If there is one thing that many women I work with put at the top of her list, it is the weight around her middle. It is the thing she cannot make sense of. Nothing has changed in how she eats or how she moves, but suddenly there is this new thickness around her waist that was never there before, and nothing she does seems to shift it. She has tried eating less. Training harder. Pushing through. And the more she pushes, the more stuck it feels. What I always tell these women is the same thing: this is not a willpower problem. Something has genuinely changed inside your body, and until you understand what that is, the old strategies are not going to work.
If you are in your forties or fifties and feel like your metabolism has changed, I want you to know two things. First, you are not imagining it. Real, measurable changes are happening inside your body that affect how you store fat, burn energy, and respond to food. And second, the solution is not what most of the mainstream advice suggests. It is not about eating less or exercising more. It is about understanding the systems that have shifted and working with your body rather than against it.
Your Metabolism Has Not Broken — But It Has Changed
There is a widespread belief that metabolism crashes at menopause. The research tells a more nuanced story. A large-scale study published in Science found that resting metabolic rate actually stays relatively stable between the ages of 20 and 60, only beginning to decline meaningfully after 60 — and even then, the decline is gradual, roughly one per cent per year. So the menopause transition itself is not causing a dramatic slowdown in the number of calories your body burns at rest.
But here is where it gets more complex: while your metabolic rate may not be plummeting, your metabolic health is shifting. Metabolic health refers to how effectively your body uses energy, manages blood sugar, stores fat, and regulates the processes that keep everything running smoothly. And this is where the hormonal changes of perimenopause and menopause have a significant impact.
Oestrogen plays a direct role in insulin sensitivity, in how your body distributes fat, and in mitochondrial function — the energy-producing capacity of your cells. As oestrogen fluctuates and eventually declines, these systems are affected. The result is not necessarily that you are eating too much or moving too little. The result is that the way your body processes what you eat and how it stores energy has fundamentally shifted.
The Insulin Resistance Connection
If there is one concept I wish every woman in midlife understood, it is insulin resistance. It is arguably the most important metabolic change that happens during and after menopause, and it underpins many of the symptoms women struggle with most: stubborn weight gain (particularly around the abdomen), energy crashes, increased cravings, difficulty losing weight despite consistent effort, and an increased risk of type 2 diabetes, cardiovascular disease, and cognitive decline.
Insulin is the hormone that helps move glucose from your bloodstream into your cells, where it can be used for energy. When your cells become resistant to insulin, glucose stays elevated in the blood, your body produces more and more insulin to compensate, and the excess energy gets stored — predominantly as visceral fat around the middle.
Oestrogen helps keep your cells sensitive to insulin. As oestrogen declines, this protective effect weakens. But oestrogen is not the only factor. Poor sleep, chronic stress, a high-sugar diet, low muscle mass, and sedentary behaviour all contribute to insulin resistance. And in midlife, many of these factors tend to converge. Sleep is disrupted by hormonal changes. Stress is often at its peak. And if you have been under-eating or over-exercising in an attempt to manage your weight, you may have lost muscle mass, which further reduces your body’s ability to manage glucose effectively.
The frustrating part is that insulin resistance often goes undetected. A standard fasting glucose test can come back normal while insulin is already elevated. This is why asking for a fasting insulin test, or an oral glucose tolerance test with insulin measurements, gives a much clearer picture of what is happening metabolically. Understanding whether insulin resistance is part of your picture changes everything about how you approach your nutrition, your movement, and your overall strategy.
Why Calorie Restriction Backfires in Midlife
This is something I see over and over again in the women I work with, and it is one of the most important things I can tell you: the standard advice to eat less and exercise more is often counterproductive for women in perimenopause and menopause.
The research on calorie restriction and fasting shows strikingly different outcomes for men and women. In men, calorie restriction and intermittent fasting tend to improve insulin sensitivity, reduce cardiovascular risk markers, and support cellular repair processes like autophagy. In women — particularly women who are also exercising — the picture is often the opposite. Studies have shown that calorie restriction in women can worsen insulin sensitivity, slow thyroid function, increase oxidative stress, and disrupt endocrine function. For women who were already on the edge of metabolic dysfunction, restricting calories actually pushed them further in the wrong direction.
When you combine calorie restriction with exercise, these negative effects are amplified. Your body perceives the combination of low energy intake and high energy output as a threat, and it responds by dialling down metabolic rate, increasing cortisol, suppressing thyroid function, and holding onto fat stores — the exact opposite of what you are trying to achieve.
Here is what is interesting: when you remove the fasting and just exercise with adequate fuelling, everything improves. Cardiovascular risk factors improve. Inflammation decreases. Autophagy increases. Endocrine function works better. The message is clear: your body needs to be fuelled adequately in order to respond well to the stimulus of exercise. Under-fuelling is not a strategy. It is a stressor.
Where Your Fat Is Stored Matters More Than How Much
One of the most visible changes women notice in midlife is a shift in where fat is stored. Even if total body weight has not changed dramatically, many women find that fat has moved from the hips and thighs to the abdomen. This is not cosmetic. It reflects a real change in metabolic function.
