“I think my metabolism is broken.” I hear this almost every week. Women who feel like they’re doing everything right - eating less, exercising more - and still not seeing results. And they’ve concluded that something fundamental must be wrong with their body.

Here’s the truth: your metabolism probably isn’t broken. But if you’ve spent years yo-yo dieting, chronically undereating, or pushing your body through punishing exercise routines, it has almost certainly adapted. And that adaptation is the reason the usual advice isn’t working anymore.

The good news? Metabolic adaptation is reversible. But it requires a different approach to the one that caused it in the first place. Not more restriction. Not harder training. Patience, nourishment, and a willingness to trust your body while it heals.

Is your metabolism actually “slow”? What’s really going on

Your metabolism is the sum of all the chemical processes happening inside your body - every heartbeat, every breath, every cell repair, every thought. It’s a vast, complex system, and it’s extraordinarily good at adapting to whatever conditions you give it.

When people say they have a “slow metabolism,” what they usually mean is that their body doesn’t seem to burn energy as efficiently as it once did. And in many cases, they’re right - but it’s not because something is inherently wrong. It’s because their body has adapted to the conditions it’s been given.

The most common causes of metabolic slowdown are:

  • Chronic undereating. Years of eating below your BMR teaches your body to survive on less. It becomes more energy-efficient - which sounds positive but means it burns fewer calories for the same activities.
  • Muscle loss. Muscle is metabolically active tissue - it burns energy even at rest. If you’ve lost muscle through crash dieting, excessive cardio, or simply not doing any resistance training, your metabolic rate has dropped accordingly.
  • Hormonal changes. Perimenopause, thyroid function, chronic stress - all of these affect how efficiently your body processes energy. Hormonal shifts are a legitimate factor, but they don’t mean you’re stuck.
  • Poor sleep. Sleep deprivation directly affects metabolic function, insulin sensitivity, and hunger hormones. Chronic sleep disruption can mimic many symptoms of a “slow metabolism.”
  • Chronic stress. Prolonged cortisol elevation affects fat storage (particularly around the abdomen), disrupts appetite regulation, and impairs your body’s ability to use energy efficiently.

Notice a theme? Most of these aren’t permanent conditions - they’re adaptations to how you’ve been treating your body. Change the input, and the output changes too.

How crash dieting damages your metabolic rate

I’ve covered this in detail in my posts on why diets don’t work and BMR and TDEE, but it’s worth revisiting here because it’s the single biggest factor I see.

Every time you go on a very low calorie diet, your body responds by slowing its metabolic rate. It reduces the energy spent on non-essential functions - digestion slows, body temperature drops slightly, you move less without realising it (fidgeting, pacing, general restlessness all decrease). Your body is simply trying to match its energy output to its input.

When you return to eating normally, your metabolism doesn’t instantly bounce back. It stays suppressed for a period - sometimes a long period, depending on how severe and how prolonged the restriction was. Meanwhile, your body is primed to store fat as efficiently as possible. This is why the weight comes back so fast after a crash diet, and why each cycle typically leaves you a little heavier and a little more metabolically compromised.

After years of this pattern, women often find themselves eating very little but still not losing weight. It’s not that they’re lying about what they eat (though they’re often accused of that). It’s that their metabolism has genuinely adapted to chronic restriction.

Sleep is one of the most underrated tools for metabolic health. Your body rebuilds while you rest.

Muscle and metabolism: why strength matters

If there’s one thing I could convince every woman to do, it would be to start some form of resistance training. Not because I want everyone to look a certain way. But because muscle is the engine of your metabolism, and without it, everything becomes harder.

Muscle tissue burns more energy at rest than fat tissue. The more muscle you have, the higher your basal metabolic rate - meaning you burn more calories just existing. This is why strength training is the single most impactful thing you can do to support your metabolism long-term.

And yet, so many women have spent decades avoiding resistance training. They’ve been told that cardio burns more calories (it does in the moment, but not over time). They’ve been told that weights will make them “bulky” (they won’t - women don’t produce enough testosterone for that). They’ve spent their gym time on the treadmill or the cross-trainer, steadily losing muscle mass while wondering why their metabolism keeps slowing down.

You don’t need to become a powerlifter. You don’t even need a gym. Bodyweight exercises - squats, lunges, press-ups, planks - are a brilliant starting point. Resistance bands, light dumbbells, even carrying heavy shopping bags and playing with your children - all of these build and maintain muscle.

Two to three sessions per week is plenty. If you’re not sure where to start, begin with what feels manageable and build gradually. The goal is consistency, not intensity.

Eating enough to fuel your fire

This is the part that terrifies women who’ve been conditioned to believe that eating less is always better. But if your metabolism has adapted to chronic restriction, the fix is eating more, not less.

This process - sometimes called “metabolic recovery” or “reverse dieting” - involves gradually increasing your food intake back to a level that properly supports your body’s needs. It’s not about bingeing or eating recklessly. It’s about systematically giving your body the fuel it needs to function optimally.

