Why Your Body Is Changing During Perimenopause — And What You Can Actually Do About It

Noticing changes in your weight, waist, muscle, energy or body shape during perimenopause? You're not imagining it. Here's what is happening to your body, why your old strategies may stop working, and what you can actually do to support your health through the transition.

There is a moment in perimenopause when you can start wondering what on earth has happened to your body.

Your clothes don't fit the way they used to. Your waist seems to have disappeared. You might be gaining weight despite eating much the same way you always have, or finding that exercise no longer produces the results you expect. Perhaps your muscles don't feel as strong, your recovery takes longer or your body simply feels softer and less familiar.

And because these changes can sometimes seem to happen quite quickly, it's easy to assume you've done something wrong.

Maybe you need to exercise more.

Maybe you need to cut carbohydrates.

Maybe you need to eat less.

Maybe you need to be more disciplined.

I don't think that's a particularly helpful place to start.

Your body is changing because your biology is changing. Perimenopause is a significant hormonal transition, and it happens at the same time as the normal effects of ageing, changes in muscle mass, lifestyle, sleep, stress and activity.

That doesn't mean you are powerless.

Far from it.

It means that the strategy needs to change with the body.

Why does your body change during perimenopause?

Perimenopause is the transition leading up to menopause, when ovarian hormone production becomes more variable and eventually declines. Oestrogen and progesterone don't simply decrease in a straight line; they can fluctuate considerably from one cycle to the next.

Those hormonal changes can influence much more than your period.

During this stage, women may experience changes in sleep, appetite, mood, body composition, menstrual patterns and sexual wellbeing. At the same time, the ageing process itself is beginning to influence muscle mass, bone health and metabolism.

This is why I don't think it is particularly useful to say that every change in your body is “because of hormones”.

It isn't.

But hormones are part of the picture, and the picture is bigger than hormones alone.

Your body is responding to a combination of hormonal changes, ageing, nutrition, movement, sleep, stress and your individual genetics and circumstances.

Understanding that is important because it takes you away from the idea that you simply need to find the perfect diet or exercise harder.

Why are you gaining weight around your middle?

One of the most frustrating changes for women during perimenopause is the shift in where body fat is stored.

You may have spent most of your adult life carrying more weight around your hips and thighs, only to find that your abdomen seems to become a much more stubborn area during your 40s and 50s.

This isn't your imagination.

The menopausal transition is associated with changes in body composition and fat distribution, including an increase in abdominal or central fat. Changes in oestrogen are thought to contribute, but ageing, muscle loss, activity levels, sleep and overall energy balance also matter.

This is why simply trying to “eat less” isn't the complete answer.

If your strategy for dealing with a changing body is to continually reduce your food intake while increasing your exercise, you can end up in a cycle of restriction, hunger, fatigue and frustration.

A better question is:

How can I support a body that is changing?

That is a much more useful question to ask.

Why does it suddenly feel harder to maintain muscle?

Muscle is one of the things I most want women to pay attention to during midlife.

We naturally lose muscle mass as we age, particularly when we aren't regularly challenging our muscles. This process can begin earlier than many women realise, and the menopausal transition can add another layer to the changes occurring in body composition.

This matters for much more than how your arms or legs look.

Muscle helps you maintain strength and physical function. It contributes to glucose disposal and metabolic health, supports your ability to remain active and plays an important role in maintaining independence as you age.

And there is a practical consequence to losing muscle while gaining body fat: your body composition can change even when the number on the scales doesn't move very much.

This is one reason I want women to stop using weight as their only measure of what is happening to their bodies.

How strong are you?

How easily can you carry things?

Can you get up from the floor?

Can you climb a flight of stairs without feeling completely spent?

Can you lift your suitcase into the car?

These are not glamorous measurements, but they tell you something important about your future health.

What can you actually do about muscle loss?

This is one area where you have a very practical tool available to you: strength training.

You don't need to spend hours in the gym, and you don't need to become obsessed with lifting the heaviest weights possible.

