Some low GI foods, appreciate wholegrain foods, fruit, vegetables, beans and lentils, are foods we should always eat as a part of a healthy, balanced diet.
However, "using the glycaemic index to come to a decision whether or not foods or combos of foods are healthy are often misleading", says the NHS.
The health body explains: "Foods with a high GI aren't essentially unhealthy and not all foods with an occasional GI are healthy.
"For example, watermelon and parsnips are high GI foods, whereas cake incorporates a lower GI value."