Visceral fat — the fat stored deep in the abdominal cavity, around the organs — is metabolically active in a way that subcutaneous fat (the fat under the skin) is not. Visceral fat produces inflammatory molecules, disrupts hormone signalling, and is closely linked to insulin resistance, cardiovascular disease, and cognitive decline. This shift in fat distribution is driven largely by the decline in oestrogen and the relative increase in androgens that occurs with menopause.
This is why body weight alone is not a particularly useful metric in midlife. Two women can weigh exactly the same but have very different health profiles depending on their body composition — how much muscle they carry versus how much visceral fat they have. Waist circumference, body composition assessments, and metabolic markers like fasting insulin, triglycerides, and HbA1c tell a much more meaningful story than the number on the scale.
The Role of Muscle, Mitochondria, and Movement
If insulin resistance is the most important metabolic concept to understand in midlife, then muscle is the most important asset to protect. Muscle is not just about strength and physical function. It is your largest glucose sink — meaning it is the primary place your body sends glucose to be used or stored. More muscle means better insulin sensitivity. Less muscle means your body has fewer places to put glucose, which drives insulin higher and fat storage up.
Women naturally lose muscle mass as they age, and this process can accelerate during and after menopause. But it is not inevitable. Resistance training — lifting weights, using your body weight against gravity, challenging your muscles with progressive load — is one of the most powerful tools available to you in midlife. It builds and maintains muscle, improves insulin sensitivity, supports bone density, reduces inflammation, and has profound effects on mood and cognitive function.
Mitochondria also deserve attention here. These are the tiny structures inside your cells that produce energy. Oestrogen supports mitochondrial function, so as oestrogen declines, your mitochondria can become less efficient. This shows up as fatigue, reduced exercise tolerance, and a general sense of having less energy to get through the day. Movement, particularly a combination of resistance training and higher-intensity cardiovascular work, stimulates the production of new mitochondria and improves the efficiency of the ones you have. Adequate protein, certain micronutrients like CoQ10 and magnesium, and quality sleep also support mitochondrial health.
A Smarter Approach to Metabolism in Midlife
So if calorie restriction and more cardio are not the answer, what is? The approach I take with the women I work with is built around a few key principles.
Prioritise protein. Protein is the most important macronutrient for women in midlife. It supports muscle maintenance and growth, improves satiety so you naturally eat less without feeling deprived, has a higher thermic effect than carbohydrates or fat (meaning you burn more energy digesting it), and helps stabilise blood sugar. Most women are not eating nearly enough. Aim for at least 1.2 to 1.6 grams of protein per kilogram of body weight per day, spread across your meals, with a particular emphasis on having a strong protein source at breakfast and after training.
Stabilise blood sugar. This is not about eliminating carbohydrates. It is about pairing carbohydrates with protein and healthy fats, reducing refined sugars and ultra-processed foods, and eating in a way that keeps blood sugar relatively steady throughout the day. When blood sugar spikes and crashes, insulin spikes with it, cravings increase, energy drops, and the cycle of metabolic dysregulation continues.
Build and protect muscle. Resistance training two to four times per week, with progressive overload, is non-negotiable for metabolic health in midlife. This does not need to be intimidating. It means gradually challenging your muscles to do more over time. If you are new to strength training, start where you are and build. The return on investment is enormous.
Support your mitochondria. Movement, adequate sleep, stress management, and targeted nutrition all contribute to mitochondrial health. CoQ10, magnesium, omega-3 fatty acids, and B vitamins are particularly relevant. So is avoiding the things that damage mitochondria: chronic under-fuelling, excessive alcohol, prolonged high stress, and poor sleep.
Address stress and sleep. These are not optional extras. Chronic stress increases cortisol, which drives insulin resistance, promotes visceral fat storage, disrupts appetite signalling, and impairs recovery. Poor sleep does the same. In midlife, when your hormonal buffer is thinner, the impact of stress and sleep deprivation on your metabolism is amplified. Addressing these two areas often produces more noticeable change than any dietary intervention.
Look at the full picture. If you have been doing everything you can think of and nothing is shifting, it is worth investigating further. Thyroid function, insulin levels, cortisol patterns, nutrient deficiencies, gut health, and inflammatory markers can all play a role in metabolic dysfunction. A systems-based approach that looks at all of these factors together is far more likely to uncover what is driving your symptoms than any single test or intervention in isolation.
The Way Forward
The most important thing I want you to take away from this article is that the metabolic changes you are experiencing in midlife are real, they are explainable, and they are addressable. Your body has not stopped working. It is responding to a genuine shift in hormones, in cellular energy production, and in the way it handles glucose and stores fat. The strategy that worked in your thirties may no longer be the right strategy now, and that is not a reflection of your effort or discipline. It is a sign that your body needs a different approach.
That approach is not about restriction. It is about nourishment, strength, and strategic support. It is about working with the biology of this stage of life rather than fighting against it. And when you get it right, the results are not just physical. They show up in your energy, your mood, your resilience, and your sense of what is possible from here.