If Nestlé breakfast cereals have a high GI, doesn’t that make them unhealthy?
No. It’s not accurate to define the healthiness of a food by considering one component in isolation – whether it’s GI, sugar or fibre content. There’s no universal agreement among experts on the effect on GI on health. GI doesn’t tell you how nutritious a food is. It indicates the availability of the carbohydrate to digestion. Oats, for example, are medium GI, but they’re 100% whole grain, high in fibre, a source of protein and have with no added sodium. Although our breakfast cereals have medium to high GIs, they’re usually consumed with milk (which has a low GI), which lowers the overall glycaemic load (GL) of the meal. The GI may be useful for people with diabetes to help them manage their blood glucose levels – though the evidence on this isn’t consistent either. The European Food Safely Authority (EFSA) has yet to approve any health claims linked to GI. And the other evidence linking GI, GL and health is largely inconclusive.