Women’s Guide to Intermittent Fasting

A lot of the blogs online around intermittent fasting for women are based on non-human studies, they misrepresent data and don’t even answer the questions that women really have about intermittent fasting. We intend to.


  • Intermittent fasting promotes fertility in women
  • Intermittent fasting can fix common female hormone imbalances

This blog will shed some light on intermittent fasting for women and put you at ease by showing you what is true and what is false. The hope is that this blog makes you more confident in deciding how to approach your health.

I will address the two most common questioned we get concerning women and intermittent fasting.

  • Hormonal imbalances
  • Fertility issues

Understandably, these are both warranted concerns and important to consider before jumping into a certain way of eating. Weighing the benefits against the downsides is a critical step before starting anything new.

What happens though, when no one can give you a definitive answer. We get uncertainty.

So before we jump, in let’s weigh up the benefits against the drawback of intermittent fasting for women.

Here are just a few benefits:

  • Increases fat loss, while preserving lean tissue (most effective way to lose weight)
  • Increases energy
  • Promotes cellular repair and autophagy (your body’s inbuilt recycling station, it breaks down old, faulty cells and uses that to rebuilt better functioning cells)
  • Reduces insulin and leptin resistance
  • Protects against type 2 diabetes
  • Lowers bad cholesterol, increases good cholesterol
  • Promotes longevity
  • Protects against neurodegenerative diseases such as Alzheimer’s and Parkinson’s
  • Improves memory and boosts brain function
  • Makes cells more resilient, improving immunity
  • Prevents glycation and A.G.Es (responsible for ageing process)
  • Reduces hunger and food cravings
  • Improves our skin, hair and nails

The universal downsides of intermittent fasting

  • There will be a period of discomfort. Only the same anything we try that is new.
  • Keto flu (following our ‘How to Start IF’ guide this can be avoided) *LINK*

The UNTRUE downsides of intermittent fasting for women

  • Hormonal imbalances
  • Fertility issues

Here are some excerpts from popular blogs about intermittent fasting for women.

Blogger 1:

“In animal studies, after two weeks of intermittent fasting, female rats stopped having menstrual cycles and their ovaries shrunk while experiencing more insomnia than their male counterparts (though the male rats did experience lower testosterone production). (6)”

“Unfortunately, there are very few human studies looking at the differences between intermittent fasting for men and women, but the animal studies confirm our suspicion: Intermittent fasting for long periods of time can sometimes throw off a woman’s hormonal balance, cause fertility problems and exacerbate eating disorders like anorexia, bulimia and binge eating disorder.”

The rats in this study were placed under extreme dietary deprivation. They were placed on a fasting protocol similar to that of the 5:2 diet or Eat, Stop, Eat. In the study they were fasted for 24 hours, then ate as they pleased for 24 hours. This cycle was repeated for 12 weeks. This resulted in the rats being placed in a 30-40% calorie deficit immediately. A change this abrupt and a calorie deficit that severe is STARVATION, not intermittent fasting.

Here’s another excerpt from a different blogger.

Blogger 2:

“Now, here’s the tricky part. Although intermittent fasting may have its benefits, women are naturally sensitive to signs of starvation, so intermittent fasting for women is a whole different beast.”

When the female body senses it’s headed towards famine, it will increase the production of the hunger hormones, ghrelin and leptin, which signal to the body that you’re hungry and need to eat (2). Additionally, if there’s not enough food for you to survive, your body is going to shutdown the system that would allow you to create another human. This is the body’s natural way of protecting a potential pregnancy, even if you’re not actually pregnant or trying to conceive.

This is from the study the blogger cited to ‘prove’ their point.

“– before breakfast (after 12-h starvation) and 2 h after food intake. All participants had the same breakfast. The energetic value of the meal was approximately 260 kcal and it contained 4.7 g of proteins, 14.2 g of fats and 28.2 g of carbohydrates.”

260 calories! Are you kidding me – of course your going to be hungry? A 260 calorie breakfast is a slap in the face.

It’s literally the equivalent of 10 brazil nuts or 15 macadamias. Barely a breakfast. But hey, a breakfast that low in calories with high carbohydrate intake like that is bound to spike the hunger hormones and create a ravenous urge to eat more.

Not to mention. While the exact purpose of our hormone leptin is still unclear, higher leptin plays an important role in being able to burn body fat as fuel – a great thing for those losing weight.

