Carbohydrates are an essential part of our diet, but not all of the foods that contain carbohydrates are equal. Carbohydrate containing foods can be rated on a scale depending on their effect on the blood sugars called glycemic index. In high carbohydrate containing foods, foods high in GI are usually starchier, sugary and refined while a low GI food is more fibrous.
Low glycemic index (GI of 55 or less): Most fruits and vegetables, beans minimally processed grains, low-fat dairy foods, and nuts.
Moderate glycemic index (GI 56 to 69): White and sweet potatoes, corn, couscous, breakfast cereals such as Cream of Wheat and Mini Wheat’s.
High glycemic index (GI of 70 or higher): White bread, rice cakes, most crackers, bagels, cakes, doughnuts, croissants, waffles, most packaged breakfast cereals.
Glycemic Index can be lowered by combining the high GI food with fibre, protein or fat, these slow down the release of sugar into the blood stream. For example, white rice has a high GI however if combined with dal or vegetables the overall glycemic index of rice is reduced. Other factors that affect GI include size, texture, ripeness and cooking. For example unripe banana has a GI of 30 while ripe banana had a GI of 50.
GI and weight loss: A low GI diet is an effective way and helps lose weight by controlling sugars and appetite.
GI and exercise: Eating food low in GI two hours before endurance events improves exercise capacity. On the other hand high GI foods are recommended during first 24 hours of recovery to rapidly replenish muscle fuel stores.
However it is not always necessary to choose all low GI foods. There is a room in a healthy diet for moderate to high GI foods, and many of these can provide important sources of nutrients. Population at risk for Diabetes are always highly advised to follow a low GI diet, by a rule of thumb.