If you’re a woman in your early 40s, you may have noticed a change in your monthly cycle.
Maybe your cycle has gotten a few days longer or shorter, or you’ve experienced a major shift in how you feel throughout the month.
This is a perfectly normal part of aging. It’s called perimenopause: the very earliest stage of menopause, when your hormones first begin to shift. You still have quite a few years before true menopause begins—but hormone changes are challenging, and for many women, perimenopause can be a scary time. The good news is that there’s a lot you can do to support your body during perimenopause. One of my favorite tools is intermittent fasting. It’s a simple, effective way to balance your hormones and ease the side effects of perimenopause.
Here’s a closer look at perimenopause and how intermittent fasting can help you navigate the shifts perimenopause brings.
Perimenopause is a natural, healthy part of aging.
Dr Mindy Pelz
What Is Perimenopause?
Perimenopause (also called the menopause transition) marks the beginning of your body’s transition into menopause. It can happen as early as 35 or as late as 50, but for most women, perimenopause begins around age 40-44.
During perimenopause, your ovaries start making less estrogen and progesterone. As a result, your menstrual cycle will become irregular. It may lengthen at times, shorten at others, or even stop entirely for a few months.
Perimenopause is a natural, healthy part of aging. However, it can be a challenging time for a lot of women. It’s important to understand what to expect during perimenopause, and what you can do to make it easier.
Symptoms of Perimenopause
During perimenopause, you may occasionally experience symptoms of low estrogen and progesterone, including[*]:
Changes in libido
If you’re reading this and panicking, DON’T WORRY! Your body’s needs are changing, and it’s perfectly normal to feel anxiety.
But there’s a lot you can do to support your hormones during your perimenopausal years.
What Is Intermittent Fasting?
I’ve worked with hundreds of perimenopausal clients over the years, and from what I’ve seen, intermittent fasting has been the single most effective tool for managing perimenopause symptoms.
Intermittent fasting is simple: it involves going without food for a portion of the day and then having all your meals within a shortened eating window. That’s it—you need to change when you eat.
For example, you may do a 16:8 fast, which is when you fast for 16 hours and eat in an 8-hour window (say, between 12-8 PM each day).
Or you could do One Meal A Day (OMAD) fasting, which is when you only eat one big meal (a lot of people choose dinner) and then fast the rest of the day.
Some people like to do 48-hour fasts, while others keep things shorter at around 14 hours. That’s the low end, but generally speaking, anything above 14 hours without food is considered a fast. The length depends on what feels good for you.
Benefits of Fasting
Fasting is great for you in about a dozen different ways. I cover them in depth in my new book, Fast Like A Girl, but here’s a quick rundown of a few of the benefits of intermittent fasting.
Blood pressure, cholesterol, and blood sugar levels[*]
Intermittent fasting can also help you balance your hormones, depending on when and how you fast.
How Fasting Can Help with Perimenopause
During perimenopause, your hormones start to change. Your estrogen goes on a rollercoaster—high one day, low the next—while your progesterone steadily declines over time.
Fasting can help support your body and bring balance during these hormonal changes, especially if you time your fasting with your menstrual cycle.
Here’s my strategy for fasting during perimenopause. Your cycle starts at day 1, which is the day you get your period.
Days 1-10: Building Estrogen with Longer Fasts
The beginning of your cycle is an estrogen-building phase, which is the perfect time to fast.
Estrogen does really well with longer fasts, so during days 1-10, focus on 20 hours or more fasts. If you’re up for it, maybe add a 36-hour or 48-hour fast.
These longer fasts will decrease inflammation[*] and keep you feeling mentally and physically strong, which is perfect as you go into the next phase of your cycle.
Days 11-15: Supporting Ovulation with Shorter Fasts
Ovulation starts around the middle of your cycle. If you’re perimenopausal then estrogen is at its peak during this time, and progesterone begins to increase slightly.
For days 11-15, you can still get all the anti-inflammatory and energy-enhancing benefits of fasting, but you’ll want to keep fasts shorter—no more than 15 hours per day.
Progesterone makes it difficult to fast, and as it rises toward day 15, you may find fasting feels harder and makes you cranky. If that happens, listen to your body and ease off.
Day 16-19: Longer Fasts
You have one more little energy phase of your cycle during days 16-19. Your hormones dip again, which makes longer fasts easy. Get another 24-hour fast-in during this time if you can.
You want to build up lots of energy and decrease inflammation to an all-time low as you prepare to enter the last phase of your cycle.
Day 20-End: Feasting to Nourish Your Body
During the final phase of your cycle, progesterone arrives in a big way. It increases until your next cycle begins, bringing along with it bloating, cramps, fatigue, and all the other symptoms that can make this time hard on you.
However, after all the fasting you’ve done in the earlier part of the month, your inflammation will be low and you’ll feel much better during this phase of your cycle. Now is the time to rest and take care of yourself.
From day 20 until your period, avoid fasting and focus on eating nourishing whole foods like sweet potatoes, butternut squash, healthy fats like grass-fed butter and olive oil, red meat, fatty fish, green vegetables, and plenty of fruit.
Pairing your cycle with fasting in this way can help keep your hormones more predictable during perimenopause and can prime your body better to handle the occasional sudden shift in estrogen or progesterone.
So many of my clients have benefitted from this kind of fasting. If you’re struggling with perimenopause, give fasting a try. You may be amazed by the difference it makes.
Perimenopause can be a challenging time, but with the right lifestyle changes, you can manage it with grace and embrace your transition into a new phase of life.
If you’re struggling with a shift in your hormones, changes to your cycle, or symptoms of perimenopause, give intermittent fasting a try. It can be a transformative tool for balancing your estrogen and progesterone and working with your body’s natural rhythms.
And if you want to learn more about managing perimenopause, I have a wealth of free resources available for you. Check out my Menopause Survival Guide or my 30-Day Ketobiotic Reset—both are amazing (and free!) ways to support your body and mind during one of the biggest biological shifts of your life.