Why Calorie Counting Is Fundamentally Flawed (And What to Focus on Instead)
Every January, the same thing happens.
Calorie counting apps top the download charts. Diet programmes promising “simple maths” flood your social media. Everyone’s suddenly weighing portions and checking labels.
But here’s what no one’s telling you: calorie counting is based on faulty science.
Not just ineffective. Not just difficult to maintain. Fundamentally flawed from the start.
Let me explain.
The Problem With Calories
We talk about “energy” as if it’s one single thing.
But energy actually comes in different forms:
Heat
Electricity
Light
Sound
Kinetic energy (movement)
Chemical energy
And each one is measured differently:
Electricity in volts and amps
Light in lumens
Movement in joules
Sound in decibels
Heat in calories
We don’t use the same unit for everything because each form of energy behaves differently.
This is the problem with nutrition.
A Calorie Only Measures Heat
A calorie is ONLY a measure of heat. That’s it.
Literally: how much energy it takes to raise the temperature of one kilogram of water by one degree Celsius.
Food scientists work this out by burning food in a device called a bomb calorimeter and measuring how much heat it produces.
But here’s the thing: your body doesn’t run on heat.
Your body runs on ATP (adenosine triphosphate) a chemical form of energy that your cells make, use, and recycle constantly.
And ATP is NOT measured in calories because ATP doesn’t work like heat energy.
It’s influenced by complex biochemical pathways, enzymes, hormones, nutrient type, gut bacteria, and metabolic conditions.
So using calories to estimate ATP is like trying to measure electricity with a thermometer.
You’ll get a number, but it’s the wrong tool for the job.
The Three False Assumptions
The “calories in vs calories out” concept assumes three things:
1. That your body extracts energy from food with fixed efficiency
It doesn’t.
ATP production varies wildly depending on:
The type of food you eat
Your individual metabolism
Your gut microbiome
Whether you’re stressed
How well you slept
Your hormonal status
100 calories of broccoli and 100 calories of chocolate produce vastly different metabolic responses in your body, even though they release the same amount of heat when burned in a lab.
2. That ATP production is linear and predictable
It isn’t.
Your hormones, mitochondrial health, stress levels, illness, nutrient status, and even the time of day all change how efficiently your body produces and uses ATP.
Two people can eat the exact same meal and extract completely different amounts of usable energy from it.
3. That metabolism burns energy at a stable rate
It doesn’t.
Your metabolic rate can shift by hundreds, even up to 1,000, calories per day. I’ve seen this in functional testing with clients.
Factors that change your metabolic rate:
Stress
Sleep quality
Hormonal fluctuations (especially in perimenopause)
How much you’ve been restricting calories
Inflammation
Thyroid function
Muscle mass
Your recent eating patterns
Your body is constantly adjusting its energy expenditure based on what it thinks is happening. If it thinks you’re starving (hello, restrictive dieting), it slows everything down to conserve energy.
The 20% Problem
And here’s the kicker that should make you question the whole system:
Food manufacturers have a 20% leeway on the calorie content they declare on labels.
That “300 calorie” ready meal? Could actually be 360 calories. Or 240 calories.
An electrician wouldn’t calculate electrical output using a thermometer, yet that’s effectively what you’re doing when you obsessively track calories.
What Calorie Counting Actually Does
For many people - particularly women - obsessing over calories has backfired spectacularly into:
Binge/starve cycles Restrict all week, lose control at the weekend, feel ashamed, restrict harder, repeat.
A body they hate Constantly fighting against your natural size, never feeling “good enough,” always needing to lose “just a few more pounds.”
Metabolic adaptation Your body becomes more efficient at storing fat and less efficient at burning it, making weight loss progressively harder.
Disordered eating patterns Food becomes numbers, not nourishment. Eating becomes stressful, not enjoyable.
Loss of hunger and fullness cues You stop trusting your body and start trusting an app instead.
Endless misery Spending mental energy calculating, tracking, worrying instead of actually living your life.
What to Focus on Instead
A strong, healthy body you love living in starts with unlearning everything diet culture taught you about food and exercise, and re-learning what your body is telling you instead.
Focus on these instead of calories:
Nutrient density Are you getting enough protein, healthy fats, fibre, vitamins, and minerals? These are what your body actually needs to function.
Blood sugar balance Eating in a way that keeps your blood sugar stable prevents energy crashes, mood swings, and constant hunger. This matters far more than calorie content.
How you feel Energy levels, sleep quality, digestion, mood, hunger and fullness cues - these are your body’s feedback system. Listen to them.
Food quality Where possible, choose whole foods over processed ones. Your body recognises real food and knows what to do with it.
Eating patterns that suit YOU Some people thrive on three meals a day. Others prefer smaller, more frequent meals. Some do well with breakfast, others don’t. There’s no one-size-fits-all.
Enjoyment Food is meant to be pleasurable. Eating should feel good, not stressful. If your approach to food is making you miserable, it’s not working - regardless of what the numbers say.
The Perimenopause Factor
This is particularly relevant for women in perimenopause.
Your hormones are fluctuating wildly. Your metabolism is changing. Your body is adjusting to a new normal.
Calorie counting during perimenopause is like trying to hit a moving target in the dark whilst someone keeps changing the rules.
What worked in your 30s doesn’t work now. And obsessing over calories when your body is already under hormonal stress often makes things worse:
More cortisol (stress hormone)
Worse sleep
More anxiety
Stronger cravings
More stubborn weight
Your body needs support during perimenopause, not restriction.
Trust Your Body
You were born knowing how to eat.
Babies and toddlers are brilliant at intuitive eating, they eat when hungry, stop when full, and don’t give food a second thought.
Then diet culture got hold of you and taught you not to trust yourself.
But your body is still sending you signals. You’ve just been taught to ignore them in favour of external rules and numbers.
Re-learning to tune in and trust yourself is possible. It takes time, especially if you’ve been dieting for years or decades. But it’s so worth it.
What This Means for You
If you’ve spent years, maybe decades, obsessing over calories and it hasn’t given you the body or the relationship with food you want, it’s not because you’re doing it wrong.
It’s because the whole system is flawed.
You’re using the wrong measurement tool for what your body actually needs.
And you deserve better than spending the rest of your life locked in a battle with numbers on labels and apps.
Thanks for reading Catherine Scott Nutrition! This post is public so feel free to share it.
Ready for a Different Approach?
I work with women who are tired of restriction, tired of obsessing over numbers, and ready to actually feel good in their bodies.
If you’re struggling with perimenopause, gut health issues, or exhaustion, and you’re done with calorie counting, I can help you create an approach that actually works for YOUR body.
Book a free 20-minute discovery call: Book Here
No pressure, just a conversation about whether personalised nutritional support could help you break free from diet culture and start actually enjoying food again.
Catherine x
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