Intermittent fasting seems to be having a face-off right now with the ketogenic diet for supremacy at the “Fitness Industry Over-Reaction Awards”.

The answer to whether women should do intermittent fasting is like pretty much every other question about the best method…

“It depends”.

Whether it’s fair or not, women are a different animal to men and certain things need a bit more care and thought.

As such, some things that might seem cool and en vogue, might just make things a whole lot worse in your efforts to finally get a body you can live with in the long-term.

Here are some things you should know about women and why many struggle with intermittent fasting despite hearing that it’s the best thing since not eating sliced bread.


In a nutshell, this is what goes down…

Your hypothalamus produces Gonadotropin Releasing Hormone (GnRH).

GnRH tells the pituitary gland to release Leutenizing Hormone and Follicular Stimulating Hormone.

These lead to the production of progesterone and oestrogen, the key players in the female cycle.

If all is well, ovulation occurs.

What has that got to do with Intermittent Fasting (IF)?

Any kind of diet that elicits a starvation/famine response (whether real or perceived), increases the stress hormone cortisol which is known to interrupt production of GnRH and by extension, ovulation.

Female mammals are known to produce greater amounts of kisspeptin, a molecule which stimulates GrNH production. 

This molecule is more sensitive to changes in hormones that regular hunger and satiety levels such as leptin and ghrelin.

The hormones progesterone and oestrogen are also sensitive to calorie intake which is likely to be a survival mechanism.

It makes sense to not ‘allow’ a female to get pregnant when calories are in short supply because one or both of the mother and child would likely experience difficulties fairly quickly.

What we can take from all of the above is that women are much more prone to physical and mental distress as a result of nutritional stress.

Creating any kind of negative energy balance in the medium-to-long term will more than likely lead to a hormonal cascade that brings all sorts of problems.

This could be caused by…

  • Eating a low calorie diet for too long
  • Eating poor quality food
  • Doing too much exercise
  • Enduring a lot of stress for various reasons in life
  • Chronic inflammation from regular intense exercise
  • Not getting enough rest


All of the above tend to feature in drastic fat loss attempts.

You go from 0-100mph on your exercise regime, drop your calories as low as possible (maybe even replacing meals with powders and drinks of poor nutritional quality), stress about your diet and how good you look in the gym, how fast or slow results are coming AND because you have a normal life, you don’t get enough sleep to deal with it all!

To make things worse, stress also converts progesterone to cortisol leading to further progesterone:oestrogen imbalances and affecting your period and feelings of well-being.

If you feel crappy, you’re unlikely to stick to whatever plan you’re on for long, no matter how much you want to lose a few pounds!

It would then also seem logical to assume that, if you’re trying to implement one of the more extreme IF methods (such as just having one meal per day), you will probably experience big deviations from the normal balance of these hormones and experience a bigger starvation response.

It follows that in most females, CERTAIN TYPES of intermittent fasting may cause greater psychological stress whilst also affecting your reproductive system.

You may not care at this point if you just want to lose fat, but the reality is that there is so much interlink and crossover between your digestive system and your reproductive system that big changes in one will lead to big changes in the other.

Ultimately, a smooth path to losing body fat is highly unlikely.


This is purely anecdotal but I have used a version of intermittent fasting with great effect in ladies who have reached a post-menopausal stage with no adverse effects reported.

They lost a ton of body fat, experienced better health (on medicinal testing) and better subjective experiences of general well-being.

Draw your own conclusions about hormonal changes at that time of life.

It would appear FROM MY EXPERIENCE that intermittent fasting may have less effect on the balance of things at that time of life and therefore be more successful as a fat loss tool in the long run.


Not so fast.

As usual, it’s not a black and white, yes or no question.

The key things to consider are:

  • What is your diet history?
  • Does your body panic and stress out now at the first sight of calorie restriction?
  • Are you used to the stress of your exercise plan or is that all new as well?
  • Have you already slowly and carefully reduced your calorie intake before reaching this decision point about using intermittent fasting?
  • What are your stress levels like in average daily life?
  • Do you sleep well?
  • What is the quality of your food intake right now?

If you are in great shape, you eat clean most of the time, you lead a life with stress firmly under control and you sleep well, then intermittent fasting may produce a new stimulus and fit well.

Even then, I would suggest proceeding with caution and using a gentler form of IF such as…

  1. Fast from dinner to dinner once or twice in each 7-10 day period.

    This will bring about a reduction in your calorie intake overall but without ever leaving your body in fasted state for too long or too regularly.

    On other days, your food intake should be of maintenance calorie level and consist of good quality food/nutrients.

  2. Drop your breakfast only.

    Some people do well on this as they only have until lunch before they can eat and daily calorie reductions are smaller and therefore less likely to cause any of the shock reactions detailed above.

Try either of those methods and see how you feel and whether there is any reaction or affect on your period.

Even if you are more about losing fat than getting pregnant at this point, remember all of your systems are closely interlinked.

We also know that changes in estrogen function leads to changes in metabolic functions from digestion and recovery to mood and bone turnover.

 Another key step that can really help is to supplement with Branch Chain Amino Acids.

Amino acids help activate estrogen receptors, halting appetite and regulating peptides that reduce food cravings.

It follows that maintaining amino acid intake whilst fasting from solid food, may go a long way to keeping things much more in balance.

Take an amino acid drink during your fasts to help keep hormones at more normal levels.


I don’t recommend intermittent fasting if you…

…are pregnant

…have a history of eating disorders / starvation-binge cycles

…suffer from a lot of stress on a regular basis

…have poor sleep patterns on a regular basis

I also suggest that if you are new to ‘fat loss’, working out and getting healthy, there are many things you should start with which will deliver great results without the potential drawbacks intermittent fasting can bring to women such as:

  • Focusing on cleaning up your diet and removing processed food
  • Eating more vegetables and clean protein
  • Reducing you carbohydrate intake (you don’t need to eradicate them!)
  • Upping your water intake
  • Moving 3-4 times per week with purpose

Start there and focus on those things until they are lifestyle habits, then you may like to consider the benefits intermittent fasting can bring if managed and observed carefully in each individual!

You’re unique – find out what works for you, not the Instagram models!