GI stands for the “Glycaemic Index”, and it is a ranking from 1 to 100 that measures the effect of a food on your blood glucose levels over the two hours after the food is eaten. A low GI food is 55 or less, a medium GI food is 56-69, and a high GI food is 70 or more. A higher GI food will see the blood glucose level rise and fall sharply, while a lower GI food will see a slower, steadier rise in blood glucose levels.
Very high glucose levels after a meal is damaging to the arteries and other blood vessels and they cause an excess of insulin in the body. Eating low GI foods means that you can avoid these dramatic rises and falls in blood glucose levels, therefore giving you a steadier stream of energy. You will reduce your cravings for sugar and other sweet foods. Your risk of heart disease and other chronic diseases is also reduced. Low GI foods are excellent for weight loss. Not only do they fill you up and keep you feeling satisfied for longer, thus helping you to reduce your daily kilojoule intake, they also reduce insulin levels and help you to burn more body fat and less muscle, so that your metabolic rate is higher.