Within my gym its common for a number of the male grapplers to use intermittent fasting as way to lose weight for competition etc and some of the guys I know are big advocates of it. However, like most things as a female grappler it’s not always as straightforward as just doing it the same as the guys! I did try it a couple of times and really didn’t have much success with it and found it pretty difficult so I got researching. Whilst there is research on fasting there isn’t that much available on gender differences (unless you’re a rodent) so this blog will try to pull some of this together with my own experiences so you can be aware of some of the things to watch for.

I’m so hungry!!!
We can feel way more hungry when fasting (and it’s not a good thing!) – If not done correctly women can get a hormone imbalance in particular our body produces more or the hunger hormones leptin and ghrelin (1). Simply put it creates an insatiable hunger as our body thinks it need to eat to protect ourselves an any potential baby (even if you’re not pregnant). These will continue to get louder and increase the chance of fully breaking your diet and having a full on binge!

Trouble Sleeping
A woman’s body is much more sensitive to signs of starvation. It is possible that fasting may trigger your body into thinking that it has a problem (particularly if in calorie deficit and under eating). It will want you to stay awake so that you can find food and eat which can cause sleep problems. I can’t say it’s definitely caused me to lose sleep but I also really love my sleep so I have to question if it’s worth the risk!

Insulin sensitivity and glucose tolerance
This was a particular interest to me as I have PCSO which includes as a symptom insulin resistance which can affect my weight loss. Now a variety of sites state that one of the benefits of intermittent fasting is improve insulin resistance. But the research often quoted (2) to support that really shows gender difference in fact –

1. women in studies covered by the review did not experience increased insulin sensitivity with intermittent fasting regimes
2.  intermittent fasting women actually experienced a decrease in glucose tolerance.

So whilst male metabolisms showed improvement females who were fasting actually had a decline in their metabolism. Which isn’t great for weight loss or general health.

Fertility
It’s generally understood that fertility and nutrition is linked but in terms of fasting the majority of the research is linked to rodents. It is mixed in terms of findings, on one hand  reduced calorie intake can length fertility periods for female rats (3). Yet on the other hand reduced calories can trigger a stress response and limit a female rats reproductive cycle (4).

On reflection of my own experiences I only fasted on non-training days which I actually really limited when I could do it (only 1-2 times per week). Overall I think the main effect that intermittent fasting had for me was simply reducing my calorie intake which in reality can be done in other ways. Without doing blood tests I can’t say if I experienced any side effects from fasting other than being really hungry and watching the clock until I could eat. I’ll be honest, Mint tea used to take the edge off but on some days I was ready to eat my colleagues.

As I said at the start of my article information is limited on gender difference but personally I think there are other ways for female grapplers to make-weight. Ultimately women have body fat for different reasons to our male grapplers so we may just also have to accept we need to try different approaches to lose it too!

References

1. Intermittent fasting dietary restriction regimen negatively influences reproduction in young rats
2. Alternate-day fasting and chronic disease prevention: a review of human and animal trials
3. Intermittent Fasting and Fertility
4. Shattering the Myth of Fasting for Women: A Review of Female-Specific Responses to Fasting in the Literature

Photo Credits – Judy van der Velden