What this looks like in practice:

  • Eat at or above your BMR. This is the absolute minimum your body needs. If you’ve been eating below it, start working back up gradually - adding 100-200 calories per week.
  • Prioritise protein. Protein has the highest thermic effect of any macronutrient - your body uses roughly 20-30% of the energy in protein just to digest it. It also supports muscle building and repair. Aim for a palm-sized portion at every meal.
  • Eat regularly. Consistent meals throughout the day keep blood sugar stable and reassure your body that food is available. Skipping meals tells your body to conserve - which is the opposite of what you want.
  • Don’t fear carbohydrates. Your body needs glucose to function. Complex carbohydrates fuel your brain, your muscles, and your daily activity. Cutting carbs dramatically can further suppress metabolic rate and tank your energy.
  • Include healthy fats. Essential for hormone production - and your hormones govern your metabolism. Olive oil, avocado, nuts, seeds, oily fish. These are non-negotiable.

Will you gain weight initially when you start eating more? Possibly a small amount - your body may retain some water and glycogen as it adjusts. But this isn’t fat gain. It’s your body replenishing stores that were depleted. If you stay consistent, your metabolism will gradually upregulate, and your body composition will improve over time.

Sleep and stress: the hidden metabolism killers

You can eat perfectly and train optimally, but if you’re not sleeping well or you’re chronically stressed, your metabolism will suffer. This is the piece that’s so often overlooked - and it’s one of the most important.

Sleep is when your body does its most significant repair work. Growth hormone - which supports muscle building and fat metabolism - is released primarily during deep sleep. When you don’t sleep well, this process is disrupted. Additionally, poor sleep increases cortisol (promoting fat storage), impairs insulin sensitivity (making it harder for your body to use energy efficiently), and disrupts the hormones that regulate appetite.

Chronic stress keeps cortisol elevated, which has a cascade of metabolic effects: increased fat storage (particularly around the abdomen), disrupted blood sugar regulation, increased appetite and cravings for quick-energy foods, and impaired digestion. Living in a constant state of low-grade stress is metabolically equivalent to running your car engine at high revs but never going anywhere - it uses fuel and causes wear without producing useful output.

Supporting your metabolism means supporting your nervous system:

  • Prioritise 7-9 hours of sleep per night
  • Create a consistent sleep routine
  • Reduce caffeine intake, especially after midday
  • Build daily stress-management practices - breathwork, walking, time in nature, journalling
  • Say no to what drains you where possible
  • Recognise that rest is not laziness - it’s a metabolic investment

Movement that supports metabolism (not just cardio)

If your exercise routine consists solely of cardio - running, cycling, the cross-trainer - you’re missing the most metabolically effective form of movement.

Cardio has its place. It’s brilliant for cardiovascular health, mood, and endurance. But on its own, without resistance training, it doesn’t build muscle. And in excess - particularly combined with undereating - it can actually contribute to muscle loss and metabolic adaptation.

The ideal approach for metabolic health combines:

  • Resistance training (2-3 times per week) - Builds and maintains muscle. This is your metabolism’s best friend.
  • Daily walking - Low-intensity, high-reward. Burns energy without spiking cortisol. Supports blood sugar regulation and mood. Aim for 7,000-10,000 steps as a general guideline.
  • Moderate cardio (if you enjoy it) - 1-2 sessions per week of something you genuinely like. Swimming, cycling, dancing - whatever keeps you moving without running you into the ground.
  • Recovery and flexibility - Yoga, stretching, mobility work. These support your body’s ability to recover and adapt. Don’t skip them.

The biggest shift for many of my clients is realising that more exercise isn’t always better. Training six days a week while eating 1,400 calories isn’t dedication - it’s a recipe for metabolic suppression. Three thoughtful sessions per week with adequate fuel and rest will produce better results than six exhausting ones ever could.

The long game: metabolic recovery takes patience

I won’t pretend this is quick. If you’ve spent years - or decades - undereating and overexercising, your metabolism won’t bounce back in a week. Metabolic recovery is a process that takes months, sometimes longer. And it requires something that the diet industry never asked of you: patience and trust.

Trust that eating more won’t make you “lose control.” Trust that resting more doesn’t make you lazy. Trust that your body, when given what it actually needs, will find its own healthy equilibrium. This is hard, particularly if you’ve spent a lifetime being told that less is more and harder is better.

But I’ve watched it happen time and time again with the women I work with in F.L.A.M.E. Women who were eating 1,200 calories and running four times a week and stuck. Women who started eating more, training smarter, sleeping better, and managing their stress - and watched their bodies transform. Not overnight. Not dramatically. But deeply and lastingly.

Your metabolism isn’t your enemy. It’s been trying to protect you. Now it’s time to give it what it needs to thrive.

If you’ve been told your metabolism is broken, or if you’ve simply felt that nothing works anymore, I hope this has given you a different perspective. The answer isn’t another diet. It isn’t harder training. It’s a fundamental shift in how you nourish, move, rest, and treat your body.

If you’d like support with this - real, personalised guidance on rebuilding your metabolism and finding an approach that works with your body - that’s exactly what F.L.A.M.E is designed for. No quick fixes. Just the science, the support, and the patience to do it properly.