Let’s talk about how to fast the right way.

Why Fasting Is Different for Women

Women’s bodies are hormonally dynamic. Our reproductive system is exquisitely sensitive to stress, including nutritional stress.

Fasting is, biologically speaking, a controlled stressor. (That’s right! Fasting can be interpreted as another stress on the body and if you are already overwhelmed fasting will not work the way it is intended!)

Short-term fasting can improve metabolic markers such as insulin sensitivity and fat oxidation (Anton et al., 2018). However, chronic caloric restriction or excessive fasting may elevate cortisol and disrupt reproductive hormones if not properly supported.

As Megan Ramos emphasizes in Fasting for Women, women often need a gentler, more gradual approach to fasting that prioritizes metabolic health and nourishment first (Ramos, 2021). Dr. Mindy Pelz echoes this in Fast Like a Girl, highlighting the importance of syncing fasting with the menstrual cycle rather than applying a rigid daily fasting window (Pelz, 2022).

The key message from both experts: fasting must be cyclical, strategic, and supportive. We do not want to jump into the extreme.

The Science Behind Fasting & Hormones

Research shows intermittent fasting can improve insulin sensitivity and reduce inflammation (de Cabo & Mattson, 2019). For women in perimenopause, where insulin resistance naturally increases due to hormonal shifts, this can be beneficial. in fact, I have seen this work what some might call “miracles”!

However, energy availability plays a critical role in hormone balance. Chronic energy deficiency has been linked to disruptions in the hypothalamic–pituitary–gonadal axis, which regulates reproductive hormones (Loucks & Thuma, 2003). During this pivitol time in life any disruption in that axis can make fasting feel hard….like really, really hard for little results.

In simpler terms: if the body perceives insufficient fuel over time, it may downregulate reproductive hormone production as a protective mechanism.

On top of that, cortisol, our primary stress hormone, can increase with prolonged fasting, particularly in women already experiencing high stress or poor sleep (Manoogian & Panda, 2017). Think puffy face and chubby belly when working hard to reduce fat stores.

This is why context matters.

When Fasting Can Help Women

When done appropriately, fasting may:

• Improve insulin sensitivity

• Support fat metabolism

• Reduce systemic inflammation

• Enhance metabolic flexibility

• Improve cellular repair processes

For women in perimenopause and menopause, improving insulin sensitivity can be particularly powerful. As estrogen declines, the body becomes more prone to abdominal fat storage and blood sugar fluctuations. Strategic fasting can help address this but only when paired with adequate protein, micronutrients, and resistance training.

Both Ramos and Pelz stress the importance of nourishment during eating windows. Fasting is not about eating less overall -> it’s about eating intentionally.

The Hormone Risks of Doing It Wrong

There are a number of reasons why seeking support when embarking on the fasting journey is important. Here’s where many women run into trouble.

Common mistakes include:

• Jumping straight into 18–20 hour fasts

• Fasting daily without cycling

• Undereating protein

• Fasting during high-stress periods

• Ignoring sleep disruption

In perimenopause, women are already navigating fluctuating estrogen and progesterone levels. Aggressive fasting can compound stress on the adrenal system, potentially worsening sleep, anxiety, and fatigue.

If fasting causes:

• Cold intolerance

• Hair thinning

• Sleep disruption

• Missed periods

• Increased anxiety

…it’s a sign the body may be under too much stress.

As Pelz notes, women should avoid longer fasts in the late luteal phase (the week before menstruation), when progesterone is dominant and the body requires more fuel (Pelz, 2022).

Hormone balance thrives on flexibility, not rigidity.

A Hormone-Smart Approach to Fasting

Here’s the approach I recommend at No Shoes Nutrition. It’s aligned with both the research and the wisdom of Ramos and Pelz.

1. Heal the Gut First

Before fasting, stabilize blood sugar with:

• Protein, fat, and fibre at each meal

• Adequate mineral intake

• Reduced refined sugar

• Consistent meal timing

A dysregulated gut or unstable blood sugar makes fasting feel like punishment instead of empowerment. In other words, work on your general nutrition first and only then start to modify your eating and fasting windows.

2. Start with a 12-Hour Overnight Fast

This is circadian rhythm alignment not extreme dieting. Honestly, I don’t even consider this fasting, it’s just what we all should be doing. We should be giving our gut and digestion a break for 12-hours a night to do housekeeping and empty the system.

