Blood Sugar and Perimenopause - Why It Changes and What to Do About It
Written by Catherine Scott, Registered Nutritional Therapist (mBANT rCNHC), specialising in perimenopause, gut health and energy.
You're eating the same things you've always eaten. You're moving your body. Nothing has obviously changed. And yet you're exhausted after lunch, craving something sweet by 3pm, gaining weight around your middle and waking at 3am with your mind racing.
This is one of the most common pictures I see in perimenopause. And one of the most misunderstood.
These aren't random symptoms. They're not signs that you're doing something wrong or that you need to try harder. They're signs that your blood sugar regulation has changed and there's a very specific hormonal reason why.
This post explains what's happening, why it matters and what you can actually do about it.
Why does blood sugar change in perimenopause?
The short answer is oestrogen.
Oestrogen plays a direct role in how your body manages glucose. It supports insulin sensitivity, the process by which your cells respond to insulin and allow glucose to be taken up from the bloodstream into your muscles and tissues for energy. When oestrogen is working well, this process is efficient and blood sugar remains relatively stable.
In perimenopause, oestrogen doesn't simply decline in a straight line. It fluctuates erratically, surging and dropping unpredictably before eventually falling. These fluctuations disrupt insulin sensitivity in ways that can feel completely disproportionate to what you're eating or doing. Research published in Menopause: The Journal of the Menopause Society found that perimenopausal and menopausal women with higher rates of hot flushes also showed greater variability in continuous glucose monitoring readings, suggesting that vasomotor symptoms and blood sugar instability share common hormonal drivers. A 2025 study of nearly 1,000 women confirmed that compared to non-menopausal women, early menopausal women had a significantly higher rate of insulin resistance.
What does blood sugar dysregulation feel like in perimenopause?
Blood sugar dysregulation doesn't always announce itself clearly. It can look very similar to other perimenopause symptoms which is why it often goes unrecognised. Here are the most common signs:
Signs your blood sugar may be dysregulated in perimenopause
• Energy crashes after meals, particularly high-carbohydrate meals
• Afternoon fatigue that hits around 2 to 4pm regardless of how much sleep you got
• Strong cravings for sugar, carbohydrates or starchy foods especially in the afternoon
• Difficulty losing weight despite eating well and exercising, particularly around the abdomen
• Brain fog and difficulty concentrating, especially after eating
• Waking at 3am with a racing mind is often linked to cortisol release in response to blood sugar dropping overnight
• Mood swings and irritability that seem disproportionate to what's happening
• Feeling hungry again soon after eating a meal
• Feeling shaky, anxious or wired between meals
How does insulin resistance affect perimenopause symptoms specifically?
Insulin resistance doesn't just affect your weight and energy. It has a ripple effect across multiple systems that are already under pressure in perimenopause.
Hot flushes
Research suggests that blood sugar instability may worsen hot flushes. Studies show that high insulin levels may trigger mechanisms that increase core body temperature, and that women with greater blood sugar variability report more frequent and more severe vasomotor symptoms.
Sleep
Blood sugar dropping overnight can trigger a cortisol release which wakes you up, often around 2 to 4am. This is one of the most common causes of that classic middle-of-the-night wake-up that many perimenopausal women experience. Stabilising blood sugar through the evening and before bed can make a meaningful difference to sleep quality.
Weight and body composition
As oestrogen declines fat distribution shifts away from the hips and thighs and towards the abdomen. Insulin resistance compounds this. When cells are less responsive to insulin, the body produces more of it and elevated insulin promotes fat storage, particularly visceral abdominal fat. This is why women who haven't changed their diet or exercise habits can find their body composition changing significantly in perimenopause.
Mood and anxiety
Blood sugar fluctuations have a direct and significant effect on mood and anxiety. The brain relies on a steady supply of glucose and when levels drop sharply, it triggers stress hormones including cortisol and adrenaline. For women in perimenopause whose stress response is already more reactive due to declining oestrogen, this can feel like anxiety or mood instability that seems to come from nowhere.
Does HRT help with blood sugar in perimenopause?
Yes, there is good evidence that oestrogen therapy can improve insulin sensitivity in perimenopausal and postmenopausal women.
A major meta-analysis presented at the 2024 Annual Meeting of The Menopause Society reviewed 17 randomised controlled trials with more than 29,000 healthy postmenopausal women and found that hormone therapy significantly reduced insulin resistance across both oral and transdermal routes. A 2024 study published in Diabetes and Metabolism also found that menopausal hormone therapy decreased the likelihood of diabetes development in perimenopausal individuals with prediabetes. This is worth knowing if you're on HRT and still experiencing blood sugar symptoms. HRT is helpful but nutrition and lifestyle remain important alongside it, not instead of it.
What can you eat to stabilise blood sugar in perimenopause?
The good news is that blood sugar regulation responds very well to nutritional intervention. Here are the most evidence-based dietary approaches:
Protein at every meal and especially breakfast
Protein slows the absorption of glucose and reduces the insulin response to a meal. Starting the day with 25 to 30g of protein at breakfast stabilises blood sugar from the very first meal and sets the hormonal tone for the entire day. Women who eat a high-protein breakfast consistently report fewer afternoon cravings, more stable energy and better appetite control.
Fibre at every meal
Dietary fibre slows digestion and the release of glucose into the bloodstream, producing a more gradual and stable blood sugar response. Soluble fibre from oats, legumes, vegetables and fruit is particularly effective. Research published in the journal Menopause found that higher consumption of refined, high-glycaemic carbohydrates was associated with more severe menopause symptoms including hot flushes, mood changes and fatigue while a higher-quality carbohydrate diet rich in fibre was associated with fewer symptoms. Aiming for 30g of fibre daily from a variety of plant foods is one of the most impactful dietary changes you can make in perimenopause.
