“Is my metabolism just slow?”
I’ve heard that question hundreds of times. And for years, I believed the answer was simple: some people have fast metabolisms, some have slow ones, and you’re stuck with what you’ve got.
Turns out I was completely wrong.
Dr. Andrew Jenkinson — a bariatric surgeon who’s spent decades tracking metabolic patterns — explains that basal metabolism isn’t fixed. It’s a dimmer switch that can vary from 60 watts to 240 watts. Same person. Different metabolic states. That’s a 100% range, and it’s not under your conscious control.
Which raises the obvious question: what’s controlling the dimmer?
Your Metabolism Isn’t Broken — It’s a Dimmer Switch
Basal metabolic rate is the energy you burn just existing. Breathing. Heartbeat. Cell repair. Brain function. It accounts for roughly 70% of your daily energy use.
Most people think it’s fixed based on age, height, and weight. That’s what the calculators tell you. Plug in your numbers, get your daily calorie target, job done.
Wrong.
Jenkinson’s data shows basal metabolism is massively variable. The same person, in different metabolic states, can burn 60 watts at rest or 240 watts at rest. That’s not a rounding error. That’s a fundamental shift in how your body allocates energy.
And here’s the bit that matters: you don’t control it directly. No amount of willpower changes your basal metabolic rate. But the signals you send your brain? Those absolutely do.
What Actually Controls the Dimmer
Your brain is constantly monitoring your environment. It’s asking: “Are we safe? Do we have enough resources? Should we conserve energy or spend it freely?”
The dimmer switch responds to four main signals:
Sleep quality. Poor sleep signals threat. Metabolism drops to conserve energy.
Stress levels. Chronic stress = perceived danger. Brain dims metabolism to prepare for sustained survival mode.
Food quality. Ultra-processed food drives inflammation. Inflamed body = compromised system. Metabolism compensates by slowing down.
Inflammation. Whether from poor food, lack of movement, or chronic stress, inflammation tells your brain something’s wrong. Dimmer switch turns down.
None of this is conscious. You can’t think your way into burning more calories. But you can change the inputs.
Why Your Brain Thinks Dieting IS Famine
Here’s where it gets frustrating.
When you restrict calories through dieting, your brain perceives famine. Doesn’t matter that you’re choosing to eat less. Doesn’t matter that you’ve got plenty of body fat stored. Your primitive survival systems can’t tell the difference between voluntary restriction and actual food scarcity.
Dimmer switch turns down.
You start burning fewer calories at rest. Energy drops. Movement slows. You feel cold. Brain fog sets in. Your body is doing exactly what it’s designed to do: conserve energy during perceived shortage.
This is why people say their metabolism is “broken” after years of dieting. It’s not broken. It’s responding to the signals you’ve been sending. Repeated calorie restriction = repeated famine signals. Brain adjusts accordingly.
The CICO Myth (And Why “Calories Out” Isn’t Fixed)
Yes, energy balance matters. I’m not arguing against physics. If you consume more energy than you burn, you store it. If you burn more than you consume, you use stored energy.
But here’s the problem with “calories in, calories out” as a weight loss strategy: the “out” part isn’t fixed.
It’s dynamic. It responds to how you’re living.
When people say CICO works, they’re technically correct. But when they say it’s just about willpower and tracking, they’re ignoring the dimmer switch. You can white-knuckle your way through a 1,500-calorie diet for weeks, but if your brain perceives famine, your basal metabolic rate drops from 240 watts to 150 watts. You’ve just wiped out your deficit without changing your intake.
That’s not failure. That’s biology.
What I Learned During Extended Fasts
I noticed this pattern during my own extended fasts.
Day 2 always felt sluggish. Energy low. Mental fog. Movement felt harder. Classic dimmer-switch response to perceived shortage.
Day 3, everything shifted. Energy spiked. Mental clarity returned. Ketones kicked in properly. Dimmer switch turned back up.
But here’s the key: I’d spent 6 months building metabolic flexibility first through 16:8 fasting and non-UPF eating. My body had learned it was safe to switch fuel sources. It wasn’t reacting to fasting as famine because I’d taught it fasting was temporary, intentional, and safe.
That’s the difference between chronic restriction (dieting) and strategic fasting with adequate recovery (metabolic training).
Send the Right Signals — Metabolism Follows
Jenkinson’s message is simple: stop trying to override metabolism through willpower alone.