Both of these bloggers are actually in favour of intermittent fasting for women and that’s awesome. The sources they cite may be a little questionable because of their lack of applicability and relevance to REAL women, but their heart is in the right place.

Now, I want to switch it from citations of rat studies to time-tested, real world and real women achieving life-changing results from experts in the field.

Blogger 2:

Dr Fung is a Toronto based kidney specialist, having graduated from the University of Toronto and finishing his medical speciality at the University of California, Los Angeles in 2001. He is the author of the bestsellers ‘The Obesity Code’ and ‘The Complete Guide to Fasting’.

I’ve linked to both of these books here:

complete guide
Click to visit Amazon
obesity code 1
Click to visit Amazon

He has pioneered the use of therapeutic fasting for weight loss and type 2 diabetes reversal in his clinic.

Megan Ramos has worked alongside Dr Jason Fung since 2003. She is a clinical researcher by trade, with the majority of her research focusing on preventative medicine. Megan co-founded the Intensive Dietary Management Program with Dr Fung in 2014 after being diagnosed with diabetes herself and was the program’s first guinea pig.

In a podcast named ‘21-day Hero Show’, Megan Ramos was asked how intermittent fasting affect female fertility and hormones.

Here the link to the podcast. Thanks for making this podcast happen!


Her response was amazing!

“With women, we really don’t notice that much of difference to men, despite we’re a lot more hormonally complex. But, there are a few things. That happens with women. Women tend to struggle during certain parts of their cycle the most when it comes to fasting.”

Megan mentions that women tend to find intermittent fasting the easiest just before their menstrual cycle and is usually the hardest during it. The next 7 days are easy, which creates a pattern of intermittent fasting being easy one week then harder the next, then easy again and so on.

Megan then says this process usually takes about 3 months to normalise.

“usually more [so] with women that follow the sort of, standard, first world, developed world processed food diet they tend to be a little bit more hormonally out of whack.”

After this 3 months period:

“Their hormones stabilize. We usually find after about 3 months, women who used to feel really ravenous during their menstrual period don't feel that way more. Because even though their hormones [still] do fluctuate they’re not [fluctuating] as great[ly] once the body has chucked out the garbage foods and are eating food don’t cause a lot big insulin shifts, that, then result in other hormonal shifts. Like with our estrogen and a few others”

Now on the subject of your periods: Megan mentions that for about 3-4 months of intermittent fasting your periods will be out of whack and this is because your hormones have been out of whack prior to fasting!

Megan says Intermittent fasting can actually regulate your hormones back into sync with your body.

“They [women] find after 3-4 months their periods were back to normal even if they weren’t normal before they started intermittent fasting.”

Wait, so… even for women who had irregular periods before starting intermittent fasting, after the normalisation phase, the irregular periods became regular!

So what Megan is saying is it can look something like this for most women:

  • Before intermittent fasting (regular diet): irregular periods (potentially already out of whack hormones)
  • During intermittent fasting (first 3-4 months): really irregular periods (sometimes they stop entirely)
  • Intermittent fasting for more than 3-4 months: Periods become perfectly normal. Even for women who have never had regular periods!

Megan calls this process “the [female] body regulating” during this process your cycle and hormones become normalised.

Here’s Megan again:

“After this process, we actually see an improvement in fertility. I was told I was virtually infertile, and that was in my twenties. And now I’m in my almost mid 30’s, it’s scary! Aha. but now they say I’m as fertile as a teenager. Because you regulate all of your hormones throughout fasting.”

“We actually have over two dozen IDM babies who were accidentally born in the clinic. Most of these women came and sort out treatment for PCOS. Most of them thought they could never have kids. Even though they wanted kids. But they needed to sort out their PCOS, lose weight to sort out their diabetes. Within 6 months hormones that promote fertility that were low came up. And those that stopped fertility came down and normalised. During this time is actually when they fell pregnant.”

“These women were told they would never have babies.”

This is mind-blowing. These women were told they would never have children and within 6 months of intermittent fasting, they were pregnant.

Thanks to Megan Ramos and Dr Jason Fung’s expert experience treating women with intermittent fasting we can now say intermittent fasting actually has a beneficial effect on female hormones imbalances and fertility.

The latest and greatest about everything intermittent fasting. We share the why and how intermittent fasting can help you live a long and healthy life.
The latest and greatest about everything intermittent fasting. We share the why and how intermittent fasting can help you live a long and healthy life.

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