Is Your Body Playing Tricks on You? What Every Woman Over 40 Needs to Know About Blood Sugar
Written by Christie Amadio, Naturopath BHSc (Nat)
You've been tracking your CGM. You've been doing everything the wellness world told you to do. And some days your body still feels like it's running on completely different software than it used to.
Exhausted by 3pm. Craving sugar like your life depends on it. Waking at 2am with your mind racing. Gaining weight around your middle despite eating less than you ever have. Here's the thing nobody tells you: this isn't your body malfunctioning. It's your body asking for a different operating manual.
Perimenopause is a master reset and like any major upgrade, it comes with a learning curve. What worked brilliantly for years, and what still works for the men in your life, simply runs on different rules now. Working hard but getting no results isn't a willpower problem. It's a biology update you haven't been taught to work with yet.
Quick Answer
Falling and fluctuating oestrogen during perimenopause reduces your cells' sensitivity to insulin. This is insulin resistance, and it means your body needs to produce more insulin to move the same amount of glucose out of your bloodstream. The result is more frequent blood sugar spikes and crashes, increased fat storage around the abdomen, energy crashes, sugar cravings, disrupted sleep and brain fog. It typically begins in the late 30s to mid-40s and can last around a decade. It responds well to targeted nutrition, resistance training, sleep and stress support.
What Is Perimenopause and When Does It Start?
Perimenopause is the hormonal transition leading up to menopause. It can begin as early as the late 30s and lasts around 10 years. Most women do not realise they are in it until they are well into it, because the symptoms rarely announce themselves as hot flushes and missed periods. More often they arrive as energy crashes, mood swings, brain fog, poor sleep and a frustrating inability to manage weight, no matter how hard you try. And at the centre of so much of this is blood sugar.
Why Does Blood Sugar Become Less Stable in Perimenopause?
Oestrogen does far more than regulate your menstrual cycle. One of its lesser-known roles is helping your cells respond to insulin, the hormone that moves glucose from your bloodstream into your cells for energy.
When oestrogen fluctuates during perimenopause, your cells become less sensitive to insulin's signals. This is called insulin resistance, and it means your body produces more and more insulin just to do the same job.
The result is that blood sugar spikes and crashes become more frequent, and your body starts holding onto fat, particularly around the abdomen and waist, because elevated insulin is a powerful fat storage signal. The eating patterns that worked perfectly in your 30s may suddenly stop working entirely.
As Dr Stacy Sims, female physiology expert, puts it: women are not small men. The hormonal environment of perimenopause shifts the rules entirely.
What Does Unstable Blood Sugar Actually Feel Like?
Once you understand what blood sugar instability feels like from the inside, you will start recognising these experiences as physiological signals rather than personal failings.
When blood sugar is too high, you might notice:
A brief energy surge followed by a heavy crash
Difficulty concentrating, a kind of mental fuzziness
Increased thirst, headaches or a flushing sensation
When blood sugar drops too low, you might experience:
Sudden intense hunger that feels urgent and frantic
Shakiness, heart palpitations or sweating
Irritability or anxiety that comes out of nowhere
Waking between 2am and 4am as your body releases cortisol to correct the imbalance
Brain fog, forgetting words mid-conversation or struggling to concentrate
Strong cravings for sugar, carbohydrates or caffeine
That 3pm crash. The desperate need for something sweet after lunch. Waking at night with your mind racing. These are not signs that something is wrong with you. They are signs that your body needs different support.
What Is the Gut's Role in Perimenopause Blood Sugar Control?
Your gut microbiome, the ecosystem of trillions of bacteria living in your digestive tract, plays a surprisingly large role in how your body manages blood sugar, oestrogen and appetite.
A specific group of gut bacteria called the estrobolome is responsible for metabolising and recycling oestrogen. When this system is healthy, it helps keep hormones more balanced.
During perimenopause, microbial diversity decreases, and this has a compounding effect: poorer blood sugar control, increased inflammation, changes in hunger hormones and further disruption to oestrogen metabolism. It is why a generic "eat less, move more" approach often fails women at this life stage entirely.
How Can You Support Blood Sugar in Perimenopause?
The good news is that blood sugar regulation during perimenopause is something you can actively support. It does not require perfection or extreme measures. It requires understanding what your body needs right now at this stage of life and implementing some changes.
Prioritise protein in the morning. Aim for 30 to 40g at your first meal, ideally within 30 to 60 minutes of waking. This stabilises blood sugar from the start and significantly reduces cravings throughout the day.
Build your plate around fibre. Aim for 25 to 30g daily from vegetables, legumes, flaxseed, chia seeds and berries. Fibre slows glucose absorption and feeds the gut bacteria that support oestrogen metabolism.
Include healthy fats. Avocado, olive oil, nuts, seeds and oily fish slow the absorption of carbohydrates and help keep blood sugar steady between meals.
Choose your carbohydrates wisely. Low-glycaemic whole food sources like sweet potato, oats, quinoa and legumes are your allies. Pair them with protein and fat and avoid eating them alone on an empty stomach.
Lift weights. Muscle is your most powerful blood sugar regulating organ. Resistance training at least three times per week, focusing on compound movements like squats, deadlifts and pressing, is one of the most effective interventions for improving insulin sensitivity in midlife.
Walk after meals. Even 10 minutes significantly reduces post-meal blood sugar spikes by drawing glucose into your muscles.
Protect your sleep. A single night of poor sleep worsens insulin resistance the following day. A consistent bedtime, a cool bedroom and reducing alcohol make a meaningful difference.
Manage cortisol. Cortisol directly raises blood sugar and the cortisol response becomes more pronounced during perimenopause. Rest days, breathwork, time in nature and not under-eating are not optional extras. They are metabolic necessities.
Feed your gut. Aim for 30 different plant foods per week and include fermented foods like sauerkraut, kimchi or kefir regularly. A diverse microbiome is a more effective blood sugar partner.
You're Not Imagining It
If you have read our last piece on biohacking versus adaptive therapy, you will recognise the pattern here. Blood sugar regulation in perimenopause is not about hacking your way through a plateau with more data or more discipline. It is about understanding the new system you are operating and giving it what it actually needs, the same adaptive principle at the heart of everything from mitochondrial health to hormone balance.
Small, consistent changes made with an understanding of your actual hormonal picture can produce results that feel almost miraculous after months or years of trying and not seeing any movement.
Understanding your blood sugar and what your body needs right now is one of the most powerful things you can do for yourself in this season of life. And that changes everything.
Frequently Asked Questions
Why do I crave sugar so much in perimenopause? Falling oestrogen reduces insulin sensitivity, so blood sugar swings become more frequent and more extreme. Sugar and carbohydrate cravings are often your body's response to a blood sugar crash rather than a lack of willpower.
Why do I wake up at 2am during perimenopause? When blood sugar drops overnight, the body releases cortisol to bring it back up. This cortisol surge can wake you between 2am and 4am, even when you fall asleep easily.
Why am I gaining weight around my middle in perimenopause even though I'm eating less? Elevated insulin, driven by reduced insulin sensitivity, is a powerful fat storage signal, and it tends to direct fat storage toward the abdomen. This can happen independently of how much you are eating.
What foods help stabilise blood sugar in perimenopause? Protein at breakfast, 25 to 30g of fibre daily, healthy fats and low-glycaemic carbohydrates paired with protein and fat all help slow glucose absorption and reduce spikes and crashes.
Does exercise help with perimenopause blood sugar issues? Yes. Resistance training at least three times per week improves insulin sensitivity, since muscle is one of the body's most effective sites for clearing glucose from the blood. A short walk after meals also reduces post-meal spikes.