Start sending signals that tell your brain it’s safe to burn energy.
Sleep well. Aim for 7-9 hours consistently. Quality matters more than duration.
Eat real food. Non-UPF choices reduce inflammation. Brain interprets this as safety.
Manage stress. Breathing exercises, walking, time outdoors. Signal to your nervous system that you’re not under threat.
Walk daily. Movement without exhaustion tells your brain you’re healthy enough to be active. That’s a green light for metabolism.
Metabolism adjusts upward when your body feels safe. It’s not about forcing it higher through brutal calorie deficits or excessive exercise. It’s about creating an environment where your brain doesn’t need to conserve energy.
🎯 Key Takeaways
- Basal metabolism varies 60-240 watts — it’s a dimmer switch controlled by environmental signals, not a fixed number based on age and weight.
- Your brain can’t distinguish voluntary restriction from famine — chronic dieting triggers the same survival response as actual food scarcity, slowing metabolism to conserve energy.
- CICO fails long-term because “calories out” is dynamic — willpower alone can’t override your body’s adaptive response to perceived threat.
- The dimmer switch responds to sleep, stress, food quality, and inflammation — change these inputs, and metabolism follows without forcing it through restriction.
- Metabolic flexibility takes time to build — strategic fasting works when your body has learned it’s safe to switch fuel sources, which requires months of consistent signalling, not quick fixes.
Ready to Start Your Own Rhythm Reset?
The four inputs that control your metabolic dimmer switch — sleep, stress, food quality, and inflammation — are the foundation of the Rhythm Reset system.
If you’re tired of fighting your metabolism through restriction, start sending the signals that tell your brain it’s safe to burn energy.
👉 Get the 14-Day Rhythm Reset Guide (free)
💪 Want ongoing support? Join Rhythm Club for £30/month (includes FREE app access, community, and weekly accountability calls)
🔽 Read the Video Transcript
“Is my metabolism just slow?”
“Dr. Andrew Jenkinson — bariatric surgeon who’s seen every metabolic pattern — explains basal metabolism isn’t fixed. It’s a dimmer switch that can vary from 60 watts to 240 watts. That’s a 100% range, and it’s not under your conscious control.” “Basal metabolic rate is the energy you burn just existing. Breathing. Heartbeat. Cell repair. Brain function. It’s 70% of your daily energy use.”
“Most people think it’s fixed based on age, height, weight. Wrong. Jenkinson’s data shows it’s massively variable — same person, different metabolic states, can burn 60 watts or 240 watts at rest.”
“What controls the dimmer? Food quality. Sleep. Stress. Inflammation. Your brain senses environmental signals and adjusts metabolism accordingly. Chronic stress? Brain dims metabolism to conserve energy for perceived threat. Poor sleep? Metabolism drops. Ultra-processed food? Inflammation climbs, metabolism compensates.”
“When you restrict calories through dieting, your brain perceives famine. Doesn’t matter that you’re choosing to eat less — primitive survival systems can’t tell the difference between voluntary restriction and actual food scarcity. Dimmer switch turns down. You burn fewer calories at rest.”
“This is why ‘calories in, calories out’ fails long-term. Yes, energy balance matters. But the ‘out’ part isn’t fixed. It’s dynamic. It responds to how you’re living.” “I noticed this during extended fasts. Day 2, metabolism felt sluggish. Day 3, everything shifted — energy spiked, mental clarity returned. Ketones kicked in. Dimmer switch turned back up. But I’d spent 6 months building metabolic flexibility first through 16:8 fasting and non-UPF eating.” “Jenkinson’s message: stop trying to override metabolism through willpower. Start sending signals that tell your brain it’s safe to burn energy. Sleep well. Eat real food. Manage stress. Walk daily. Metabolism adjusts upward when your body feels safe.”
“Metabolism’s not broken. It’s responding to the signals you’re sending. Change the signals, metabolism follows.”
“Free Rhythm Reset Guide in description — four inputs that control your metabolic dimmer switch.” “Educational only. Not medical advice.”
⚠️ Important: This is educational content based on evidence and personal experience. It is not medical advice. Speak to your GP before making changes to your fasting pattern, diet, or medication.
Questions? Email hello@waymorethanweightloss.com
© 2025 Way More Than Weight Loss. All Rights Reserved.
