Rice provides more than one fifth of the world's consumed calories and is a hugely important crop in China. In these carbohydrate-conscious times it has acquired a bad reputation, but it is an invaluable source of nutrition as the Chinese know.

The Glycemic Index (GI) ranks the rate at which carbohydrates are broken down and absorbed as sugar into the blood stream compared to pure glucose. The lower the GI, the better for health as fluctuations in blood sugar and insulin levels are minimized. A low GI is less than 55, medium, 56-69 and high more than 70. The GI for rice varies with grain length and constituent starch type.

The Oryza sativia rice species predominates in Asia and different varieties are classified according to grain length and color. In China, medium to long grain white rice is generally served as the staple food with meals. On formal occasions it is not served at all as it is considered cheap, filling food.

White rice is by no means a bad food. Usually it is enriched to replace nutrients lost in milling and provides notable amounts of B vitamins and the minerals phosphorous and magnesium. It also contains a good supply of some of the amino acids required to make protein in the body.

Long grain rice is preferable because it tends to have higher amylose content (type of starch) and so when cooked, the grains remain distinct and do not become sticky. Regular long grain Chinese rice has a varying GI between 60-80. The aromatic Basmati rice, consumed predominately in South Asian countries, is an excellent choice with a GI of around 54. The Australians, who are pioneers in the GI research field, have developed a strain of rice called Doongara or Clever rice with an impressively low GI of 46.

Shorter, stickier grain varieties have a higher GI (greater than 90) and are therefore less beneficial. In China, congee or rice porridge is made with glutinous, short grain rice and flavored with sweet or savory ingredients. Different types of congee are believed to have different medicinal benefits. Zongzi are steamed glutinous rice parcels filled with the likes of bean paste, pork or mushrooms, enveloped in a bamboo leaf.

Brown rice retains most of its husk and so is naturally superior in vitamin and mineral content. Most significantly it is fiber-rich, which moderates the GI (50-60) and is great for the bowels!

Be wary of left over, un-refrigerated rice. Most cases of the runs following a Chinese take-away are erroneously blamed on bad chicken or prawns when Bacillus cereus, a rice bacterium is the real culprit.

Rice is a nutritious, low-fat carbohydrate option (provided it is not fried!). Restrict yourself to one bowl and choose brown or basmati rice when cooking at home. Add beans and pulses to lower the GI of short grain rice.

The nutrition-related column is written by Nina Lenton, a qualified dietitian living in Beijing. Contact her at nina_lenton@hotmail.com.

(China Daily 04/04/2007 page14)