• Energy
  • Hormones
  • Nutrition

The Woman’s Guide to Intermittent Fasting

By now, you probably know someone who does intermittent fasting, or maybe you have tried it yourself And why not? The countless articles and influencers praising this diet trend may have you believing it can help with everything from weight loss to brain power

For many people, intermittent fasting can be beneficial but for women considering giving this trend a go, you need to proceed with caution! 

If you’re not in tune with your body, fasting for prolonged periods of time may be largely ineffective, or worse, they can actually do more harm than good


First, let’s get our facts straight…

What is Intermittent Fasting?

Intermittent fasting is simply going for short or medium periods of time without food Simple, right? That’s why it’s been so popular No fancy diets to follow or complicated recipes to make Just stop eating!

The “not eating” window can vary in length Some are as short as 12 hours and include sleep time Some are as long as 16, 20 or 24 hours

There are also different ways to fast Some people do it everyday Others do longer fasts a few times per week

This trend is hot right now, not just because it’s easy to do, but because the possible benefits are extensive and very appealing Weight loss is an obvious benefit, but studies also show that fasting can help lower cholesterol, reduce sugar cravings, improve blood pressure, improve sleep and concentration Some people even report increased endurance and athletic performance

What Makes Intermittent Fasting Trickier for Women?

Ladies, listen up That list of benefits above may sound appealing but if you don’t understand what you’re doing, fasting can actually do the opposite of what you want!

Whether motherhuud is on the horizon or not, a woman’s body is naturally built for reproduction When you don’t eat for extended periods of time, your body thinks it's starving and it goes into “protect and preserve” mode This mode is about survival! Your body will actually hang on to weight (in the event you needed to say, survive a famine) and it increases your hunger hormones signalling to your brain to go get some food ASAP!

It also slows down things like your fertility, so you don’t waste energy on non-essential things like growing a baby

If you’re not interested in having a baby, this might not sound like a big deal, but when you mess with reproduction, you mess with hormones And, when your hormones are out of balance, you set yourself up for a whole range of health problems which are very likely the polar opposite of what you are trying to achieve with fasting

Women Beware: Possible Side of Effects of Intermittent Fasting

Fasting for long periods can affect the hypothalamus or the part of the brain that regulates hormones like estrogen which plays a critical role in your monthly cycle When this happens, you could notice:

  • Low energy

  • Sugar cravings

  • Weight gain

  • Trouble concentrating

  • Dull hair and skin

  • Fertility challenges

Fasting can also disrupt cortisol production When this happens, you might notice:

  • Increased anxiety

  • Low energy and brain fog

  • Inability to sleep


What About Fasting and Exercise?

If you’re adding a regular exercise routine on top of intermittent fasting, it’s good to know the potential risks Fasting tells your body it is deficient in nutrients and often, when you add on the stress of exercise, it can cause your cortisol levels to skyrocket

If you keep increasing your stress through exercise without fuelling your body properly, you will constantly be in survival mode and this can mess with your menstrual cycle You may even start storing more belly fat!

Instead of the weight loss and super powered brain you were hoping for, intermittent fasting may actually cause disrupted periods, higher anxiety, worse athletic performance and often, weight gain – the absolute opposite of what you’re looking for!

As you can see, intermittent fasting can have many benefits, but the potential negative side effects may be enough to scare you away!

How to Fast Safely if You’re a Woman

The big question is: are there still ways to get the benefits of intermittent fasting if you’re a woman?

The answer is YES!

But you need to be smart about it

There’s a few guidelines you can follow to ensure you reduce the risks and just get the guud stuff that fasting has to offer

Here’s how:

  • Don’t fast when you’re on your period Your body is already working hard here so take care of it with nourishing food

  • Tempting though it may be, don’t fast on consecutive days Instead, pick one-two days per week

  • Opt for shorter fasts of approximately 12 hours Going any longer can start a hormonal crash

  • Plan workouts according to your fasting days Do your intense workouts on days that you are not fasting

  • When you are eating, make sure you eat according to your cycle What does that mean? Our blog post on How to Hack Your Cycle with Food will tell you all you need to know

  • Try to time your fasts for the week after your period During this phase, known as the follicular phase, your metabolism slows down meaning you’ll feel less hungry than other weeks Your body actually needs more calories the week before your period so just be aware of these different phases when you plan your fasting days

The key is to listen to your body If the shorter fasts work well for you, consider increasing the length of time But if you start noticing symptoms of hormonal imbalance, stop immediately!

Stop Fasting If….

  • Your period becomes irregular or stops

  • You’re a zombie and can’t sleep

  • You feel off Think: brain fog, grumpiness and general anxiety

  • Your hair and skin looks noticeably worse

  • You’re gaining weight

  • You have or are currently struggling with an eating disorder


The bottom line is that intermittent fasting effects men and women differently so when you read about all the magical benefits, it’s good to keep in mind that there’s no one-size-fits-all approach

Remember: the best diet is the one you can stick to long term Find one that works for you and your lifestyle and stop immediately if you’re trying to conceive, pregnant or notice any of the warning signs

Want more advice on fasting? Get in touch with one of our experts  

We’d love to help