The glucose in your blood comes from the carbohydrates in your food. Carbohydrates include sugar and starchy foods such as bread, pasta and rice.
When you eat, the carbohydrates pass from your stomach into your small intestines.
The carbohydrates are then broken down into glucose. Your body converts some of
the glucose into a chemical called “glycogen”, which it stores in your liver and muscles.
The remaining glucose will travel through the bloodstream to fuel your body’s cells
and organs. This is the glucose you are measuring when you self-test your blood
glucose level. Your brain and the cells in your body need the energy from glucose
to function, so it is important that your blood glucose level is within a healthy
range.
During a meal and for the following two to three hours, the carbohydrates in your
food will be used to fuel your cells and body. After this, the carbohydrate part
of the meal is used up and your blood glucose level starts to drop. Your liver then
converts its
glycogen stores back into glucose and sends it into your bloodstream. If
you haven’t eaten for a long time and your glycogen stores have run out, your body
converts its fat and protein stores into glucose. This process is called “gluconeogenesis”.
Therefore there are three ways that glucose gets into your blood:
1. Your bloodstream’s main source of glucose is from the carbohydrates that you
eat.
2. Your body converts some of the glucose from the carbohydrates you eat into a
chemical called glycogen, which it stores in your liver. If your blood glucose level
falls too low, your liver will convert the glycogen back into glucose and send it
into your bloodstream to boost your blood glucose level.
3. When there isn’t a supply of carbohydrate from your diet and your glycogen stores
have run out, your blood glucose level drops. Your body will then convert its fat
and protein stores into glucose using a process called “gluconeogenesis”.