Intermittent fasting for weight loss? Women planning to start a family may want to reconsider

Tesla and SpaceX CEO Elon Musk recently shared that 'intermittent fasting' was the secret to his fitness at the age of 51.

Last month, the world's richest man revealed he lost 9 kgs with intermittent fasting and now 'feels much healthier'. He said that he finds the 'zero fasting app quite good' that helps track his food intake.

Musk isn't the only one who has shared the benefits of fasting. Twitter CEO Jack Dorsey also follows Vipassana meditation and intermittent fasting. He had previously charted out his food chart for dinner, which includes fish, chicken or steak, and 'a lot of greens'.


In 2019, intermittent fasting was one of the most popular diets, according to a HealthifyMe survey.

While it has worked as a proven method to lose weight and stay healthy for tech bosses, intermittent fasting may have its limitations - especially in adult women.

According to a recent study, intermittent fasting may affect female hormones in obese women.

A team of researchers from the University of Illinois at Chicago monitored a group of pre- and post-menopausal obese women, who were using the 'warrior diet' technique of intermittent fasting, for eight weeks. They were following the routine under the direction of Krista Varady, professor of nutrition at UIC, who is also the lead author of the study.

When a person follows the warrior diet, s/he is allowed to eat in the four-hour window each day. During these four hours, dieters eat without counting calories before beginning a water fast until the following day.

For the study, the researchers measured the differences in hormone levels between groups of dieters who adhered to four- and six-hour feeding windows and a control group who followed no dietary restrictions, using data from blood samples. Women in their 40s, who are perimenopausal, were not included in the study.

The findings showed that the levels of sex-binding globulin hormone, a protein that transports reproductive hormones throughout the body, remained unchanged after eight weeks of dieting. Both testosterone and androstenedione, a steroid hormone that the body uses to make both testosterone and oestrogen, exhibited the same behaviour.

Dehydroepiandrosterone (DHEA) - a hormone that helps enhance ovarian function and egg quality - was significantly lower in both pre- and post-menopausal women, declining by about 14 per cent, after the trial.

While the DHEA drop was the most significant in both pre- and post-menopausal women, the levels remained within the normal range by the end of the eight-week trial.

Varady said, "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. 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."

In addition, Varady noted that since high DHEA has been connected to the risk for breast cancer in both pre- and post-menopausal women, a moderate drop in levels may be beneficial in lowering that risk.

Estradiol, estrone, and progesterone levels were also measured only in post-menopausal women as the hormones fluctuate in pre-menopausal women due to their menstrual cycles. These hormones are all essential for pregnancy. At the end of eight weeks, these hormones had not changed in post-menopausal women.

In comparison to the control group, which lost almost no weight, women in the four-hour and six-hour dieting groups lost between 3 per cent and 4 per cent of their starting weight throughout the study. Additionally, the dieters noticed a decrease in oxidative stress biomarkers and insulin resistance.