Insulin and KetosisUpdated a day ago
To understand how keto works, you need to understand insulin. This is one of the most important hormones involved in ketosis and fat loss. We will keep this simple and practical.
What insulin does in the body
Insulin’s main job is to manage blood sugar.
When you eat carbohydrates such as bread, fruit, cereal, rice, or sugar, they break down into glucose. That glucose enters your bloodstream.
Insulin acts like a key.
It opens the door to your cells so glucose can move from the blood into the cells and be used for energy.
That is insulin doing its job correctly.
What happens when blood sugar stays high
Problems start when blood sugar is high most of the time.
If you eat carbohydrates at most meals and snacks:
Blood sugar stays elevated
Insulin is released repeatedly
Insulin and glucose remain in the bloodstream longer than they should
This leads to inflammation in the body and stresses the system.
How insulin resistance develops, with an example
Your cells have insulin receptors. Think of them like locks on a door.
At first:
A small amount of insulin opens the door easily
Glucose moves into the cell without issue
Over time, with constant insulin exposure:
The locks become worn and less responsive
More insulin is needed to open the same door
This is called insulin resistance.
Practical example:
It is like knocking on a door over and over all day. Eventually, the person inside stops responding unless you knock louder and louder.
As insulin resistance increases:
Insulin builds up in the blood
Blood sugar remains higher for longer
Inflammation increases
Energy delivery to cells becomes less efficient
This contributes to fatigue, weight gain, and difficulty losing fat.
Why this matters for keto
High insulin blocks fat burning.
As long as insulin is high:
The body prioritises using sugar
Fat stays locked in storage
Ketosis cannot occur
This is why simply eating more fat does not cause ketosis if carbohydrates remain high.
What keto changes
Keto reduces carbohydrate and sugar intake. This lowers the amount of glucose entering the bloodstream.
As a result:
Blood sugar levels drop
Insulin levels fall
Insulin receptors get a break
This break allows insulin receptors to recover and become sensitive again.
What improved insulin sensitivity means
When insulin sensitivity improves:
Less insulin is needed to manage blood sugar
Blood sugar stays more stable
Inflammation decreases
Cells receive energy more efficiently
This also means that when you do eat carbohydrates in the future, your body can handle them better without large spikes in insulin or inflammation.
Simple takeaway for beginners
Insulin moves sugar from blood into cells
Constant sugar intake keeps insulin high
High insulin leads to insulin resistance and inflammation
Keto lowers sugar intake, reducing insulin
Lower insulin allows fat burning and ketosis
Bottom line
Ketosis works because it lowers insulin.
Lower insulin allows the body to heal its insulin response, reduce inflammation, and access stored fat for fuel.