The people of Hong Kong consume up to 330,000 tonnes of rice every year. We are loyal to that fragrant bowl of jasmine rice. It fills us up and gets us moving.
'In terms of how it gives us energy, not all rice is created equal,' says Flavia U, a dietitian at the Hong Kong Sanatorium and Hospital. 'Most of us know that whole- grain and brown rice varieties are 'better' for us; because the husk balances the carbohydrates with vitamins, minerals and fibre.'
But there's more to evaluating the healthiness of rice varieties, namely, by how quickly each is digested by the body. When carbohydrates are broken down into glucose and sent into the blood stream, the process cues the release of insulin by the pancreas to manage blood-sugar levels.
Simple sugars and carbohydrates that can be digested quickly flood the bloodstream with glucose, causing a spike; then the pancreas reacts with large amounts of insulin. Once the glucose is absorbed, the excess insulin and low blood-sugar can cause weakness and hunger. So unless you are 'carb-loading' for the 100-metre dash, the ideal carbohydrate is complex (slower to break down). Your blood sugar and insulin levels rise slowly, giving you more consistent energy levels.
Thanks to a nifty nutritional reference called the glycaemic index (GI), we can compare the rates of glucose conversion of different food items, including rice. The GI value is derived from measuring the blood-sugar levels of 10 to 20 individuals, before and after the ingestion of 50 grams of a foodstuff. Blood is tested every 15 minutes for two hours, and the average blood-glucose curve is crunched into a single number. Pure glucose, the control food, has a GI of 100. Foods that score 70 to 99 are in the high GI category, 56 to 69 is the medium range, and anything below 55 is considered low GI and the most healthy.
'The GI is a helpful reference for dietitians,' U says.
