An indication of how eating a particular food will affect the concentration of glucose in the blood. GI is determined relative to the effects of a standard test meal of (usually) 50 g of glucose in a fasting individual, which is given the value 100. Foods with a high GI (typically >85), such as white bread, white rice, and potatoes, cause blood glucose to rise rapidly following ingestion, whereas the increase is lower and more prolonged in foods with a low GI (<60), such as apples, beans, and yogurt. The GI of a food is governed by various factors, such as the type of carbohydrate, the concentration and nature of the fibre, the proportions of protein and fat, and the methods of cooking or processing. Lower GI foods are recommended for endurance sports and to optimize control of blood glucose for diabetics.