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Fasting for women- how to do it according to your monthly cycle

Updated: Mar 15

Intermittent fasting and fasting are topics that are talked a lot in the health space. Both definitely have their benefits for health, but it's important to understand whether they are right for you.

I covered this year intermittent fasting in my blog- what is it, the benefits and how to go about it. But in this blog I would like to focus more on women and cover the following:

  • How should women start doing intermittent fasting

  • What are benefits of intermittent fasting and fasting

  • How should women move into longer fasts

  • How should you prepare for a fast

  • How to intermittent fast and fast around your monthly cycle

  • The importance of liquids during fasting

  • Who should NOT fast

Intermittent fasting and fasting for women- how to go about it

Intermittent fasting for women

Women bodies are more sensitive due to hormonal changes throughout the month. We should not go about intermittent fasting and fasting blindfolded and hard-knuckle through them, same as we should not go hardcore keto for long periods of time. Our bodies need different types of nutrition depending where we are in our cycle.

If you have never done any intermittent fasting or fasting, it's better to start with intermittent fasting first. Intermittent fasting is about eating your meals during specific time window of the day and then not eating the rest of the time.

It's good to start practicing intermittent fasting by eating your meals during 12h window during the day and then fasting the rest of the time. So let's say you eat your 2 or 3 meals between 7am and 7pm and then stop eating at 7pm and eat only the next stay at 7am. You can choose your own time-frame (from 6am to 6pm, from 7am to 7pm, from 8am to 8pm), but 12h is a good starting point to take a break from food. Drinking water and herbal tea without sugar or honey is ok during the fasting time- they don't take you out of fast. Ideally you should not push your last meal after 7pm. It's good to give your digestion a rest 3+ hours before bed time, as your digestion system is slowing down after 6pm.

What are the health benefits of fasting?

  • It's a great tool to loose weight and to heal your body- brain health, gut health, hormones

  • Promotes the secretion of human growth hormone, which is known to help to increase muscle strength, improving workouts

  • Human growth hormone is also slowing down the ageing process

  • Normalises insulin sensitivity (insulin is a fat storage hormone)

  • Lowers LDL cholesterol

  • Normalises your hunger hormone ghrelin

  • etc

We have two ways we burn energy in our bodies- when we eat our foods and when we are in our fasted state and then use the food and glucose we have stored for energy. When you go on a keto diet and consume very few carbohydrates- you are making yourself a good sugar burner. But fasting is a really good way to turn yourself into fat burner. Fat burner is where your body decides that there is no food coming in- your glucose is going down- so your body goes for glucose in your fat and starts to burn that.

If your body is able to burn both the sugar and the fat, then this is where you loose weight. If someone is loosing weight, they are already starting to see the benefits to health- improved energy, better brain health, better glucose and insulin markers, better hormonal health. We want to be metabolically switching- from a sugar burner to a fat burner and vice versa.

People on keto diet, if they are not fasting, they are working in a low-carb state. There is a good chance these people are not metabolically switching. You are not accessing that fat burner system, if you only go low-carb diet.

If we compress our eating window and elongate our fasting window, we are going to be able to make a deeper change in our metabolic state.

How to go about fasting?

When we start packing on more weight, we go and start demonise our bodies- creating negative energy around ourselves. Look at yourself, appreciate where your body is at the moment and decide how can you start to practice intermittent fasting for your body. It's important to be intuitive about it- listen to your body. Also if you have health concerns, it's good to work with a health-practitioner before starting to do longer fasts.

Intermittent fasting

If you go 13 to 15 hours without food during the night, your body will make a switch to fat burner, which means glucose will go down, body will switch over to fat burning mode and start to make ketones, by burning your fat. Your energy levels will improve, inflammation markers come down, you start to make more human growth hormone.

17-hour fast

This is where autophagy starts to kick in. Autophagy is your body's way of cleaning out damaged, old cells so that it can generate new healthier cells. Your glucose in the cells, liver and muscles begin to decrease rapidly, which causes your body to burn stored fat to keep up with the needed energy.

24-hour fast

Your body enters into a state called ketosis, where you are burning your stored fat cells for energy. As the fat cells are broken down for energy, ketone bodies are created and released into your bloodstream. Also ketone bodies become a fuel for your brain, when glucose is scarce, which can lead to a better mental performance, mental clarity. Your brain also starts to increase the production of brain-derived nootropic factor, which supports the growth of brain neurones, improving the long-term memory, learning, coordination.

Your body's gut microbiome gets fully reset. You get stem cells that help with fighting SIBO and candida. This is where you start repairing your gut.

36-hour to 72-hour fasts

You are deep in fat burning state. Your dopamine pathways start to kick in, more dopamine receptor sites gets produced. You improve your anti-aging markers and also at 72h fasts your immune system reboots itself.

Preparing for fasting

Before you plan to do fasting, it's important to prepare your body for it.

  • Cook with good healthy oils and not with the bad oils (such canola oil, cottonseed oil, sunflower oil- they are making you insulin resistant). Switch your seed oils around and use olive oil, tallow, ghee, coconut oil

  • Switch from processed carbohydrates (gluten and gluten free) to nature's carbohydrates (fruits and vegetables)

  • Get out from your food the toxic ingredients, like artificial flavourings, red dyes.

