What is the Glycaemic Index?
The Glycaemic Index (GI) is a ranking system of carbohydrate-containing foods, based on
their immediate effect on blood sugar levels. Carbohydrate foods that breakdown and are
released quickly into the bloodstream have high GIs, whereas those that produce a more
steady and sustained rise in blood glucose are low GI foods.
Is the GI Relevant For You?
GI is especially beneficial for diabetics to use to help maintain normal blood glucose levels.
Eating low GI foods improves blood glucose control, which thus helps to prevent further
diabetic complications. Diabetics are recommended to base each meal and snack on low GI
foods. High GI foods should be limited but can be used in moderation or occasionally for
2. Cardiovascular Disease
Low GI foods can help reduce the risk of heart disease by assisting with weight loss,
improving blood glucose control, reducing blood cholesterol and improving the ratio of HDL
(good cholesterol) to LDL (bad cholesterol). Therefore, it is particularly beneficial for
everyone (especially those at risk of cardiovascular disease) to base their meals and snack
on low GI rather than high GI foods.
3. Weight Control
Incorporating a variety of low GI foods into your diet assists with satiety (‘feeling full’) and
weight reduction when used as part of a low fat diet and exercise plan. Low GI foods are
also associated with lower insulin levels, which makes fat easier to burn and less likely to be
stored. Weight loss or control is therefore more achievable if at least one low GI food is
included in every meal. However, since some low GI foods can also be high in fat and
kilojoules it is important to opt for the low fat low GI options.
4. Sports Performance
Low GI foods prolong cardiovascular endurance and prolong the onset of fatigue
when they are consumed in the pre-exercise meal (2 to 4 hours prior to exercise).
Athletes should therefore choose low GI options for their pre-exercise meal or snack.
Conversely, high GI foods significantly improve the speed at which our bodies replenish
glycogen (energy) stores in your muscles after exercise. The faster these glycogen stores
are replenished, the more completely your body recovers after exercise and the better you
will be able to perform in subsequent training sessions and games/events. Thus, elite
athletes in their key competitions or training sessions will experience slightly quicker
recovery if they include high GI foods in their post-exercise meal, ideally immediately after
the session. However, for most sports participants and especially juniors, it is best to opt for
the healthier low GI carbohydrates.