Finish dinner by 7 pm and eat breakfast at 7 am. Seems simple but may not be easy in the beginning.

This supports:

• Insulin regulation

• Digestive rest

• Improved sleep

For many women, this alone improves energy and weight regulation.

3. Build to 14–16 Hours (If Appropriate)

Only extend fasting if:

• Sleep is stable

• Stress is manageable

• Protein intake is sufficient

• Strength training is included

Women over 40 especially need to protect muscle mass. Protein is non-negotiable. I know there is a LOT of pressure out there to get enough protein. Focus on getting a serving of protein the size and thickness of the palm of your hand at each meal and leave it at that. No need to over do it!

4. Cycle Your Fasts

If menstruating:

• Follicular phase (after period): longer fasts tolerated

• Ovulation window: moderate fasting

• Luteal phase (week before period): shorten fasts

If in perimenopause:

• Flexibility is key

• Some weeks tolerate fasting well

• Other weeks require more nourishment

Rigid daily 18-hour fasting is rarely ideal long-term for hormonally sensitive women.

Fasting in Perimenopause & Menopause

This is where nuance matters most. There is a lot going on for women in this period of their life and learning to listen to your body’s signs and symptoms is important.

As estrogen declines, women often experience:

• Increased insulin resistance

• Weight gain around the abdomen

• Sleep disturbances

• Muscle loss

Strategic intermittent fasting can help improve insulin sensitivity and reduce visceral fat (de Cabo & Mattson, 2019). However, muscle preservation becomes critical.

This means:

• Prioritize 25–35g of protein per meal

• Incorporate resistance training (lift heavy things)

• Avoid chronic calorie restriction (eat heartily when you are in your eating window!)

• Use fasting as a tool, not a lifestyle identity

Fasting works best when paired with strength, nourishment, and stress management. When you aren’t eating for long periods it means that when you are eating it’s important to prioritize nurtient dense whole foods more than ever!

Fasting Is a Tool — Not a Punishment

Both Fasting for Women and Fast Like a Girl emphasize personalization. There is no universal fasting schedule that works for every woman. It’s a very interesting feeling to look forward to NOT eating as much as you look forward to eating delicious foods!

Your hormones are responsive. They are intelligent. They are protective.

If fasting improves:

• Energy

• Mental clarity

• Body composition

• Blood sugar stability

…it may be supportive.

If fasting worsens:

• Sleep

• Anxiety

• Hair health

• Menstrual regularity

…it may be too aggressive.

The goal is metabolic flexibility, not metabolic stress.

The Bottom Line

Fasting can be a powerful strategy for women, especially in perimenopause and menopause, when done strategically.

But hormone health requires:

• Adequate protein

• Balanced blood sugar

• Gut support

• Stress regulation

• Strength training

Fasting is not about eating less. It’s about creating space for your body to reset while still deeply nourishing it. If this feels overwhelming or just not for you then that’s perfectly okay! This is just one option out there that works for some people.

Ready to Fast the Right Way?

If you’re navigating perimenopause or menopause and want to use fasting to support your hormones, without disrupting them, our September Gut-Hormone Program was designed for you.

Inside, we combine:

• Hormone-aware fasting

• Gut restoration

• Blood sugar balancing

• Strength-focused nutrition

• Sustainable lifestyle strategies

Spots are limited. Or, if you prefer individualized support, book a FREE consultation at www.noshoesnutrition.com and let’s create a plan tailored to your body. Because the path to health is paved with good intestines and smart hormones.

---

References

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

de Cabo, R., & Mattson, M. P. (2019). Effects of intermittent fasting on health, aging, and disease. New England Journal of Medicine, 381, 2541–2551. https://doi.org/10.1056/NEJMra1905136

Loucks, A. B., & Thuma, J. R. (2003). Luteinizing hormone pulsatility is disrupted at a threshold of energy availability. Journal of Clinical Endocrinology & Metabolism, 88(1), 297–311. https://doi.org/10.1210/jc.2002-020369

Pelz, M. (2022). Fast Like a Girl. Hay House.

Ramos, M. (2021). Fasting for Women. Victory Belt Publishing.