  • You can try and push your breakfast back an hour. You want to stretch the breakfast time and give our body the hermetic stress, which is a good stress- makes the body a bit uncomfortable so it can build itself stronger. Push it back every day a bit more than an hour. If you are really agitated, just stay there for couple of days. Give your body a chance to heal. Your hunger hormone ghrelin will switch off.

Your first step should be to get to 13-15 hour intermittent fasting. Try doing it regularly for couple of weeks, up to one month. Try the below:

  • For 5 days do 13-15-hour fasting during the night

  • 1 day- you push the fast a bit further (maybe have one meal a day) to stimulate the autophagy

  • 1 day a week you won't do longer fast and have 3 nourishing meals with 12h break from food at night

Fasting variation is very good for the body and very important for women. You need to be comfortable to be able to do 24-hour fast if you take on the 36-hour or 48-hour fast (once a quarter). 72-hour fast is only really needed once a year- which helps cleaning out any cancer cells that are forming.

Women and fasting

We have a hierarchy system for our hormones. At the bottom of the hierarchy are your sex hormones (oestrogen, testosterone and progesterone). What will greatly influence these hormones is the hormone above it- insulin. Women with PCOS (Polycystic Ovary Syndrome) are often insulin resistant. If your insulin is out of balance or you are insulin resistant, you are throwing the sex hormones off- you are not getting enough progesterone, which is a big issue for your emotional health. Above insulin is cortisol. If cortisol is high in your body, then it's more difficult for the body to manage insulin and also to produce progesterone. At the top of the hierarchy is a feel-good-hormone oxytocin, that we get from hugs, petting our pets, from great conversations with friends and loved ones. If you manage to keep these hormones in balance in this order, then your body should be humming.

We need to look at the needs of the sex hormones. If you are a menstruating woman- then your oestrogen wants you to be insulin sensitive, so you need to keep insulin down.

A normal cycle of a woman is anywhere from 21-35 days and consists of 4 phases:

  • Menstrual phase (your monthly period, from day 1 to 5): Your body is shedding the lining of your uterus called the endometrium, which leads to bleeding (oestrogen and progesterone are very low)

  • Follicular phase (from day 1 to 13): Right after your period and where both oestrogen and progesterone begin to rise

  • Ovulatory phase (day 14): Oestrogen hormone peaks and at the end of this (short) phase, one of your ovaries releases an egg, and progesterone and testosterone hormones rise

  • Luteal phase (from day 15 to 28): A mature egg is released and if not fertilised by sperm, hormone levels decrease and the cycle starts again. Progesterone is elevated as well as increased levels on oestrogen.

Women- food, fasting and exercise

How to intermittent fast and fast during your cycle?

In 1-10 day of your cycle- you do great both with fasting and you do great with ketogenic diet. With fasting and ketogenic diet you improve oestrogen sensitivity as well as insulin sensitivity.

In day 11-15 where you normally have your ovulation, you have oestrogen at its highest, you have testosterone at its highest, and a little bit of progesterone. Do intermittent fasting (13-15h fast is good)- lean in more on foods, diversity off vegetables, leafy greens, good quality proteins, and healthy fats, no alcohol. Liver is your organ that needs to break the hormones down, so keep it working well especially during this phase.

After ovulation you can do couple of days longer fasts and do keto a little more.

In day 19 your body wants to make progesterone (a week before your period). Do not fast as then your cortisol (stress hormone) level goes up and therefore your progesterone goes down. Try 11 to 12 hours intermittent fasting. Lean in more on foods that raise glucose and supports progesterone (squashes, potatoes, citrus fruits, tropical fruits, beans, seeds like sesame seeds and sunflower seeds, grass-fed beef etc.)

Women in menopause

Women over 40 when they start entering into peri-menopause, their oestrogen declines and they will become more insulin resistant. For women in menopause it's important to start off with intermittent fasting- and slowly ease into longer fasting. It's also good to do one or two days a week, where you don't do longer fasts (again 11-12h intermittent fasting).

Make sure you consume enough liquids while fasting

It's very important to note, that while you are fasting, you should consume enough liquids- 2-3 litres a day. Remember, we are 60% water as humans. So consume liquids like water, tea (not sweetened), bone broth, coffee (black and be mindful on the quantity). Avoid any sugary drinks. It's also good to add electrolytes to your water to increase the potassium, magnesium and phosphorus levels in your body.

Who should not do extended fasts?

  • Children

  • Underweight people

  • Anyone with eating disorders (anorexia, bulimia etc)

  • Also people with type 2 diabetes (should only do fasting under supervision of their healthcare provider)

Hunger is normal when fasting. But if you are feeling weak, shaky, dizzy during fasting, then it's time to break the fast and eat a nourished meal. Most important is to listen to your body.

If you have health challenges, want to improve the way you eat to support your hormones, don't hesitate to reach out to me for health and nutrition coaching at


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