A Women's Guide to Intermittent Fasting with Dr Mindy Pelz

Dr Mindy Pelz is a pioneer in the fasting movement and author of The Menopause Reset, The Reset Factor, and The Reset Kitchen. Learn about fasting and how women should customize it based on their cycle and life stage.

Georgie Kovacs: What is intermittent fasting?


Dr Mindy Pelz

We have two energy systems

  1. Sugar burner: What you access when you are eating.

  2. Fat burner: We tap into something called ketones and ketones like make us limitless they give us this insane mental capability this insane energetic capability you are now burning energy from fat.

With intermittent fasting, which there are many types, but let’s assume you fast for 13 to 15 hours. By doing this, you are training your body to operate as a fat burner. Then you eat and switch to a sugar burner phase. Alternating between the two is called metabolic switching.


Georgie Kovacs: How does one transition into intermittent fasting?

Dr Mindy Pelz: The trick is to stabilize your blood sugar. A way to start is to remove the refined carbohydrates and sugars, along with eating the right oils. Once your blood sugar is more stable, you can add on 13 to 15 hours of fasting.


Admittedly, fasting has become this hot trend. Unfortunately, a lot of people think they can fast for 17 hours, 24 hours, or whatever they decide but then outside of that, they choose to eat whatever they desire. This is called a dirty fast. I don’t advocate for dirty fasting because it is almost as if you are oscillating between healing the body and building disease.


What I do advocate for is incorporating fasting into a healthy diet. This is not about debating whether you are vegan or carnivore, as an example. It is about eating healthy and adding the fasting phase.


Georgie Kovacs: Why do you think we as humans tend to profess “our diet is best?”

Dr Mindy Pelz I've been teaching fasting on these public platforms, and we see all these food debates going on. People are really zealots for whatever food combination is working for them. And I really want to encourage people to find the path that works for them

There's a new concept in functional medicine that's emerging, which I love - it's called n of one. What this means is that you are your own research study. So your path and my path will look completely different. However, there are certain principles we should all follow.


  • We're made to tap into the fat burner energy source.

  • We are not made to eat chemicals.

  • “You be you” when it comes to the diet of your choice. (As long as it is healthy, of course!)


Why do we grab onto these diets, and then just want to make all of our friends believe it? I think part of that is human nature, especially as women. One of the theories with women in general is that we have a hormonal hierarchy, where at the top of the hierarchy is oxytocin. This is when we get good bursts of oxytocin through great conversations, like this one, and hanging out with other women. Then we regulate all the other hormones. As women, I think we don't even realize it, but we are hormonally driven to want to share something that we're passionate about, especially with other women.

Georgie Kovacs: What are the benefits of intermittent fasting?

Dr Mindy Pelz:

The most popular meta analysis that we have, and it was printed in the New England Journal of Medicine in December 2019, where they reviewed 1,500 different peer reviewed journals. It is suggested that, based on human and animal studies, intermittent fasting seems to help those with:

  • Obesity and Diabetes

  • Cardiovascular Disease

  • Certain Cancers

  • Neurodegenerative Disorders

  • Asthma

  • Multiple Sclerosis

  • Arthritis

  • Surgical and Ischemic Tissue Injury


Through intermittent fasting, you become more insulin sensitive and create something called ketones. Your brain will live off of glucose and ketones. When you get this rush of ketones through fasting, the brain gobbles up those ketones, and it uses them to heal neurons. Neurons are like messenger highways in the brain that transmit information, and it heals those highways so that you can think clearer. This is why it is hypothesized to be good for Alzheimer's and dementia - your memory is better, your longevity increases.


So we can see a chemical change, specifically growth hormone, which you need to make testosterone. So it's like a chemical reaction that is shifting and allowing your body to go into this accelerated healing state. This is why to me 13 to 15 hours, like everybody should be doing it. And then just tack on your regular, healthy diet.

Georgie Kovacs: You mentioned ketones. Should one drink ketones, and is this safe?

Dr Mindy Pelz: This is called exogenous ketones. When fasting became a trend, there were several companies that developed exogenous ketones given the known benefit of ketones.


This is not necessarily healthy, and this is why. Ketones show up when the blood sugar goes down and then that creates a signal to the liver to make ketones. This is what happens during fasting. So if I put ketones in from the outside, and my blood sugar is still high, we have no research on what that will do to the human body. That is going against the design of our own body, so that, alone, makes me very nervous.


The second thing that I'll say is that we know that ketones are a sign that you're burning fat. If you put it in from the outside, it doesn't mean the ketone is going to burn the fat. The ketone is what signals you are burning fat. Do you see the difference there? So it's totally against the intelligence of the body.


However, there is a place for exogenous ketones, because we know they are very reparative to the brain. Considerations include:

  • People who go on long fasts, such as a three-day water fast.

  • Alzheimer’s patients

  • Autistic children

  • Children with learning disabilities

We can take exogenous ketones and then make sure we're not giving it to them after a big meal. We want their blood sugar to be pretty stable, and then give them some ketones so that those ketones can heal. That's where you could use it sensibly.

Georgie Kovacs: How can women incorporate intermittent fasting and why is it different from me?

Dr Mindy Pelz: I categorize women into three different age groups under 40, 40 to 55, and then over 55. Let’s break down how each group should customize intermittent fasting. Granted, they should also customize what is appropriate for them, but these are suggestions for those whose bodies behave in a way that is typical for their age group.


