Intermittent fasting and its effects on female hormones

Intermittent fasting (IF) is one of the best methods for losing weight, according to several dietitians. This way of living forces one to eat at a specific window of time and then fast for between 12 and 16 hours each day.

Even though its advantages have long been documented, a recent study found that intermittent fasting may have a negative effect on a woman’s reproductive hormones. While researching obesity, a team at the University of Illinois at Chicago stumbled onto fresh data regarding IF in females.

The researchers evaluated a sample of pre and post menopausal obese women for eight weeks as they followed the ‘warrior diet’ strategy of intermittent fasting, under the direction of Krista Varady, professor of nutrition at UIC.  Their findings have been published in the journal Wiley Online Library.

One can only eat for four hours a day using the warrior diet technique of IF. The participants in this window were free to eat whatever they pleased before returning to their water fast.

By comparing participants who followed IF to those who didn’t, the researchers were able to measure the variations in hormone levels. After eight weeks, Krista Varady and her team noticed that the participants’ levels of sex-binding globulin hormone, a protein that transports reproductive hormones throughout the body, were stable. This held true for other hormones like testosterone and oestrogen as well.

However, both pre and post menopausal women’s levels of DHEA, a hormone that fertility clinics use to enhance ovarian function and egg quality, were significantly lower towards the end of the trial. It dropped by about 14%.

‘This suggests that in pre-menopausal women, the minor drop in DHEA levels has to be weighed against the proven fertility benefits of lower body mass,’ Varady said. ‘The drop in DHEA levels in post-menopausal women could be concerning because menopause already causes a dramatic drop in estrogen, and DHEA is a primary component of estrogen. However, a survey of the participants reported no negative side effects associated with low estrogen post-menopause, such as sexual dysfunction or skin changes.’