Intermittent Fasting for Women: What Changes During Perimenopause and Menopause?

If you have reached midlife and your usual eating routine no longer feels quite right, intermittent fasting can sound appealing. A clear eating window offers a simple rule at a time when sleep, energy and symptoms may feel unpredictable.

But is it a useful option during perimenopause or after menopause?

Intermittent fasting may suit some women, but research has not established a single ideal fasting window for this life stage. It should not be presented as a proven treatment for menopausal symptoms or a way to “balance hormones”.

The practical question is whether your eating pattern leaves you adequately nourished, able to exercise, sleeping reasonably well and comfortable around food.

A longer gap between meals is not automatically a better result.

What Is Intermittent Fasting?

Intermittent fasting describes eating patterns that alternate periods of eating with periods of little or no energy intake.

One common version is time-restricted eating, where meals fit within a daily window. A 16:8 pattern, for example, means an eight-hour eating window and a 16-hour fasting window.

Other approaches, including the 5:2 diet, restrict intake on particular days. These are different interventions, so findings from one schedule cannot automatically be applied to another. Dietitians Australia: intermittent fasting

Multi-day fasting and fasting-mimicking diets also need to be considered separately. This article focuses on everyday meal timing rather than prolonged restriction.

What Changes During Perimenopause and Menopause?

During perimenopause, ovarian hormone levels fluctuate and periods often become less predictable. After menopause, oestrogen and progesterone generally remain at lower levels.

Natural menopause is confirmed after 12 consecutive months without a period when there is no other explanation. Hormonal contraception and some medical treatments can make this harder to identify from bleeding patterns alone. Australian Government: menopause

Hot flushes, night sweats, disrupted sleep, mood changes and difficulty concentrating can occur through the transition. Experiences vary considerably.

These changes matter when choosing an eating routine. Delaying breakfast might feel manageable one day and unhelpful after a disrupted night or before an early exercise session.

However, hormonal changes do not establish that every woman should fast for a particular number of hours.

For a broader overview, read Menopause, Perimenopause & Healthy Ageing.

What Does the Research Actually Show?

There is human research involving postmenopausal women, but menopause-specific conclusions remain limited. Much of the evidence concerns weight or blood markers in adults with obesity.

Small Studies Do Not Establish an Ideal Menopause Schedule

A 2021 secondary analysis compared 13 premenopausal and 19 postmenopausal women with obesity during an eight-week time-restricted eating study.

Both groups lost approximately 3% of their starting body weight.

However, the eating windows were only four or six hours long, and perimenopausal women were excluded. This small, short analysis does not establish those restrictive windows as suitable recommendations for women in midlife. The premenopausal and postmenopausal comparison

Hormone Measurements Are Different From Symptom Relief

A 2024 analysis came from a 12-month trial involving 90 adults with obesity, including men and women.

It compared an eight-hour eating window, daily calorie restriction and a control group. Researchers found no significant between-group changes in selected circulating sex hormones. Oestradiol, oestrone and progesterone were assessed in postmenopausal women only.

These findings concern particular blood measurements. They do not demonstrate that fasting restores menopausal hormone levels, improves hot flushes or suits every woman. The sex-hormone analysis

A Shorter Eating Window Does Not Guarantee More Weight Loss

In a separate 12-month trial involving 139 adults with obesity, adding an eight-hour eating window to calorie restriction did not produce significantly greater weight loss than calorie restriction alone.

This was not a menopause-specific study, but it challenges the idea that restricting eating hours necessarily adds a benefit. New England Journal of Medicine: calorie restriction with or without time-restricted eating

Taken together, these studies support treating fasting as one possible way to organise eating—not a universal menopause prescription.

Does Intermittent Fasting Balance Oestrogen?

The studies discussed here do not establish fasting as a way to restore or “balance” oestrogen during menopause.

Unchanged hormone measurements in a trial are not evidence of symptom treatment. Similarly, weight loss does not demonstrate that the underlying menopausal transition has been corrected.

If symptoms are affecting sleep, work, relationships or everyday functioning, discuss them with your GP. Nutrition can support wellbeing, but fasting should not delay appropriate menopause care.

Is There an Ideal Eating Window During Menopause?

Research has not established one ideal window specifically for perimenopausal or postmenopausal women.

Start with your existing routine:

• When do you feel hungry?
• When do you exercise?
• Can you eat proper meals during the working day?
• Are you meeting your nutritional needs?
• Does your routine support sleep and social meals?

Finishing dinner at 7 pm and eating breakfast at 7 am already creates a 12-hour overnight gap. That is an example of meal timing, not a proven menopause treatment or a target everyone needs to follow.

Before making the gap longer, ask whether you would lose a meal that currently helps you eat well.

There is no requirement to progress from 12 hours to 14, then 16. A regular three-meal pattern may fit your life better.

Our guide to Fasting & Healthy Ageing: Why Longer Isn’t Always Better as We Get Older explores the wider nutritional considerations.

Protect Nutrition Before Compressing Your Meals

An eating window does not tell you whether your diet provides enough energy, protein, fibre or essential nutrients.

Keep Useful Opportunities to Eat Protein

Protein supports muscle maintenance and many other body functions. Individual needs vary with body size, activity, age and health.

Include protein foods across your meals, such as:

• Eggs.
• Yoghurt and other dairy foods.
• Fish and seafood.
• Chicken and lean meat.
• Tofu and tempeh.
• Beans, chickpeas and lentils.

Skipping breakfast can remove one convenient protein opportunity. If you do skip it, consider whether the remaining meals comfortably provide enough food.

