How to Fast According to Your Menstrual Cycle
- Wellness Effect
- Jul 23, 2024
- 4 min read
Intermittent fasting has been a popular trend in recent years, offering numerous health benefits from weight loss to improved metabolic health. However, when it comes to women, especially those who menstruate, it's crucial to tailor fasting to our unique physiological needs. Cycle fasting aligns fasting patterns with the menstrual cycle. I started practicing this in order to help regulate my periods, after coming off oral contraception in 2023. Read on to find out how it works!
Understanding Cycle Fasting
Cycle fasting is an intermittent fasting approach that takes into account the different phases of the menstrual cycle. The menstrual cycle typically has four phases, the timings of these can change per individual:
1. Menstrual Phase (1-5): The beginning of the cycle when menstruation occurs.
2. Follicular Phase (6-14): Leading up to ovulation, where the body prepares for a potential pregnancy.
3. Ovulatory Phase (15-17): Around the time of ovulation.
4. Luteal Phase (18-28): Post-ovulation, when the body either prepares for pregnancy or the next menstrual cycle.
The Science Behind Cycle Fasting
The hormonal fluctuations during the menstrual cycle significantly impact metabolism, appetite, and energy levels. When you fast according to your menstrual cycle, women can potentially maximise benefits and minimise adverse effects. I highly recommend reading Fast Like a Girl by Dr Mindy Pelz to full understand the science behind fasting.
The fasting cycle that Dr Mindy suggests differs slightly from the typical menstrual cycle detailed above. I've included it here but when I first came off hormonal contraception I had to follow a reset plan, which I've detailed further down in this blog. It's also important to note that there's a lot of debate about whether women should skip breakfast. I personally prefer to miss dinner and eat breakfast, to help regulate the cortisol spike that happens in the morning when we wake.
How to Fast According to Your Menstrual Cycle
Days 1-10
This might surprise you as we tend to think we need to eat more when we have our periods but actually this is a great time to fast. Our hormones are lower at this time so we can feel more emotionally stable, have more energy and are less hungry.
Suggested fasting lengths: 13-72 hours
Suggested diet: healthy fat and protein, reduce starchy carbs, fruit, veg, fermented foods.
Days 11-15
Coming up to ovulation is the part of your cycle where you'll feel at your best. Oestrogen is peaking and testosterone is rising, giving you more energy, motivation and libido. You'll be feeling prettier and more confident. At this point we need to focus more on metabolising the hormones than producing them. Hormones need to be broken down for use and excretion so we need to nurture our livers and guts at this time to help with this process.
Suggested fasting lengths: up to 15 hours
Suggested diet: fats, protein, cruciferous vegetable, bitter leaves, sesame and flaxseeds, fermented foods, dandelion tea.
Days 16-19
Your hormones have just surged for ovulation and are now on a downward turn. This is a great short window to fast to improve cell autophagy (breakdown and recycle of old cells) and mental clarity, among other things. Longer fasts are great in this time and it's when I'll do a 24-36 hour fast.
Suggested fasting lengths: 13-72 hours
Suggested diet: healthy fat and protein, reduce starchy carbs, fruit, veg, fermented foods.
Days 20 - bleed
This is your time to focus on your own self-care. We need progesterone to rise to help the womb shed its lining. Stress can impact progesterone in a negative way so this is your time to chill out, get more sleep and put yourself first. Reduce fasting, do gentler forms of exercise like yoga and walking and increase carbohydrates in your diet.
Suggested fasting length: None
Suggested diet: same as days 11-15 and add starchy foods like russet potatoes, sweet potatoes, legumes, citrus and tropical fruits, rice, pumpkin seeds.
Benefits of Cycle Fasting
1. Hormone Balance: Aligning fasting with the menstrual cycle can support hormonal balance, potentially reducing PMS symptoms and improving menstrual regularity.
2. Enhanced Metabolic Health: Cycle fasting can improve insulin sensitivity and metabolic flexibility, making it easier to maintain a healthy weight and reduce the risk of metabolic diseases.
3. Improved Energy Levels: By tailoring fasting windows to the body’s natural rhythm, women can experience steadier energy levels and reduced fatigue.
4. Mental Clarity: Many women report improved mental clarity and focus when fasting, especially during the follicular phase when oestrogen levels peak.
Considerations and Tips
1. Listen to Your Body: Every woman’s cycle and response to fasting can vary. It's essential to pay attention to hunger cues, energy levels, and overall well-being.
2. Stay Hydrated: Proper hydration is crucial, especially during fasting periods. Water, herbal teas, bone broth and electrolyte-rich drinks can help maintain hydration.
3. Nutrient-Dense Diet: Focus on whole, nutrient-dense foods to ensure you’re getting the necessary vitamins and minerals.
4. Consult a Professional: Before starting any fasting regimen, it's advisable to consult with a healthcare provider, especially for women with underlying health conditions or those who are pregnant or breastfeeding.
Fasting Reset
I thought that when I came off hormonal contraception that I'd immediately go back to having a regular menstrual cycle. I was so wrong! My cycle was fluctuating between 18 and 40 days which made following the fasting cycle above difficult as I wasn't sure what point in my cycle I was at. So I followed this simple fasting reset for a few months and my menstrual cycle quickly regulated.
Days 1-10
Suggested fasting lengths:
Days 1-4: 13 hours
Day 5: 15 hours
Days 6-10: 17 hours
Days 11-15
Suggested fasting lengths: 13 hours
Days 16-19
Suggested fasting lengths: 15 hours
Days 20 - bleed
Suggested fasting length: None
Hopefully this simple breakdown of cycle fasting is helpful. If so, please share with a friend. I'd love to hear more about your experiences of fasting in the comments.
Very interesting