Pair carbohydrates with protein and fat
Eating carbohydrates alone produces a much sharper blood sugar spike than eating them alongside protein and fat. Rather than avoiding carbohydrates entirely, pairing them with a protein and a fat at every meal produces a more gradual glucose release and a more stable response. A banana alone will spike blood sugar significantly more than a banana eaten with Greek yoghurt and nut butter.
Eat vegetables before carbohydrates
The order in which you eat food affects your glucose response. Starting a meal with vegetables, then protein and fat, then carbohydrates has been shown to reduce the post-meal blood sugar spike significantly compared to eating in the conventional order. This is a simple, low-effort change that doesn't require restricting any foods.
Reduce ultra-processed foods and refined carbohydrates
Ultra-processed foods and refined carbohydrates - white bread, pastries, sugary drinks, processed snacks - produce rapid and sharp blood sugar spikes followed by equally sharp drops. These are the foods most likely to trigger cravings, energy crashes and overeating. In perimenopause when insulin sensitivity is already compromised these foods have a more pronounced effect than they did in your 30s.
A small protein-containing snack before bed
If the 3am wake-up is a consistent problem, a small snack containing protein and fat before bed can help maintain blood sugar stability overnight and prevent the cortisol release that wakes you up. A small handful of nuts, a tablespoon of nut butter or a few slices of cheese are all good options.
What lifestyle factors support blood sugar balance in perimenopause?
Strength training
Muscle tissue is the primary site of glucose uptake in the body. The more muscle you have the more effectively your body can clear glucose from the bloodstream. Strength training two to three times a week improves insulin sensitivity, supports muscle mass which declines as oestrogen falls and is one of the most evidence-based interventions for blood sugar regulation in midlife.
Walking after meals
A 10 to 15 minute walk after eating significantly reduces post-meal blood sugar spikes. Your muscles use glucose for energy during movement which blunts the blood sugar response to a meal. This doesn't have to be a brisk walk, even gentle movement helps.
Sleep
Poor sleep worsens insulin resistance and blood sugar regulation. Even one night of disrupted sleep can meaningfully reduce insulin sensitivity the following day. Prioritising sleep quality is not optional in perimenopause, it's a metabolic necessity.
Stress management
Cortisol, the stress hormone, directly raises blood sugar by triggering glucose release from the liver. Chronic stress in perimenopause (when the stress response is already more reactive) contributes to persistent blood sugar dysregulation. Breathwork, gentle movement, adequate rest and reducing unnecessary stressors are all clinically relevant for blood sugar management, not just for mental health.
Want to understand your blood sugar picture more fully?
A Midlife MOT gives you a thorough 60-minute one-to-one assessment and a personalised plan tailored specifically to your symptoms and lifestyle. Find out more here.
Or if you'd like to start with the foundations, download my free guide: 10 Daily Habits That Work With Your Hormones, Not Against Them.
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Oestrogen plays a direct role in insulin sensitivity - the process by which cells respond to insulin and take up glucose from the bloodstream. As oestrogen fluctuates erratically in perimenopause, insulin sensitivity is disrupted. This makes blood sugar harder to regulate even when diet and lifestyle haven't changed. A 2025 study of nearly 1,000 women confirmed that early menopausal women had a significantly higher rate of insulin resistance compared to non-menopausal women.
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Common signs include afternoon energy crashes, strong cravings for sugar or carbohydrates, difficulty losing weight particularly around the abdomen, brain fog after eating, waking at 3am, mood swings and feeling hungry again soon after a meal. These symptoms can appear even before blood tests show any abnormality.
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Research suggests there is a connection. Studies show that women with greater blood sugar variability report more frequent and more severe hot flushes. High insulin levels may trigger mechanisms that raise core body temperature. Stabilising blood sugar through diet and lifestyle may help reduce the frequency and severity of vasomotor symptoms alongside other interventions.
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The most evidence-based dietary approach prioritises protein at every meal — particularly breakfast — to stabilise blood sugar from the start of the day. Pairing carbohydrates with protein and fat reduces the glucose spike. Eating vegetables before carbohydrates at meals reduces the post-meal blood sugar response. Aiming for 30g of fibre daily supports stable blood sugar and gut health. Reducing ultra-processed foods and refined carbohydrates prevents sharp spikes and crashes.
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Yes. A major meta-analysis presented at the 2024 Annual Meeting of The Menopause Society reviewed 17 randomised controlled trials with more than 29,000 postmenopausal women and found that hormone therapy significantly reduced insulin resistance through both oral and transdermal routes. HRT is helpful for blood sugar regulation but nutrition and lifestyle remain important alongside it.
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The 3am wake-up is often a blood sugar issue. When blood sugar drops overnight the body releases cortisol to raise it again — and cortisol wakes you up. This is compounded in perimenopause by declining progesterone and oestrogen which affect sleep architecture and the stress response. A small protein and fat containing snack before bed, combined with stable blood sugar through the day, can help reduce middle-of-the-night waking.
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Yes! Significantly. Strength training two to three times a week improves insulin sensitivity and supports muscle mass, which is the primary site of glucose uptake in the body. Walking after meals for 10 to 15 minutes meaningfully reduces post-meal blood sugar spikes. Both forms of exercise are evidence-based interventions for blood sugar regulation in midlife and are particularly important as oestrogen declines.
Catherine Scott is a Registered Nutritional Therapist (mBANT rCNHC) based in Leeds, specialising in perimenopause, gut health and energy. She works with midlife women online across the UK.
This article is for educational purposes and is not intended to replace medical advice. Please consult your GP or a registered health professional if you have specific health concerns.