What matters is providing your muscles with a regular stimulus that challenges them and gradually progresses over time.

That might involve weights, resistance machines, bands or bodyweight exercises, depending on your starting point and circumstances.

The important thing is that your muscles have a reason to adapt.

And nutrition matters alongside this. Your body needs enough protein and energy to support muscle maintenance and repair.

This is why I don't like the idea of combining aggressive calorie restriction with lots of cardio when a woman is already concerned about losing muscle.

If your goal is to stay strong as you age, your muscles need to be part of the plan.

I've gone into this in much more detail in Why You Need to Get Stronger in Perimenopause, including the connection between strength training, insulin sensitivity, bone health, mood and longevity.

Why does your metabolism seem to have slowed down?

This is one of the most common things I hear from women:

“I haven't changed what I'm eating, but suddenly I'm gaining weight.”

It can certainly feel as though your metabolism has stopped cooperating.

But the explanation is more complicated than simply saying, “Perimenopause slows your metabolism.”

Your total daily energy expenditure is influenced by your body size, muscle mass, physical activity, spontaneous movement and other physiological factors. As we age, muscle mass can decline and activity levels can change, both of which can reduce energy expenditure.

Hormonal changes may also influence body composition and where fat is stored.

The important point is that your metabolism hasn't broken.

You don't need to starve it back into submission.

You need to understand what has changed and adjust your habits accordingly.

That might mean becoming more intentional about strength training, maintaining adequate protein, increasing everyday movement, improving sleep and paying attention to the quality and overall pattern of your diet.

It is much less exciting than a metabolism “hack”.

But it is considerably more useful.

What does insulin sensitivity have to do with your changing body?

Another piece of the puzzle is insulin sensitivity.

Insulin is a hormone involved in regulating blood glucose. Your muscles are an important site for glucose uptake, which is one reason maintaining muscle and staying physically active is so valuable for metabolic health.

Insulin sensitivity can also be influenced by factors such as body composition, physical activity, sleep and diet. The menopause transition may be associated with changes in metabolic health, although the extent varies considerably between women.

This doesn't mean you need to become frightened of carbohydrates.

In fact, I think the fear of carbohydrates that has crept into menopause nutrition is unhelpful.

Your body uses glucose for energy, and carbohydrate-containing foods can provide fibre, vitamins, minerals and other useful nutrients.

Instead of asking:

“How do I eliminate carbohydrates?”

I'd rather you ask:

“What does the whole meal look like?”

A meal containing a source of protein, plenty of vegetables or other high-fibre foods, a quality carbohydrate source and healthy fats will generally provide a very different nutritional experience from eating a highly refined carbohydrate food on its own.

You don't need to demonise one macronutrient to eat well.

What should you eat when your body starts changing?

This is where I return to one of the simplest ideas in my approach to nutrition: crowding in.

I'm not interested in giving women another list of foods they aren't allowed to eat.

You've probably had enough of those.

Instead, I want you to think about the foods you want to make sure you are eating regularly.

Protein.

Fibre.

A wide variety of plants.

Healthy fats.

Wholegrains and other minimally processed carbohydrate foods.

Calcium-rich foods.

Nutrient-dense foods that give your body the raw materials it needs.

When you start crowding those foods into your day, something interesting happens. You naturally create less room for the foods that don't provide much nutritional value.

And you can still eat them.

Because eating well during perimenopause doesn't mean eating perfectly.

It means building a nutritional pattern that supports the body you have now.

If you want to explore this further, my article What to Eat During Perimenopause goes deeper into the role of protein, fibre, gut health and practical nutrition during the transition.

Do you need to eat more protein during perimenopause?

Protein deserves particular attention during midlife because maintaining muscle becomes increasingly important as we age.

Protein provides amino acids needed for the maintenance and repair of body tissues, including muscle. Eating enough protein across the day can also contribute to satiety and make meals more satisfying.

But I don't want you to become obsessed with hitting a magic number.

