From sweat-inducing hot flashes to frustrating sleepless nights, the months and years during the perimenopause can bring about big physical changes. According to statistics, roughly 85% of women will experience some kind of symptoms during this transitional phase of life, to varying lengths and severity. 

Recently, you may have seen a growing number of social media posts waxing lyrical about the potential benefits of intermittent fasting, with some people claiming that it can help to reduce menopausal weight gain, as well as minimise the onset of tricky vascular issues like hot flashes. The buzz surrounding this popular eating plan has gained momentum in recent months, racking up a mammoth 5.2 million Instagram posts under the popular hashtag #intermittentfasting.

But like many things related to women’s health, the relationship between menopause and fasting is not straightforward. To help clear up matters, we asked Form’s resident health advisor, Dr. Adam, to tell us more about intermittent fasting, its safety, and its potential benefits for women during midlife.

First up, what exactly is intermittent fasting?

Intermittent fasting is a dieting approach that emphasises when you eat, rather than what you eat. The plan consists of timed ‘eating windows’ – when you can eat your usual diet – and fasting periods, when you’re encouraged to abstain from food entirely, aside from water, coffee, and tea.

The general gist is that by abstaining from grazing outside of these strict time windows, we can expand the amount of time our bodies experience being in a fasted state. Some fairly recent research indicates that the human body may experience a laundry list of health benefits from resting the digestive system, as the process is said to increase cellular repair throughout the body.

The length of each fasting window depends on the specific schedule you follow. For example, the popular ‘16:8’ method involves 16 hours of fasting sandwiched between 8 hours of eating, although some people opt to restrict their eating for longer or shorter durations.

What are the benefits of intermittent fasting during or after menopause?

Although there haven’t been specific studies on fasting during menopause, Dr. Adam says that there is some limited research into how it affects women at earlier and later stages.

“Interestingly, these research studies found that fasting can help women lose weight and improve their metabolism, both before and after menopause,” he notes. “The researchers also found that fasting eating patterns are generally easier for people to stick with than regular diets, leading to a higher likelihood of long-term sustainable results.”

Dr. Adam adds that while the benefits of intermittent fasting are generally discussed in a perimenopausal context, but strategically planning your mealtimes may actually be more helpful after menopause. “This is because of the increased weight gain, insulin resistance, and cardiometabolic risk that is more prevalent during this stage of menopause,” notes Dr. Adam.

But that’s not to say it should be overlooked in perimenopause, as the benefits of fasting seem to have ripple effects elsewhere. “A general reduction of visceral body fat tends to improve vascular function, as well as metabolic markers like glucose and cholesterol, which has been found to reduce menopausal symptoms like hot flashes,” says Dr. Adam. “Whether it’s through time-restricted feeding or alternate-day fasting plans like the 5:2 diet, fasting has been scientifically shown to improve these health markers.”

Are there any drawbacks to intermittent fasting during perimenopause?

It’s difficult to say. Dr. Adam says that it’s challenging to answer this question because there are no published studies that have specifically looked at how fasting affects women during the menopausal transition. “Key hormonal changes during this period, such as shifts in testosterone, estrogen, and progesterone, as well as regulators like sex hormone-binding globulin (SHBG) and dehydroepiandrosterone (DHEA), are all important to consider in a peer-reviewed context,” he notes.

That said, Dr. Adam believes there is little evidence that fasting has a negative effect on these hormones, apart from a slight decrease in DHEA levels before and after menopause. “Lower DHEA levels are linked to symptoms like dry skin, vaginal dryness, and reduced sex drive, but these changes are usually minor,” he assures, “and DHEA levels generally stay within normal ranges without clinical issues.” Interestingly, studies also conclude that hormone replacement therapy (HRT) doesn’t seem to impact weight loss or gain.

Added to this, an accelerated rate of bone loss, which can lead to bigger issues like osteoporosis, is a key health concern during the perimenopause. “Some people on social media argue that fasting could worsen bone loss, but there’s no evidence supporting this theory,” stresses Dr. Adam. “In fact, intermittent fasting seems to be better for bone health than traditional calorie-restricted diets, which might limit calcium intake.”

So is intermittent fasting safe and should you do it?

Overall, Dr. Adam says there’s no strong evidence to suggest that fasting poses risks during menopause, or that one type of fasting (like only eating during certain hours versus the popular 5:2 diet) is better than another.

“The benefits of fasting, such as weight loss and improved metabolism, seem to apply equally well to women during menopause,” he concludes. “However, more studies are needed to fully understand how fasting affects women during this transitional period.”

While intermittent fasting can be an approachable way to stay within a healthy weight range, it might not be right for everyone – particularly if you are taking regular medication or have type 1 diabetes. As with any major health change, it’s always a good idea to run a new eating plan past your GP first, who can help you to weigh up the personal risks and benefits.