Key Takeaways
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Your metabolism naturally slows with age due to changes in muscle mass, hormone levels, and cellular efficiency — but it’s not irreversible.
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Building muscle, eating enough protein, and staying active are powerful ways to support a healthy metabolism at any age.
- Scientific research shows you can optimise your metabolism through small daily choices — no fad diets or magic pills required.
Did you know that your metabolism actually stays remarkably steady from your 20s into your 60s — until around age 60 when it begins to decline more noticeably? That’s right. A 2021 study published in Science debunked the myth that your metabolism drops off steeply in middle age (R).
Your metabolism is the process your body uses to convert food into energy. This energy fuels everything from your heartbeat to your brain activity. While it’s true your metabolic rate slows over time, there are several reasons for that shift — and more importantly, many ways to stay ahead of it.
Let’s unpack why metabolism changes as we age and what you can do to keep it healthy.
How Your Body’s Metabolism Changes with Age
You may feel like your body doesn’t “burn off” that second slice of pavlova quite like it used to — and you’re not imagining it. But it’s not because your age is working against you. It’s how your body composition changes with time.
As you grow older, muscle mass tends to decline — a process called sarcopenia. From about age 30, you can lose 3–8% of muscle mass per decade (R). Because muscle is more metabolically active than fat, meaning it burns more calories even at rest, losing muscle means your body uses less energy.
At the same time, your mitochondria — the energy-producing units in your cells — become less efficient. That can reduce the energy your body burns and slow down your basal metabolic rate (BMR).
Another factor is non-exercise activity thermogenesis (NEAT), which includes things like walking to the letterbox, gardening, or fidgeting. NEAT tends to decrease as we get older, especially in retirement years, which subtly slows metabolism further (R).
But here’s the good news: you can counter all of these effects with the right lifestyle shifts. Let’s take a closer look.
Hormonal Changes and Their Impact on Metabolism
You might be surprised to learn that hormone levels play a major role in your metabolic pace. And no — it’s not all about oestrogen or testosterone. As you age, levels of growth hormone, thyroid hormones, and insulin can shift. Growth hormone, for instance, helps stimulate muscle repair and fat metabolism. Lower levels can make it easier to gain fat and harder to maintain muscle (R).
Thyroid function also subtly changes with age. Even slightly underactive thyroid activity can contribute to fatigue, weight gain, and reduced metabolic rate. On top of that, older adults can become more insulin resistant, meaning the body doesn’t respond to insulin as effectively. This makes it harder to regulate blood sugar and can lead to fat storage — especially around the middle (R).
However, staying active, eating a protein-rich diet, and managing stress can help support balanced hormones and a steady metabolism.
Why Muscle is Your Metabolism’s Best Friend
One of the most powerful ways to support a healthy metabolism is to build and maintain lean muscle. Muscle tissue burns about three times more calories than fat — even when you’re simply relaxing on the couch.
Strength training isn’t just for bodybuilders. Just two to three sessions per week can help you maintain functional strength, mobility, and a robust metabolism. A 2019 study found that older adults who participated in resistance training experienced significant increases in resting metabolic rate (R).
Plus, strength training helps improve insulin sensitivity, boosts bone density, and supports mental health. Not bad for a couple of sessions with some dumbbells or resistance bands.
The Surprising Role of Nutrition in Metabolic Health
You might think eating less is the solution to a slower metabolism — but in fact, eating too little can backfire.
When your body senses an energy shortage (such as skipping meals or drastically cutting calories), it slows metabolism to conserve energy. This can lead to a frustrating cycle of plateaued weight and fatigue (R).
Eating enough protein is particularly important. Protein not only helps build and maintain muscle, but it also has a higher thermic effect — meaning your body uses more energy to digest it. A diet rich in protein can increase your metabolic rate by up to 15% (R).
Look to include lean meats, eggs, dairy, legumes, nuts, and seeds in your meals. Also, make sure you’re getting enough micronutrients like iron, B vitamins, and magnesium — which are essential for cellular energy production (R).
Movement is Magic for a Metabolic Boost
You don’t need a gym membership to boost your metabolism. Staying active throughout your day is key — and that includes both exercise and non-exercise movement.
Incorporating walking, gardening, stretching, and even playing with the grandkids can contribute to NEAT and keep your metabolism ticking. Every bit of movement counts.
Structured exercise also plays a role. High-intensity interval training (HIIT) has been shown to improve mitochondrial function in older adults (R). But even regular brisk walks can reduce fat, preserve muscle, and enhance metabolic health.
And don’t forget hydration. Dehydration can slow down your metabolism and affect energy levels. Aim for around 2 litres of water per day, more if you’re active (R, R).
Lifestyle Habits That Keep Your Metabolism Burning
Your daily habits have a bigger impact on your metabolism than your birth year. Prioritising quality sleep, reducing chronic stress, and keeping consistent meal timing all support a healthier metabolic rhythm.
Lack of sleep can disrupt appetite-regulating hormones like ghrelin and leptin, making you feel hungrier and less satisfied. Chronic stress raises cortisol, which encourages fat storage and muscle breakdown.
Small rituals — like morning sunlight, winding down before bed, and eating meals at regular times — help reset your body’s internal clock and support metabolism in subtle but powerful ways.
Ageing Gracefully Includes a Thriving Metabolism
Your metabolism may slow naturally, but you have plenty of tools to keep it lively. Through smart nutrition, daily movement, muscle-building habits, and a healthy mindset, you can support your body’s engine for years to come.
There’s no need for drastic diets or punishing workouts. A balanced, joyful approach can help you feel energised, strong, and confident — no matter your age.
Keen to discover more ways to keep your body humming and your health thriving as you age? Read our next blog: Dispelling Common Myths About Metabolism for Weight Loss.
