Perimenopause and Metabolism: Why Your Body Feels Different After 40
This is often the most confusing stage.
For many women, perimenopause doesn’t announce itself clearly.
Periods may still be regular.
Life is busy.
And yet something feels different.
Energy is less predictable.
Sleep is lighter.
Cravings feel stronger.
Weight gathers in places it never used to.
Often, this is dismissed as ageing or stress.
In reality, it’s usually the point where hormones and metabolism start talking to each other differently.
Perimenopause Is a Metabolic Transition, Not Just a Hormonal One
Perimenopause is often described as a reproductive transition.
But hormonally, it’s much bigger than that.
Oestrogen and progesterone don’t simply decline — they fluctuate.
These fluctuations affect how your body:
Regulates blood sugar
Responds to insulin
Manages stress
Uses and stores energy
This is why so many women feel metabolically “off” long before periods become irregular.
Understanding this connection is central to [metabolic health](LINK TO METABOLIC HEALTH PILLAR) in midlife.
Oestrogen, Insulin, and Blood Sugar Stability
Oestrogen plays a protective role in insulin sensitivity.
It helps muscle and liver cells respond to insulin and supports efficient glucose uptake.
During perimenopause, oestrogen becomes unpredictable — sometimes high, sometimes low — which makes blood sugar regulation less stable.
This often shows up as:
Energy crashes
Stronger cravings
Feeling shaky or irritable between meals
Increased fat storage around the middle
When oestrogen dips, insulin sensitivity tends to dip with it — even if diet hasn’t changed.
This is one of the key reasons insulin resistance becomes more common in midlife.
Progesterone, Stress, and Metabolic Load
Progesterone is calming by nature.
It supports sleep, nervous system regulation, and stress resilience.
As progesterone declines earlier in perimenopause, many women feel more wired, anxious, or restless — especially at night.
This matters metabolically.
Higher stress levels increase cortisol, which:
Raises blood sugar
Increases insulin demand
Encourages fat storage
Disrupts appetite regulation
This is why stress management is not optional in midlife — it’s metabolic support.
I explore this further in [How Stress Hormones Affect Appetite, Cravings, and Weight After 40](LINK TO STRESS / CORTISOL BLOG).
Why Weight Shifts to the Middle in Perimenopause
Abdominal weight gain is one of the most distressing changes women experience.
This pattern isn’t random.
Lower oestrogen shifts fat storage toward the abdomen, where fat tissue can produce small amounts of oestrogen locally.
At the same time, insulin resistance and cortisol make it harder to access stored fat.
This creates the perfect storm:
Weight accumulates centrally
The body becomes more protective
Traditional dieting becomes less effective
This is a metabolic adaptation — not a personal failure.
It’s also why many women experience [weight loss resistance](LINK TO WEIGHT LOSS RESISTANCE PAGE) during perimenopause, even when eating well.
Why “Healthy Eating” Can Still Feel Wrong in Perimenopause
Many women entering perimenopause are eating better than ever.
And yet:
Long gaps between meals worsen energy
Cutting carbohydrates increases cravings
Skipping protein affects satiety
Over-exercising leads to exhaustion
This isn’t because food choices are bad.
It’s because hormonal shifts reduce metabolic tolerance for stress.
This is why a non-diet approach becomes essential — one that prioritises stability over restriction.
I explain this more in [A Non-Diet Approach to Metabolic Health in Midlife](LINK TO NON-DIET BLOG).
What Supporting Metabolism in Perimenopause Actually Looks Like
Supporting metabolism during perimenopause is about working with hormonal shifts rather than fighting them.
That often means:
Eating regularly to stabilise blood sugar
Prioritising protein to support muscle and insulin sensitivity
Including carbohydrates strategically rather than fearing them
Preserving lean muscle through appropriate strength-based movement
Improving sleep and nervous system regulation
Reducing overall physiological stress
When these foundations are in place, insulin sensitivity often improves — and weight regulation becomes easier without force.
Perimenopause Is Not the Time to Push Harder
One of the biggest mistakes women make in perimenopause is trying to apply younger-body strategies to a more sensitive system.
Extreme dieting, excessive cardio, or rigid rules often worsen symptoms — energy drops, sleep worsens, and cravings intensify.
This isn’t because you’re weak.
It’s because your body is asking for a different kind of care.
Supporting hormones supports metabolism.
Supporting metabolism supports hormones.
The Takeaway
Perimenopause is not just about fluctuating periods.
It’s a metabolic transition that changes how insulin, stress hormones, and energy regulation behave.
When you understand this connection, the frustration makes sense — and so does the solution.
You don’t need more control.
You need more support.
If you’re unsure where to start, a [metabolic health assessment](LINK TO SERVICE PAGE) or this [metabolic health quiz](LINK TO QUIZ) can help clarify which systems need the most attention right now.
Midlife isn’t the time to override your body.
It’s the time to listen more closely.