The science behind Nico

The control room

Somewhere in your body, a room full of workers is dealing with what you had for breakfast.

The cast

Insulin is the one who tidies. When sugar arrives, her job is to get it out of the blood and into a cupboard, and she will not rest until it is done.

The Liver runs the first cupboard. He is quiet, uncomplaining and close to the door, so he gets handed the first load of everything.

Fat runs the big store at the back. He is packed full, warm-hearted and desperate to be useful.

The Muscles are the biggest crew in the building, and the only ones who can take sugar out of the room.

The Mitochondria are the furnaces. There are about a thousand in every room in the body, and they are happiest with a small, even flow of fuel.

The Brain lives upstairs and is not in the room.

The Line is the glowing thread across the control room screen. It shows how much sugar is in the blood.

Act one. The flood

It is early morning. The Line is flat. The Mitochondria hum along, burning the fuel Fat passes them from the store, and Insulin has her feet up.

Then breakfast arrives, and it arrives as a flood. Sugar pours through the door, eight teaspoons of it, into a room built to hold one. The Line leaps up the screen.

Insulin is on her feet at once. "Liver, take this." The Liver's cupboard fills in minutes. "Fat, the rest is yours." She sweeps the surplus into the big store and slams the door behind it. "Nothing comes out while I'm working. House rule."

She glances at the Muscles, who have not moved since the alarm went off, and knocks on their door. They take a little, slowly, because nobody has asked anything of them since yesterday.

Fat presses his face to the glass. "I've got plenty in here. Shall I pass some out?"

"Door stays shut."

At the furnaces, the Mitochondria are swamped. Too much fuel, too fast. The flames roar, smoke curls up to the ceiling, and the room grows uncomfortably warm.

Act two. The dip

In her rush, Insulin tidies away too much. The Line sails past where it started and keeps falling. The lights dim. The furnaces sputter.

"I can help," says Fat, rattling the store door. Insulin is still bustling about with her broom, still saying "not yet", and the door stays locked.

So the room does the only thing it can. It sends a message upstairs. We're low. Send something quick. The quickest thing is more sugar.

It is eleven in the morning, and the Brain reaches for the biscuit tin. The flood comes again. Then lunch. Then the three o'clock slump and the four o'clock sweet thing. Then dinner, and something on the sofa after. The room never gets a quiet hour.

Act three goes on and on

Nobody in the room is lazy or stupid. Every one of them is doing exactly what they were built to do. It is the floods that break them, one worker at a time.

The Liver goes first, and he goes silently. He grows heavy with fat.

The Mitochondria stop recovering between floods. They become inflamed. Inflammation gets into the joints, which ache in the morning. It gets into the skin. It gets into the small vessels at the back of the eyes and in the kidneys.

Then the muscles stop answering. Fat's door has not opened in months.

Night brings no rest. The last flood arrived at nine, so Insulin is still tidying at midnight and the furnaces are still smoking at two.

The Brain is the last to understand what is happening, and the first to suffer. He cannot think straight by 3pm.

Everything affects everything. The Liver's weight raises Insulin's workload. Insulin's workload keeps Fat locked in. The locked store starves the furnaces between meals and floods them at meals. The smoke makes the muscles deaf. The deafness brings more Insulin. The broken nights make it all worse tomorrow.

That is the state most of our members arrive in.

Epilogue

The room is not stuck. Every worker in it changes how they behave in response to the last few days. Give them a week without floods and the Liver begins to empty, the furnaces begin to clear, the muscles begin to hear Insulin's knock again, and Fat's door clicks open for the first time in years. The first week is the hardest, because Fat is stiff and clumsy at the handover after so long shut in.

Most of what gets called weak willpower is a body asking for fuel it's come to rely on or asking for the next dopamine hit it brings with it.

This is easily fixed. You just need to see it and understand it to change it.

About this story

Insulin's house rule is the important one. While insulin is high, the body cannot release stored fat, so hours spent with insulin up are hours spent not burning fat.

The Liver's silence is real. Fat builds up in the liver in around one adult in four, usually with no symptoms for a decade or more, and it is the organ where type 2 diabetes begins, before the pancreas follows.

The Mitochondria's smoke is inflammation. It comes from fuel arriving faster than the furnaces can use it, over months and years.

The deafness is insulin resistance. The muscles are protecting themselves from a surplus they cannot use, which means it is a response rather than a defect, and responses reverse when the cause is removed.

Working muscle takes glucose out of the blood through a route that does not need insulin at all, and muscle is where most of the sugar from a meal should end up. Ten minutes of walking after a meal lowers the rise from that meal more than a longer walk at another time of day, and strength work builds a bigger crew, which raises how much carbohydrate you can eat without a flood.

