The GI concept was first introduced as a tool for diabetic people to help regulate insulin. Today the World Health Organization (WHO) recommends the consumption of low glycemic index foods to prevent not only diabetes but also obesity and cardiovascular disease.
WHO recommendations
- Simple carbohydrates, such as glucose or sucrose, are characterized by a high GI value: rapidly digested, they cause a rapid and significant rise in blood glucose. This is stored in the form of fat (lipogenesis) when not utilized by the body straight away, thus inducing weight gain.
In response to this sudden energy supply, the body releases large amounts of insulin to help maintain glucose concentration within a narrow range. Sharply increased insulin secretion causes an abrupt fall in blood glucose below the normal range. This 'peak and fall' fluctuation leads to hypoglycemia two hours after ingestion, resulting in a rapidly increasing sensation of hunger.
- Repeated intake of high GI sugars may lead not only to overfeeding but also to ongoing hyperglycemia, which induces insulin resistance. The latter phenomenon is closely linked with the pre-diabetes status (metabolic syndrome).
Continuously exposed to elevated levels of insulin, the body becomes less receptive and needs to secrete even more insulin to maintain the appropriate blood sugar level, leading ultimately to increased risk of diabetes.