Intermittent Fasting for PCOS

Updated on 23 October 2020

I’m a firm believer in a good PCOS Diet and eating right. But, it turns out that WHEN you eat is just as important as what you eat when it comes to PCOS. Intermittent fasting has become something of a trend in recent years and many people use it as a tool to lose weight, control sugar levels and have seen many other health benefits. So, is intermittent fasting for PCOS something we should consider adding to our way of life?

Let’s have a look at some of the science behind it.

What is Intermittent Fasting?

Intermittent fasting is when you alternate between a fed and a fasted state (1). To really understand what we mean by fed and fasted states we need to dig a little deeper and actually figure out what is happening in our bodies.

Okay, so we know that when we eat foods with protein and carbohydrates, insulin is released. Insulin controls the movement of glucose from our blood streams to our cells and also manages the storage of excess energy (turns it into fat).

Now, after a meal, insulin levels stay relatively high and slowly start to drop over about a 12 hour period. Once insulin levels have dropped and the body needs to rely on its stored energy supplies, you enter into the fasted state (2).

Basically, every time you sleep, you are entering into a fasted state.


What are the Benefits of Intermittent Fasting?

There are a number of health benefits of fasting. Here are just some of them (3):

  • Improved mental clarity and concentration
  • Weight and body fat loss
  • Lowered blood insulin and sugar levels
  • Reversal of type 2 diabetes
  • Increased energy
  • Improved fat burning
  • Increased growth hormone
  • Lowered blood cholesterol
  • Prevention of Alzheimer’s disease (potential)
  • Longer life (potential)
  • Activation of cellular cleansing (potential) by stimulating autophagy (a discovery that was awarded the 2016 Nobel Prize in medicine)
  • Reduction of inflammation

That list of benefits looks pretty impressive. But how on earth might it help women with polycystic ovary syndrome?

Intermittent Fasting and PCOS

There are a couple of ways that I think we could use fasting to see improvements in our PCOS symptoms. Looking at the list above, let’s have a look at how some of these things might apply to us.

Weight loss

For so many of us living with PCOS, we know all too well that it is so tricky to lose weight with PCOS and we seem to put it on so easily. It is so frustrating! And we have been told over and over again that we need to lose weight and “we’ll be fine” but nobody actually tells us HOW to lose weight with PCOS.

Our body’s tendency to over produce insulin and the link between PCOS and insulin suggests that high insulin levels are at the heart of our seeming inability to lose weight. We tend to be insulin resistant – something that intermittent fasting can improve as insulin levels begin to lower.

Studies have also shown that intermittent fasting can be an effective weight loss strategy (4).

And remember, the focus here is managing insulin levels, not necessarily caloric restriction.

Lowered Insulin Levels

We’ve already spoken about how lower insulin levels can help with weight loss but we haven’t spoken about how lowered insulin levels may help with our PCOS.

Well, we know that insulin is closely linked with PCOS and we know that our ovaries tend to be over sensitive to insulin. All women produce some testosterone from their ovaries. Women with PCOS, however, produce too much testosterone.

And it is insulin that stimulates the release of testosterone from the ovaries (5).

So, by lowering insulin levels, we will be able to lower testosterone levels and be able to better manage a lot of the symptoms of PCOS.

Lowered Blood Cholesterol

Women with PCOS also tend to have higher cholesterol and this puts us at greater risk of cardiovascular disease (6). If intermittent fasting can help improve cholesterol levels, this will also give us long term health benefits.

Reduction of Inflammation

Inflammation can make us feel uncomfortable and generally achey. And if we were to have a blood test right now, we would probably see that our inflammatory markers are raised. Women with PCOS struggle with chronic low grade inflammation.

This inflammation can also decrease our body’s sensitivity to insulin. So, we need more insulin than normal to deal with blood sugar and this makes our general PCOS symptoms much worse.

So, anything we can do that will help to manage inflammation would be helpful for our PCOS.

Those are just a few of the reasons that I think that intermittent fasting might be helpful for women with PCOS.

Who Shouldn’t try Intermittent Fasting?

I’m going to be honest here. I don’t necessarily think that intermittent fasting is for everyone and there are some women who should be careful of fasting and consult their doctor before they start fasting.

  • Pregnant women – Fasting when pregnant is not a good idea and should be avoided.
  • Women taking prescription medication – If you are taking any prescription medication, you should consult your doctor before trying any form of fasting. Insulin sensitising drugs, like Metformin, can cause you to have bouts of low sugar levels when fasting.
  • Anyone with a history of an eating disorder
  • Women who are already underweight

Time Restricted Eating

Now you might be wondering how to get started with intermittent fasting. One way is to make the most of your current daily eating habits.

You are practising intermittent fasting every single time you sleep. You are not eating and your insulin levels drop, and you start to move into a fasted state.

So, to get started on intermittent fasting, you need to become more intentional about WHEN you eat and aim to shorten the period of time in which you eat. For example, if you have breakfast every morning at 8 am, make sure that you stop eating by 8pm. That will give you 12 hours of intermittent fasting per day.

Working with your body’s circadian rhythm

What is super interesting to me is that our bodies have a daily hormonal rhythm, the circadian rhythm. And that also influences our bodies’ sensitivity to insulin.

We tend to be less sensitive to insulin in the evenings, when we are eating our biggest meals. Basically we could eat the EXACT same meal for breakfast and dinner and we would need less insulin at breakfast time. Why? Because our bodies are more sensitive to insulin in the morning.

So, with this in mind, what if we ate dinner by 6 or 7 o’clock? That way, we are eating when our bodies are still somewhat sensitive to insulin and we can start to extend the length of time that we are fasting for.

Seems to make sense to me!

Now, I would love to hear from you! Do you have any experience with intermittent fasting? Have you seen any benefits or do you feel that it may even have made your symptoms worse?

Leave me a comment below and let me know!

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Tarryn Poulton

Tarryn Poulton

Tarryn Poulton is a PN1 Certified Nutrition Coach and PCOS expert who has been a leader in the online PCOS space for over 8 years. Tarryn has the support of leading clinicians from around the world who support her scientific approach to understanding and talking about PCOS this includes all medical journals and ongoing research. You can read more about Tarryn and the team here.

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