Four things move the Line: what you eat, how you sleep, how stressed you are, and whether the Muscles get used.

The Line is your glucose, read every few minutes by a sensor on your arm. A sensor cannot diagnose anything; that is what blood tests are for. What it can do is show you, within an hour, what your own breakfast did to your own room, and what a walk, an earlier dinner or a decent night's sleep did to it the next day.

There is about a teaspoon of sugar in your blood right now. Five grams, give or take, and that is the healthy amount. A bowl of cornflakes delivers around eight teaspoons in one sitting, and a large baked potato about nine.

What metabolism is

Your metabolism is how your body turns food into energy, and how it decides whether to burn that energy or store it. It answers to every meal, every night's sleep, every walk and every stressful afternoon, which is why it can change, in either direction, at any age, whatever you were told about being born with a slow one.

Good metabolism has a feel to it. Steady energy through the day. No slump after lunch. Hours without thinking about food. A clear head. If that sounds unfamiliar, the rest of this page explains what has happened, and what can be done about it.

What happens after a sugary or starchy meal

Only carbohydrates become glucose, which is the sugar your blood carries. Protein becomes amino acids and fat becomes fatty acids, and neither of them moves your glucose much. So when bread, cereal, rice, potatoes or anything sweet arrives, the teaspoon in your blood is suddenly several teaspoons, and your body has to do something with the excess fast.

Insulin is the hormone that does it. It clears the extra glucose out of your blood and packs it away, first into your liver and muscles, and once those are full, into body fat.

Insulin usually overshoots. Your glucose falls back past where it started, and for an hour or two your fat is still locked away because insulin has not come down yet. Neither fuel is easy to reach. Your brain senses energy falling and asks for the fastest fix it knows, which is sugar or starch.

Flatten the rises and the gap closes. Smaller rises need less insulin, so your fat stays reachable between meals, your energy holds and the cravings fade. The first week is usually the hardest, because a body that has run on sugar for years is slow to switch back to fat.

Burning fat and losing fat are close cousins rather than the same thing. How much you eat still matters.

Why the shape of your line matters more than any number

A glucose sensor gives you a line rather than a number, and the line is what we watch. Sharp rises and crashes do more damage to cells than a level that sits a little high and steady, so two people with the same average can have very different days. Our measure of how you are doing is built around how much your line swings, in the same way that heart rate variability says more about recovery than heart rate does.

Four things move the line

Food is the biggest, and it sets the size of the rises.

Sleep changes what food does. One short night raises your glucose the next day even if you eat exactly the same, and it raises stress hormones and hunger hormones together, which is why tired days are biscuit days.

Stress raises the line with no food involved. Stress hormones tell your liver to release glucose so you can run or fight, which was useful when threats were physical and brief, but not now.

Movement pulls glucose out of your blood before insulin has to deal with it, because working muscle takes in glucose on its own. A ten-minute walk after a meal flattens the rise from that meal. Strength work builds muscle, and more muscle raises how much carbohydrate you can eat without a spike.

Each lever on its own is small. Together they decide whether your cells spend most of the day dealing with a surplus or most of the day in balance.

What years of surplus do

Every cell has tiny engines called mitochondria that turn fuel into energy. They work best with a small, even flow matched to what the body is using. When fuel keeps flooding in and little is being spent, they cannot burn it cleanly. The excess backs up, the cell throws off damaging sparks, and it sends out alarm signals. That alarm is inflammation, and if the surplus never stops, the alarm never switches off.

Inflamed cells protect themselves by ignoring insulin. That is insulin resistance, and it is the point where the loop closes: ignored insulin means more glucose in the blood, more insulin pumped out to cope, and more inflammation from both. Fat stored deep around the organs joins in, giving off inflammatory signals of its own.

The hopeful part

Because inflammation is a response, it falls when the cause is removed, and because your metabolism is a set of jobs rather than a setting, it can be repaired.

In Dr David Unwin's NHS practice near Liverpool, more than half of patients with type 2 diabetes reached drug-free remission by changing what they ate, rising to more than three quarters of those who had been diagnosed within the previous year. Nine in ten of his patients with pre-diabetes returned to a normal blood sugar. Those people did not receive a new metabolism. They changed the one they had.

People who steady their line often notice less joint pain, clearer skin and better sleep before they notice any change in their weight.

What you'll see, and what changes

In the first two days you see your own line for the first time, and it usually contains at least one surprise. The healthy-looking breakfast that sends you up a cliff, or the dinner you assumed was the problem and turns out to be fine.

Most members are learning what their own body does with food rather than following a plan, and after a few months many find they can read the line without the sensor.

Most of what gets called weak willpower is a body asking for a glucose fuel it's become reliant on.