Women in their Reproductive Years

If you're under 40, you need to map your fast according to your menstrual cycle. Let’s assume you have a normal 28 to 35 day normal cycle and the day you bleed is day one. From day one to day 10. Your body is making estrogen. The closer you get to day 10, towards ovulation, the more estrogen you need. There are two things you need to make estrogen. You need a healthy brain where your hypothalamus and pituitary are healthy. You also need to be insulin sensitive.


Approximately day 11 to day 15 is the ovulation window, which I like to call your superpower phase. Estrogen, progesterone, and testosterone are all at play. You don't want to fast a lot then. You've already produced the hormones, so intermittent fasting is as far as you should go.

In order to use estrogen, you must have a healthy gut, so we recommend you do more of the polyphenol, probiotic, and prebiotic foods. If you know the carnivore diet works for you, you would do it during that time, but I don't have women fast longer than 15 hours in that little window.


As you come out of ovulation, if you're not trying to get pregnant and you have a normal, there's another four-day period where you can fast all you want, you could probably eat whatever you want from about day16 till about day 19. Around this time, your body starts to produce progesterone. This means no stress on the body - which includes no marathons, no fasting. You shouldn’t even do CrossFit. Instead, focus on nurturing yourself. If you really want to fast, no more than 13 hours.


Once you bleed again, you can go back to the fasting schedule I just outlined.


Note that some articles indicate that women should not fast. However, what is not taken into account is the nuance of when a woman should or should not fast.


Women in Perimenopause (~40-55)

This is a tough time. We don't know if our cycles are coming or going. So the first thing I tell women over 40 is to start mapping your cycle

We have to remember that from 40 to about 55, women’s ovaries are slowly winding down. In that winding down, they have to hand over the production of sex hormones to another organ. So your ovaries make estrogen, progesterone, testosterone, and at this age, to put it simply, they hand it over to your adrenal glands. This is why if you are a stressed out 40 year old 43 year old, which is what I was, you experience symptoms like hot flashes.


Yes, I was stressed out 43-year old. What you used to be able to get away with stress at 33, you will not get away with at 43 and 45, because your adrenals are not only making epinephrine, norepinephrine and cortisol, but now they have to make estrogen, progesterone, and testosterone. So if you don't mind those adrenals, then those sex hormones get out of whack, and now you have a hot flash, you're not sleeping, you're anxious and irritable.


What fasting does for those over 40 is you're balancing stress for the human body, you are balancing insulin, which also controls those sex hormones.


And you've taken one of the major stressors off of the plate, and now your body can produce those hormones.

Thus, in addition to mapping your cycle, women at this age really need to:

  • Work on your diet

  • Optimize your microbiome

  • Remove toxins

  • Slow down - avoid the “rushing woman syndrome”


If you incorporate these principles, your peri/menopausal journey will be smoother and healthier.

Post-Menopausal Women (~Age 55+)

She can fast whenever she wants, just like a man. There is one exception, where she needs to throw a progesterone building day at least once a week. So if she's fasting a lot during the week, let's say six days out of the week, she's doing low carb, she's rocking out with her workouts, and keeping that insulin really sensitive, one day a week, she needs to not fast. She needs to eat healthy foods, do yoga. Wwe don't want to completely lose sight of progesterone.


Georgie Kovacs: For those in perimenopause, if they are late stage, the cycles are unpredictable, so how does one map her cycle and incorporate fasting at the right time?


Dr Mindy Pelz: If you don't know when your cycles are coming, you need to clue in on a few things. One, if you're spotting, and then two weeks later, you have your period, in that time period, that is progesterone knocking on your door. So lean into some foods like your butternut squash with chicken broth, squashes, potatoes, beans, if that works for you, tropical fruits, citrus fruits. These are foods that build progesterone. When you start spotting and you're waiting, waiting, waiting don't fast.


The other thing to clue in for women in those years is the anxiety, which really kicks in as progesterone goes down. And so when progesterone goes down, or when you're feeling anxious, again, same thing, you want to make sure that you're not throwing longer than 13 or 15 hour fast in those anxious periods because that's progesterone, knocking at your door. Otherwise, you can do really well intermittent fasting, if that's all you want to do.


If you want to do a three-day water fast or a 24 hour fast, which helps with the gut repair or an autophagy fast, which is 17 hours and helps you detox - all of that needs to be done at the first half of your cycle. The minute you start to bleed, you have to be really sensitive.


Georgie Kovacs: Tell us about your book, The Menopause Reset.

Dr Mindy Pelz: My book is actually a gift to my audience, because they asked me to write it. I wasn't planning on writing another book, but once I shared my success story with perimenopause, I received a lot of comments from the community asking me to share it in a book. I give women the steps on how to start fasting. Next year, a similar book, but it is targeted to those under 40, will be released.

Georgie Kovacs: What else do you want women to know about fasting?

Dr Mindy Pelz: You can be the busiest CEO, and you can fast. You can be the poorest person, and you can fast. You don't need time, you don't need money.

Georgie Kovacs: What is your greatest hope for women's health?

Dr Mindy Pelz: That is very clear. I want women to believe in their health. We were born with superpowers Look right now, at this healthcare crisis that we are in. It is going to be women that are going to lead us out of this. And we're going to lead it out by saying, “Enough. Don't give me another prescription unless I'm going to die. No more prescriptions. No more needless surgeries. I'm going to start by learning nutrition. I'm going to learn how to take care of my microbiome, I'm going to learn about lifestyle. I'm going to stop rushing and I take insane care of my health so I can step into my power.” And I want women to feel that. We were designed to not only thrive, have amazing energy, be the weight we want to be, shine, and then turn around and bring our brilliance to the rest of the world. And that is what I want women to understand.


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