I have been asked a lot lately about IF. When ever I have a question like this I always go to Precision Nutrition.
Helen Kollias wrote this article last year so I thought I would share with with all of you.
Some women who try intermittent fasting experience missed periods, metabolic disturbances, and even early-onset menopause. Sure, it can work for some women. But here’s why intermittent fasting could be bad— even counterproductive — for your goals
Intermittent fasting and your health
Intermittent fasting (IF) is the practice of going for prolonged periods without eating.
There are lots of ways to do it, including meal skipping, alternate-day fasting, Eat Stop Eat, and others (PN’s free e-book on intermittent fasting offers an excellent rundown).
There’s evidence that IF, when done properly, might help regulate blood glucose, control blood lipids, reduce the risk of coronary disease, manage body weight, help us gain (or maintain) lean mass, reduce the risk of cancer, and more.
We even published an article suggesting it could help us live longer and stronger. So, naturally, a lot of people are trying it.
An accompanying trend that’s emerged: While some women who try IF say it’s the best thing that’s happened to them since grapefruit, others report serious problems, including binge eating, metabolic disruption, lost menstrual periods, and early-onset menopause. This has happened in women as young as their mid-20s.
Maybe my mom was on to something. Maybe IF is totally different for women than for men.
Fasting and female hormones
In the grand scheme of your life’s health decisions, experimenting with IF seems tiny, right? Unfortunately — for some women, at least — it seems like small decisions can have big impacts.
It turns out that the hormones regulating key functions like ovulation are incredibly sensitive to your energy intake.
In both men and women, hypothalamic-pituitary-gonadal (HPG) axis — the cooperative functioning of three endocrine glands — acts a bit like an air traffic controller.
- First, the hypothalamus releases gonadotropin releasing hormone (GnRH).
- This tells the pituitary to release luteinizing hormone (LH) and follicular stimulating hormone (FSH).
- LH and FSH then act on the gonads (a.k.a. testes or ovaries).
- In women, this triggers the production of estrogen and progesterone — which we need to release a mature egg (ovulation) and to support a pregnancy.
- In men, this triggers the production of testosterone and sperm production.
Because this chain of reactions happens on a very specific, regular cycle in women, GnRH pulses must be very precisely timed, or everything can get out of whack.
GnRH pulses seem to be very sensitive to environmental factors, and can be thrown off by fasting.
Even short-term fasting (say, three days) alters hormonal pulses in some women.
There’s even some evidence that missing a single regular meal (while of course not constituting an emergency by itself) can start to put us on alert, perking up our antennae so our bodies are ready to quickly respond to the change in energy intake if it continues.
Maybe this is why certain women do just fine with IF while others run into problems.
Why does IF affect women’s hormones more than men’s?
We’re not totally sure.
But it might have something to do with kisspeptin, a protein-like molecule that neurons use to communicate with each other (and get important stuff done).
Kisspeptin stimulates GnRH production in both sexes, and we know that it’s very sensitive to leptin, insulin, and ghrelin — hormones that regulate and react to hunger and satiety.
Interestingly, females mammals have more kisspeptin than males. More kisspeptin neurons may mean greater sensitivity to changes in energy balance.
This may be one reason why fasting more readily causes women’s kisspeptin production to dip, tossing their GnRH off kilter.
Now, If you too the time to read all of that read this.....THERE IS NO FAST WAY TO LOSE WEIGHT
It is as simple as eating clean, Exercising and having a balanced life. Follow the 80/20 rule. You will feel 100 times better eating clean than eating junk all the time.