Your individual protein needs depend on factors such as body size, activity level, age and health status. If you're highly active or doing regular resistance training, your needs may be different from someone who is sedentary.

A useful practical strategy is to include a meaningful source of protein at each main meal, rather than eating very little protein throughout the day and trying to catch up at dinner.

That might be eggs and Greek yoghurt at breakfast, tofu or legumes at lunch, and fish, chicken, lean meat or another protein source at dinner.

Or, if you eat predominantly plant-based, it might mean being more intentional about combining a range of protein-rich plant foods throughout the day.

The goal isn't perfection.

It's consistency.

Why does your body need more than protein?

Protein has become the celebrity nutrient of midlife, but it isn't the whole story.

Fibre is particularly important for digestive health, heart health and satiety, and a high-fibre dietary pattern is associated with a range of health benefits.

Your gut microbiome also benefits from dietary diversity and the different types of fibre found in plant foods.

This is one reason I don't want women to become so focused on protein that their diet becomes essentially chicken, protein yoghurt and protein bars.

Your body needs a variety of nutrients, not just a high protein number.

Vegetables, fruit, legumes, wholegrains, nuts, seeds and other plant foods bring fibre and a wide range of micronutrients and bioactive compounds to your diet.

Think more variety, not more rules.

What is happening to your bones?

While body shape and weight tend to get most of the attention, there is another change happening underneath the surface that deserves far more discussion: bone health.

Oestrogen plays an important role in maintaining bone tissue. As oestrogen levels decline through the menopause transition, bone loss can accelerate.

You cannot see this happening when you look in the mirror.

But it matters.

Bone health is one of the reasons midlife is such an important time to think beyond weight loss and appearance. Your goal should be to arrive in later life with as much strength, muscle and bone health as possible.

Resistance training and weight-bearing physical activity can help support bone health. Adequate calcium and vitamin D are also important, alongside overall nutrition.

If you have risk factors for osteoporosis or concerns about your bone health, speak with your GP about whether you need further assessment.

This is another reason why I want women to think about what their bodies need for the next 30 years, rather than only how their bodies look today.

Why does your sleep suddenly affect everything?

If your body is changing and you're also sleeping badly, it can feel as though everything has become harder at once.

Perimenopause can be associated with sleep disruption, including difficulty falling asleep, waking during the night and early morning waking. Hot flushes and night sweats can contribute, but they aren't the only reasons sleep can change.

And poor sleep doesn't stay neatly in the “sleep” category.

It can affect mood, energy, appetite, concentration, exercise and your ability to cope with stress.

You may find yourself reaching for quick energy foods because you're exhausted. You may skip your workout because you have no energy. You may feel more emotionally reactive. None of this means you lack discipline.

Sometimes you're simply tired.

If you're waking during the night, you may find Perimenopause and Sleep: Why You Can't Stay Asleep and Why You're Waking Up at 3am in Perimenopause useful next reads.

What about stress?

Stress is another factor that can make a changing body feel even harder to manage.

Midlife can be an extraordinarily full stage of life. You may be managing work, children, relationships, ageing parents, finances and a seemingly endless list of things that need your attention.

And when you're already stretched, it is very easy for your own health to move to the bottom of the list.

But stress isn't something you can always “manage away” with a bubble bath and a scented candle.

Sometimes reducing stress means looking honestly at what you're carrying and deciding what can be delegated, delayed, simplified or removed.

It also means recognising that recovery is not laziness.

Your body needs periods of lower demand.

And if you feel as though you're carrying everyone else's life on your shoulders, have a look at The Mental Load of Midlife Women (And Why Perimenopause Can Make It Harder).

What can you actually do about a changing body?

This is probably the question you really want answered.

And thankfully, you don't need a complicated 27-step protocol.

There are a handful of things that have a much better evidence base than chasing the latest menopause “hack”.

1. Prioritise strength

Give your muscles a reason to stay strong. Include resistance training regularly and progressively increase the challenge as you become stronger.

2. Eat enough protein

Include a good protein source at your main meals and consider your overall intake in the context of your size, activity and health.

