Intermittent Fasting and Menopause: Benefits, Risks and How to Start

What is intermittent fasting?

Intermittent fasting (IF) is an umbrella term for eating patterns that alternate eating and fasting periods. The most common types are:

• Time-restricted eating (TRE): eating within a set window each day, such as 8 or 10 hours, and fasting the rest (for example, "16:8").
• Alternate-day fasting (ADF): eating very little (often about 500 calories) every other day and eating normally on the days in between.
• 5:2: eating normally five days a week and eating very little on two non-consecutive days.

Most of IF's weight effect comes from a simple mechanism: a shorter eating window or fewer eating days usually means fewer calories overall. Some people also find it easier to follow than counting calories.

Why are women in menopause interested in fasting?

The menopause transition changes body composition. In the SWAN study, the rate of fat gain doubled and lean mass started to decline once the transition began (Greendale et al., 2019). Falling estrogen also shifts fat toward the abdomen and can reduce insulin sensitivity. Many women find their old approach stops working and look for something new. Our main guide to menopause weight gain explains these changes in more depth.

Does intermittent fasting work after menopause?

The research specifically in menopausal women is small but fairly consistent: IF seems to work about as well for them as for younger women.

• Time-restricted eating: In an 8-week trial with a 4- to 6-hour daily eating window, premenopausal and postmenopausal women with obesity lost the same share of body weight (about 3.3%). Fat mass, fasting insulin and insulin resistance improved similarly in both groups (Cienfuegos et al., 2021).
• Alternate-day fasting: Pooled data from ADF trials found weight loss of about 6.5% in postmenopausal women, 4.6% in premenopausal women, with no meaningful difference between groups. Notably, people ate about 400 to 500 more calories than prescribed on fast days, a reminder that real life is messier than a protocol (Lin et al., 2021).
• Blood sugar: A 2022 meta-analysis of people with impaired glucose and lipid metabolism reported improvements in some measures of blood sugar, lipids and insulin resistance with intermittent fasting (Int J Endocrinol, 2022).

Comparisons with ordinary calorie reduction generally show similar results. IF is a tool for eating less, not a metabolic shortcut.

By the numbers

Weight loss with fasting in midlife women

~3.3%of body weight lost in 8 weeks of time-restricted eating, pre- and postmenopause alikeSource: Cienfuegos 2021

~6.5%weight loss in postmenopausal women in pooled alternate-day fasting trialsSource: Lin 2021

4.6%weight loss in premenopausal women in the same trialsSource: Lin 2021

Does fasting affect hormones in menopause?

A common worry is that fasting disrupts female hormones. In postmenopausal women in an 8-week TRE study, estradiol, estrone, progesterone, testosterone and SHBG did not change. DHEA, an adrenal hormone, fell by about 13% on average (Kalam et al., 2023). The study was small and short, so it can't rule out longer-term effects.

Claims that fasting "raises cortisol and worsens hot flashes" are common online, but there is little direct evidence either way in menopausal women. If fasting leaves you shaky, irritable, sleeping worse or having more night sweats, that is a good reason to loosen the schedule. Perimenopausal women, whose hormones are still fluctuating, were excluded from these studies, so evidence for that stage is thinner.

What are the risks of intermittent fasting in menopause?

Muscle loss

Muscle loss is already speeding up during the transition. A short eating window makes it harder to reach enough protein, which older adults need more of: at least 1.0 to 1.2 g per kilogram per day, according to one expert panel (Bauer et al., 2013). Plan protein into each meal and pair IF with strength training. See protein and menopause.

Overeating in the window

Some people compensate by eating more when the window opens, which can erase the deficit or lead to an uncomfortable cycle of restriction and bingeing.

Sleep and energy

Going to bed hungry, or eating a very large late meal, can disturb sleep, which is already fragile for many women in midlife.

Who should avoid it or get medical advice first

• Anyone with a current or past eating disorder.
• People with diabetes, especially those on insulin or sulfonylureas, because of the risk of low blood sugar.
• People taking medications that must be taken with food.
• Anyone with low body weight, frailty, or a history of fainting.

Which fasting schedule is best for menopausal women?

How to start intermittent fasting safely

Step by step

Easing into intermittent fasting

1. 1Start with 12 hours overnight.Finish dinner, then don't eat again until 12 hours later. Hold that for a couple of weeks.
2. 2Extend slowly if it's going well.Move to 13 or 14 hours. There's no need to go further unless it feels easy.
3. 3Eat earlier when you can.An earlier eating window tends to fit better with sleep than eating late at night.
4. 4Front-load protein.Break your fast with a protein-rich meal (eggs, Greek yogurt, tofu, fish) and include protein at every meal in the window.
5. 5Keep meals whole-food based.Vegetables, legumes, whole grains and healthy fats make the window more satisfying. See the menopause belly fat diet for ideas.
6. 6Hydrate.Water, plain tea and black coffee are fine during the fast.
7. 7Keep lifting.Two to three resistance sessions a week help protect muscle.
8. 8Check in with yourself.If sleep, mood, hot flashes or your relationship with food get worse, ease back or stop.

Intermittent fasting vs keto: which is better for menopause?

Both can work, and both work mainly by reducing calories. IF limits when you eat; keto limits what you eat. IF is usually easier to combine with a balanced, Mediterranean-style diet. Keto is more restrictive and can raise LDL cholesterol for some people. Read keto and menopause for the details.

When symptoms are the bigger problem

Fasting won't fix hot flashes, night sweats or menopause-related insomnia, and those symptoms can make any eating plan harder to follow. If they're disrupting your life, it's worth talking to a clinician about treatment. Hormone therapy is the most effective treatment for hot flashes and night sweats; it isn't a weight-loss treatment. Amie HRT+ is a compounded estradiol and progesterone cream, not FDA-approved, prescribed only after a licensed clinician reviews your history and decides it is appropriate. FDA-approved hormone products and non-hormonal options are also available through your own doctor.

The bottom line