Carbs that are broken down quickly by your body and cause a rapid increase in blood glucose have a high GI rating.
High GI foods include sugar and sugary foods, sugary soft drinks and white bread.
Low or medium GI foods are broken down more slowly and cause a gradual rise in blood sugar levels over time.
They include some fruit and vegetables, pulses and wholegrain foods, such as porridge oats.
“Some low GI foods, such as wholegrain foods, fruit, vegetables, beans and lentils, are foods we should eat as part of a healthy, balanced diet,” notes the NHS.