3. Eat plenty of fibre

Build meals around vegetables, fruit, legumes, wholegrains, nuts and seeds rather than relying on highly processed foods for most of your energy.

4. Keep moving outside your workouts

Exercise is important, but so is everyday movement. Walking, taking the stairs, gardening, housework and simply spending less time sitting all contribute to your overall activity.

5. Protect your sleep

If you're consistently sleeping badly, don't simply accept it as something you have to put up with. Look at what may be contributing and seek professional support when appropriate.

6. Don't ignore your bones

Resistance and weight-bearing exercise, adequate nutrition and appropriate calcium and vitamin D intake all matter. If you have specific risk factors, talk with your healthcare professional.

7. Stop making weight the only goal

Your waist measurement, weight and clothes size can tell you something, but they don't tell the whole story. Strength, fitness, blood pressure, blood lipids, blood glucose, physical function and how you feel are also important markers of health.

8. Give yourself some flexibility

A healthy diet does not require you to eat perfectly every day. The pattern matters far more than whether you had pizza on Friday night.

What about supplements?

This is an area where I think women are often sold far more than they need.

As soon as your body starts changing, there is a supplement, powder or “hormone balancing” product promising to fix it.

I'd be cautious.

Supplements can be useful when there is a genuine nutritional deficiency, increased requirement or specific clinical indication. But they aren't a substitute for adequate food, resistance training, sleep or medical care.

And “natural” doesn't automatically mean effective or safe.

If you're considering supplements for symptoms or health concerns, particularly if you're taking medications or have a medical condition, discuss them with your GP, pharmacist or appropriately qualified health professional.

What if you still want to lose weight?

You don't have to apologise for wanting to lose weight.

I don't think telling women that they should simply “love their bodies” is always realistic or helpful.

If weight loss is appropriate for you, there are ways to approach it without turning your life into a punishment.

The key is to avoid losing sight of the things that become increasingly important during midlife: muscle, bone, nutrition, physical function and psychological wellbeing.

A sustainable approach should help you lose body fat while preserving as much lean mass as possible, rather than relying on extreme restriction and excessive exercise.

And there are circumstances where weight loss may not be the right priority at all.

If you have significant unexplained weight changes or other concerning symptoms, don't assume that everything is due to perimenopause. There are many possible causes of changes in weight and body composition, and your GP can help you work out whether further assessment is appropriate.

You don't have to get your old body back

I think this is the part that can be difficult to accept.

We are constantly encouraged to chase the body we had ten or twenty years ago. There is an entire industry built around convincing women that every sign of ageing is a problem that needs correcting.

But what if that isn't the goal?

What if your job now is not to recreate your 35-year-old body?

What if your job is to build a body that is strong enough, nourished enough and healthy enough to carry you through the next 30 years?

That changes the conversation.

Instead of exercising because you hate your stomach, you can exercise because you want strong legs and a resilient body.

Instead of eating less because you're frightened of gaining weight, you can eat well because you want to protect your muscle, bones, heart and brain.

Instead of viewing sleep as an inconvenience, you can start treating it as part of your health.

Instead of asking, “How do I stop my body changing?”, you can ask:

“How can I help my body change well?”

That is a much more empowering question.

Your body is changing. Now you get to change the strategy.

Perimenopause doesn't mean your health is suddenly out of your control.

It means some of the strategies that worked in your 20s and 30s may no longer be the strategies worth prioritising.

You may need to put more emphasis on strength and muscle. You may need to become more intentional about protein and fibre. You may need to pay more attention to sleep and recovery. You may need to rethink your relationship with dieting and exercise.

And you may need to stop expecting your body to behave exactly as it did twenty years ago.

Your body isn't failing you.

It's asking for a different kind of support.

And the sooner you stop fighting that reality, the sooner you can start working with it.

Where should you start?

You don't need to overhaul everything this week.

In fact, I would strongly advise against it.

Start by working out which part of the picture needs the most attention. Is it your nutrition? Your energy? Your movement? Your sleep? Your stress?

