Refined carbohydrates and added sugar:
Refined carbohydrates are carbohydrates that have been processed to remove most of their fibre, vitamins, and minerals.
White bread, white rice, sugary cereals, biscuits, cakes, and sugary drinks are all examples.
These foods cause rapid, repeated blood sugar spikes.
Each spike triggers a surge of insulin.
Repeated surges over months and years drive insulin resistance.
Think of it like repeatedly flooding an engine.
The mechanism is not designed for that level of repeated stress.
Over time it breaks down.
Physical inactivity:
Muscle is one of the primary places where blood sugar is absorbed and used.
When muscles contract during movement, they absorb glucose, which is blood sugar, directly from the bloodstream without even needing insulin to open the door.
Think of muscle as a second entrance into the cell.
One that opens without a key.
Physical inactivity keeps this second entrance closed.
Blood sugar stays higher for longer.
Insulin has to manage all of it alone.
The system is under more stress than necessary.
Poor sleep:
A single night of poor sleep measurably increases insulin resistance the following day.
Sleep is metabolic medicine.
Skipping it is metabolic damage.
Chronic stress:
Cortisol, which is the body’s primary stress hormone, directly raises blood sugar.
Think of cortisol as an emergency override switch.
When the brain senses danger, it tells the liver to release glucose, which is stored sugar, into the bloodstream to prepare the body for action.
This is useful in a genuine emergency.
But when cortisol is chronically elevated through ongoing stress, the body exists in a permanent state of elevated blood sugar.
Insulin is constantly being called upon.
The system is always under load.
Ultra-processed food:
Ultra-processed food is food manufactured with artificial ingredients, emulsifiers, preservatives, and large amounts of added sugar and salt.
It is designed to be eaten quickly and in large amounts.
It is typically very low in fibre, which is the part of plant food that slows down how quickly glucose enters the bloodstream.
Ultra-processed food drives blood sugar instability, promotes the storage of fat around the organs, and disrupts the gut microbiome, which is the community of microorganisms living in the digestive system, in ways that worsen insulin resistance.