Glycemic index is a value showing how quickly consumed food increases blood sugar levels. Lower glycemic index means that the food is causing slow and steady increase of these levels and is recommended for people with diabetes. Foods with low glycemic index include green vegetables, raw carrots, chickpeas and lentils. However, foods with high glycemic index are beneficial after exercising and extensive sports when they can help recover body and energy levels quickly. Higher glycemic index includes foods like pasta, potatoes, bread, corn, rice and even watermelon and pineapple.