Low GI rice is any rice variety that scores 55 or below on the glycemic index, a scale that ranks how quickly foods raise blood sugar compared to pure glucose (scored at 100). Most rice actually falls in the medium to high GI range, with tested varieties scoring between 64 and 93. Only certain types of rice, specifically those with a high proportion of a particular type of starch called amylose, consistently qualify as low GI.
Why Most Rice Has a High GI
Rice starch is made up of two components: amylose and amylopectin. Amylopectin has a branched structure that digestive enzymes can break apart quickly, flooding your bloodstream with glucose in a short window. Amylose, by contrast, has a straight, linear structure that resists those same enzymes, so it breaks down more slowly and releases glucose gradually.
Standard white rice, including many popular jasmine and short-grain varieties, tends to be high in amylopectin and low in amylose. That’s why it digests fast and spikes blood sugar. Sticky (glutinous) rice is the most extreme example, with almost no amylose at all, giving it some of the highest GI scores of any rice type. A systematic review in The British Journal of Nutrition found that many varieties of rice, whether white, brown, or parboiled, should be classified as high GI foods. The assumption that brown rice is automatically low GI is a common misunderstanding.
The Amylose Threshold That Matters
Rice varieties with more than 25% amylose content are classified as “high amylose” and tend to produce a noticeably smaller blood sugar spike after eating. But the research suggests a more specific cutoff: when amylose content exceeds about 27%, the GI consistently drops below 70 (the boundary between high and medium GI). Rice with 24.5% amylose, for instance, still tested at a GI of 73 in one study, while varieties above 27% reliably came in lower.
As amylose content climbs, the rate at which your body breaks down the starch slows further. The starch essentially behaves more like resistant starch, a type that passes through the small intestine partially undigested, similar to fiber. This is why high-amylose rice varieties are the only ones consistently useful in a low GI diet.
Rice Varieties With Lower GI Scores
Not all rice sold as “low GI” performs the same way in testing. Here are the varieties with the most reliable evidence behind them:
Doongara rice is an Australian-grown, high-amylose variety and one of the most consistently tested low GI options. White Doongara scored a GI of 64 when boiled for 14 minutes, and brown Doongara came in at 66. In another trial comparing responses across different populations, Doongara scored as low as 55. It has a firm, slightly chewy texture that holds its shape well.
Basmati rice is more variable. Some tests have recorded basmati at a GI of 57, while others measured it as high as 94 for white basmati and 116 for brown basmati. The wide range likely reflects differences in the specific basmati cultivar, growing region, and how long it was cooked. If you’re choosing basmati for blood sugar reasons, look for brands that publish tested GI values on their packaging rather than assuming all basmati is low GI.
Other high-amylose varieties are now being bred and marketed specifically as low GI rice in countries like Australia, India, and Sri Lanka. These are sometimes labeled “low GI” on the package, ideally backed by testing under the international standard (ISO 26642:2010), which measures actual blood sugar responses in human volunteers rather than estimating GI from starch chemistry alone.
How Cooking and Cooling Change the GI
The way you prepare rice matters almost as much as the variety you choose. Overcooking rice breaks down starch granules more completely, making them easier to digest and raising the GI. Shorter cooking times preserve more of the starch structure and keep the GI lower.
Cooling cooked rice after preparation is one of the simplest ways to reduce its glycemic impact. When rice cools, some of the starch undergoes a process called retrogradation, rearranging into a tighter structure that resists digestion. In one clinical study, freshly cooked white rice contained 0.64 grams of resistant starch per 100 grams. Rice cooled for 10 hours at room temperature doubled that to 1.30 grams, and rice refrigerated for 24 hours then reheated reached 1.65 grams. The refrigerated-and-reheated rice produced a significantly lower blood sugar response in participants compared to freshly cooked rice. This means leftover rice, rice salads, and meal-prepped rice dishes are all naturally lower GI than rice served straight from the pot.
What About Parboiled Rice?
Parboiled (converted) rice goes through a steam-and-dry process before the husk is removed. This hydrothermal treatment causes the starch to gelatinize and then re-form into a more compact structure as it cools, increasing resistant starch content and reducing how quickly enzymes can break it down. The process also creates amylose-lipid complexes that further slow digestion.
Parboiled rice generally has a lower GI than the same variety cooked from raw, though results vary. Some parboiled products still test in the high GI range, so parboiling alone isn’t a guarantee. The combination of a high-amylose variety that has been parboiled tends to produce the best results for blood sugar control.
Choosing Low GI Rice in Practice
If you’re selecting rice specifically for its glycemic impact, prioritize variety over color. Brown rice is often marketed as the healthier choice, but its GI can be just as high as white rice depending on the cultivar. The amylose content of the grain matters far more than whether the bran layer is intact.
- Look for labeled GI values. Some brands now test and certify their rice under ISO standards. A GI number on the package is more reliable than vague “low GI” claims.
- Choose high-amylose varieties. Doongara, certain basmati cultivars, and specifically bred low GI lines are your best options. These rices tend to cook up firmer and less sticky.
- Don’t overcook. Cook rice until just tender. The longer it boils, the more the starch structure breaks down.
- Cool before eating when possible. Refrigerating cooked rice overnight and reheating it the next day meaningfully increases resistant starch and lowers the glycemic response.
- Pair with protein, fat, or vegetables. Eating rice as part of a mixed meal slows digestion overall, blunting the blood sugar spike regardless of the variety.
Portion size also plays a role. The glycemic index measures the response to a fixed amount of carbohydrate (usually 50 grams), but in real life, eating a smaller serving of even a high GI rice will produce a smaller blood sugar rise than a large bowl of low GI rice. For people managing diabetes or prediabetes, combining a genuinely low GI variety with reasonable portions and the cooling trick offers the most practical benefit.