These five foundations are deeply connected, and improving one can make it easier to work on the others.

That's why I created the free Perimenopause Snapshot Assessment.

It takes a few minutes and gives you a clearer picture of where you are right now, so you can stop guessing and identify a practical place to begin.

Take the free Perimenopause Snapshot Assessment →

Frequently Asked Questions

Why is my body changing so much during perimenopause?

Perimenopause involves fluctuating levels of ovarian hormones, particularly oestrogen and progesterone. At the same time, normal ageing can affect muscle mass, activity levels and body composition. Changes in sleep, stress, nutrition and physical activity can also contribute, so body changes during perimenopause usually have more than one cause.

Why am I gaining weight around my stomach during perimenopause?

The menopause transition is associated with changes in body fat distribution, including an increase in abdominal fat for some women. Hormonal changes may contribute, alongside ageing, changes in muscle mass, physical activity, sleep and overall energy balance.

Why am I gaining weight even though I haven't changed my diet?

Your energy needs can change as your body composition, muscle mass, physical activity and other factors change. Sleep disruption and hormonal changes can also influence appetite and eating patterns. This doesn't necessarily mean you are doing anything wrong, and it is worth looking at the whole picture rather than assuming you simply need to eat less.

Does perimenopause slow your metabolism?

Metabolism is influenced by many factors, including body size, muscle mass, physical activity and ageing. The menopause transition can coincide with changes in body composition and energy expenditure, but it is too simplistic to say that perimenopause simply “breaks” or dramatically slows your metabolism.

How can I maintain muscle during perimenopause?

Regular resistance training and adequate protein are important strategies for maintaining muscle as you age. Your overall energy intake, physical activity and recovery also matter. If you are new to strength training, start at an appropriate level and gradually increase the challenge.

How much protein should I eat during perimenopause?

There is no single protein target that is appropriate for every woman. Requirements vary according to factors including body size, age, physical activity and health. Including a meaningful protein source at each main meal can be a practical way to support muscle maintenance.

Should I stop eating carbohydrates during perimenopause?

No. Carbohydrate-containing foods can provide energy, fibre, vitamins and minerals and can form part of a healthy diet. Rather than eliminating carbohydrates, consider the quality and quantity of the overall meal and combine carbohydrate foods with protein, fibre and healthy fats.

Can strength training help with menopause-related body changes?

Strength training can help maintain and build muscle and support strength and physical function. It also provides a stimulus that can benefit bone health and contributes to overall metabolic health. It should be considered an important part of an active lifestyle during midlife.

Can perimenopause affect bone density?

Yes. Declining oestrogen during the menopause transition is associated with increased bone loss. Resistance training and weight-bearing physical activity, adequate nutrition and appropriate calcium and vitamin D intake are important components of bone health. Women with additional risk factors should discuss bone health with their healthcare professional.

Do I need supplements during perimenopause?

Not necessarily. Supplements can be useful when there is a specific nutritional deficiency, increased requirement or clinical indication, but they aren't automatically required because you are going through perimenopause. Discuss supplements with your healthcare professional, particularly if you take medications or have an existing health condition.

Why does my body feel different even though my weight hasn't changed?

Changes in body composition can alter your shape even when your overall weight stays relatively stable. Losing muscle while gaining body fat, particularly around the abdomen, can change how your clothes fit and how your body looks without producing a large change on the scales.

Is it normal to feel frustrated by changes in your body during perimenopause?

Absolutely. Changes in body composition, weight, skin, muscle and physical comfort can affect body image and confidence, particularly when they happen alongside other changes in midlife. You don't have to love every change, but learning to support and respect your changing body can be a more sustainable goal than constantly trying to reverse it.

About Louise

Louise is a nutritionist specialising in women’s nutrition and lifestyle during perimenopause and midlife. Through her programmes, she helps women understand the changes happening in their bodies and build practical nutrition and lifestyle strategies to feel more energised, rested and confident through this stage of life.

Last updated: August 2026