What is GI?

GI stands for (Glycaemic Index).  This is a medical term for measuring the speed at which various foods in our digestive system break down into glucose – and this is the body’s source of energy.  Glucose is given the number 100 (in the same way boiling water is ‘given’ the number 100 when calculating temperature in celcius).  All other foods are calculated against that number.

So for example, the cereal cornflakes, which digest quickly, has a Glycemix Index of 77, but porridge is calculated at 42 because it digests more slowely, and yoghurt is even lower at 14.  These numbers tend to be a measure of how much carbohydrates (or carbs) a type of food has.  To learn more about how carbohydrates work click here

People on the GI diet will tend to eat meals that consist of foods with low GI and will be encouraged to avoid high GI foods. However mixing low GI foods with high GI foods lowers the GI of the whole meal, this can make it much less restrictive than other diets. Low GI does not always mean low fat, so it is advisable to watch the fat content in your meals. You can find the GI content of different foods here

Eating lots of low GI foods has two advantages:

The rush of energy given by high GI foods does not last and is soon followed by an energy lull so you get hungry and want to eat more.  By eating GI low food you will feel fuller for longer.

Eating low GI foods deprives your body of a ready source of energy, which means it will have to burn fat.