You do not automatically need a supplement or the same gram target as someone else. An Accredited Practising Dietitian can assess your individual needs.

Read more in Protein Throughout Life: Why Your Protein Needs Change With Age.

Leave Room for Calcium and Food Variety

Alongside protein, include vegetables, fruit, wholegrains, legumes, unsaturated fats and calcium-rich foods.

Milk, yoghurt, cheese and suitable calcium-fortified alternatives can contribute to calcium intake.

Bone health deserves particular attention around menopause, including adequate calcium, vitamin D and appropriate physical activity. A compressed eating schedule should not crowd out these priorities. Jean Hailes: looking after yourself around menopause

Notice When the Window Makes Eating Harder

A shorter schedule may mean rushing lunch, missing food when meetings run late or eating beyond comfort at dinner.

If that happens, make more room for meals.

An afternoon snack may be more useful than trying to fit the day’s nutrition into two hurried sittings.

Give Sleep, Stress and Exercise Equal Attention

Meal timing is only one part of a midlife routine.

If poor sleep is a major problem, extending a fast should not become the main response. Persistent night sweats, insomnia or other disruptive symptoms deserve assessment and a discussion of treatment options.

Arrange meals around the activities you want to sustain. If you train early and feel weak or distracted without breakfast, allow yourself to eat.

Regular movement, including suitable resistance and weight-bearing activities, also matters for muscle and bone health. Jean Hailes: bone health

On demanding days, flexibility may be more useful than enforcing an identical schedule. Needing breakfast or an extra snack is information about your needs.

What Can Nourishing Meals Look Like?

These ideas are for ordinary eating days. Adjust portions to your appetite, activity and individual requirements.

Broth & Co bone broth can provide a savoury base for soups or broth-cooked grains. Build the meal around it with substantial protein foods, vegetables and a grain or other starchy food.

A cup of broth alone is not nutritionally equivalent to a complete meal. Collagen should also not replace varied dietary protein.

For cooking inspiration, explore our Vegetable Forward Soups and Broths.

When Is Fasting Unsuitable—or Something to Discuss First?

Avoid starting intermittent fasting during pregnancy or breastfeeding. Pregnancy remains possible during perimenopause.

If you have a current or previous eating disorder, seek professional advice rather than introducing restrictive eating rules.

Speak with your treating team before changing meal timing if you:

• Have diabetes, particularly when using insulin or medicines that can cause low blood glucose.
• Take medicines with food or at meal-related times.
• Are underweight or losing weight unintentionally.
• Have poor appetite, frailty or difficulty eating enough.
• Are undergoing medical treatment or following a prescribed diet.

Do not change medicine doses or timing yourself to fit a fasting window. Dietitians Australia: suitability and precautions

How Can You Tell Whether Your Routine Needs Changing?

Pay attention to how you function, as well as the quality of your meals.

Reconsider the schedule if it repeatedly leaves you:

• Dizzy or unusually weak.
• Unable to concentrate.
• Struggling to exercise or recover.
• Hungry enough to disturb sleep.
• Preoccupied with food.
• Eating in a way that feels out of control.
• Unable to fit in adequate meals.

Stop fasting if it makes you unwell and seek advice for persistent symptoms. People with diabetes should follow their agreed monitoring and low-blood-glucose treatment plan. International Diabetes Federation: fasting

Do not assume every new symptom is caused by menopause or needs a stricter diet. Your GP can assess other explanations.

Frequently Asked Questions

Do Women Need a Different Fasting Window After Menopause?

There is no established ideal window specifically for postmenopausal women. Health, nutritional needs, medicines, activity and tolerance are more useful considerations than a universal age-based rule.

Can Intermittent Fasting Improve Hot Flushes?

The studies discussed here do not establish fasting as a treatment for hot flushes. Seek advice about evidence-based menopause care if symptoms are troublesome.

Do I Have to Skip Breakfast?

No. Breakfast can provide protein, fibre and other nutrients. If it supports your morning, there is no need to remove it to follow a popular schedule.

Is a 16-Hour Fast Better Than a 12-Hour Overnight Gap?

Not necessarily. Longer restriction can make adequate eating harder, and the research does not establish a universal menopause-specific advantage.

Can I Have Bone Broth or Collagen During a Fast?

Both provide nutrients and energy, so they do not fit a water-only or zero-energy fast.

A fasting-mimicking programme has its own formulation and instructions. Ordinary broth or collagen should not be assumed to fit that protocol.

For more context, read Fasting-Mimicking Diets Explained.

Can I Support My Health Without Fasting?

Yes. Adequate nourishment, varied meals, physical activity, sleep and appropriate healthcare remain useful priorities whether or not you restrict eating hours.

The Takeaway: Choose a Routine That Supports You

Intermittent fasting is optional during perimenopause and menopause.

Some women find an eating window convenient. Others do better with regular meals and snacks. Neither experience creates a universal rule.

Choose a routine that leaves room for adequate nutrition, movement, sleep and everyday enjoyment. If a schedule makes those things harder, changing it is a sensible response.

References

1. Dietitians Australia: Intermittent fasting
2. Australian Government: Menopause
3. Time-restricted eating in premenopausal versus postmenopausal women, 2021
4. Time-restricted eating, calorie restriction and sex hormones, 2024
5. Calorie restriction with or without time-restricted eating, 2022
6. Jean Hailes: Looking after yourself around menopause
7. Jean Hailes: Bone health
8. International Diabetes Federation: Fasting

This article provides general information and does not replace personalised medical or dietetic advice. Consult your healthcare professional before changing eating patterns if you have medical conditions, take medicines or have concerns about nutritional adequacy.