Is your body playing tricks on you? What every woman over 40 should know about blood sugar
Written by Christie Amadio, Naturopath BHSc (Nat)
You've been tracking your continous glucose monitor (CGM). You've been doing everything the wellness world says you should do. And some days your body feels like it's running on completely different software than what you were used to.
Exhausted by 3pm, craving sugar like mad, waking at 2am with your mind racing. Gaining weight around your middle despite eating less than you did. Here's the thing nobody tells you: this isn't your body malfunctioning, it's your body shifting into a different operating manual- perimenopause.
Perimenopause is a master reset and like any system upgrade, it comes with a learning curve. Routines that worked brilliantly for years, and what still works for the men in your life, 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, which 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 slumps, sugar cravings, disrupted sleep and brain fog. It may begin in the late 30s, typically the mid-40s and can last around a decade. It responds well to targeted nutrition, resistance training, sleep and stress support.
What is perimenopause, 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. Instead, they show up as energy and mood swings, brain fog, poor sleep and a frustrating inability to manage weight, no matter how hard you try. At the centre of so much of this is blood sugar regulation.
Why does blood sugar become less stable in perimenopause?
Oestrogen does far more than regulate the menstrual cycle. One of its lesser-known roles is helping your cells respond to insulin, the hormone that moves glucose from the bloodstream into cells for energy. When oestrogen fluctuates during perimenopause, your cells become less sensitive to insulin's signals. This leads to insulin resistance, requiring your body to produce more and more insulin just to do the same job.
The result is that blood sugar spikes and dips 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 to keep belly fat off in your 30s may 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 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 2- 4am as your body releases cortisol to correct the imbalance
Brain fog, forgetting words mid-conversation or difficulty concentrating
Strong cravings for sugar, carbohydrates or caffeine
It’s that 3pm crash. The strong need for something sweet after lunch. Waking at night with your mind racing. There is nothing wrong with you! These are just signs that your body needs different support.
What is the gut's role in perimenopausal 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, which has a compounding effect: poorer blood sugar control, increased inflammation, changes in hunger hormones and further disruption to oestrogen metabolism. It is why the generic advice of "eat less, move more" usually fails women at this life stage.
Efficient fat burning metabolism has never been a simple ‘calories in- calories out’ situation, it needs a hormone lens to understand it well. With peri and menopause, this is even more acute.
How to support blood sugar in perimenopause?
The good news is that blood sugar regulation during perimenopause is possible without requiring perfection or extreme measures! It requires understanding what your body needs 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, whole 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 presses, is one of the most effective interventions for improving insulin sensitivity in midlife.
Walk after meals. Even 10 minutes significantly reduces post-meal 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 and time in nature are not optional or luxuries, they are metabolic necessities! Time management and discipline not to skip meals or under-eat is essential.
Feed your gut. Aim for 30 different plant foods per week and include herbs and 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 progress.
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. It 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 2- 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.