Low-GI Rice: How Low Is “Low” — and What Exactly Are You Paying For?

Walk through an Indian supermarket today and rice seems to have acquired a medical degree.

There is low-GI rice.
Diabetic rice.
Sugar-control rice.
Sometimes even “sugar-free rice.”

That last one is particularly clever.

Because ordinary rice does not contain spoonfuls of table sugar either.

The real story of low-GI rice is much more interesting — and much less magical.

It started with genuine agricultural science

At the Rice Research Centre of Professor Jayashankar Telangana State Agricultural University in Rajendranagar, Hyderabad, breeders began developing a new rice variety in 2006.

They crossed two established varieties, MTU 1010 and JGL 3855, using conventional pedigree breeding. The resulting variety was RNR-15048, later named Telangana Sona.

So this is not an ancient native rice variety suddenly rediscovered, and it is also misleading to think of the rice sold today as an F1 “hybrid rice”. It is a stable, conventionally bred variety derived from a cross.

The original goals were largely agricultural: a short-duration, high-yielding, fine-grained rice with good cooking quality and resistance to disease. Telangana Sona was released in 2015 and officially notified in 2016.

Then researchers discovered something commercially much more exciting.

Its glycaemic index was relatively low.

In a published study involving 54 healthy adults, RNR-15048 had a GI of:

51.72 ± 3.39

compared with 73.4 ± 7.79 for the comparator white rice.

And a new retail category was born:

“Diabetic rice.”

But 51.72 is only just inside the low-GI category

GI is usually classified as:

Low: 55 or below
Medium: 56–69
High: 70 or above

So yes — 51.72 qualifies as low GI.

But look where it sits.

Only a few points below the boundary.

And the reported result was 51.72 ± 3.39, not simply an immutable number of 51.72.

That ±3.39 should not be interpreted as proving that different commercial packets range between particular GI values — it describes uncertainty/variability around the study estimate. But it is a useful reminder that GI is a biological measurement, not an engraving on a rice grain.

There is no metabolic cliff between GI 54 and GI 56.

Yet commercially, one can carry LOW GI prominently on the packet while the other cannot.

That distinction can look much bigger in the supermarket than it really is physiologically.

And then comes the awkward number nobody puts on the front of the packet: GL

The original RNR-15048 experiment gave participants enough rice to provide 50 g of available carbohydrate — around 226 g of cooked rice.

Glycaemic load takes into account both GI and the amount of carbohydrate eaten.

Using the study’s own numbers:

GL = 51.72 × 50 ÷ 100 = 25.9

A glycaemic load of:

10 or less = low
11–19 = medium
20 or more = high

So the original experimental meal was simultaneously:

LOW GI

and

HIGH GL

That is not a contradiction.

GI asks roughly how rapidly a carbohydrate-containing food raises glucose relative to a reference.

GL asks how much glycaemic impact you get after considering the amount of carbohydrate you actually ate.

And this matters enormously with rice.

A bowl of low-GI rice is still predominantly starch.

Low GI does not mean low carbohydrate.

Low GI does not mean low glycaemic load.

And it certainly does not mean no glucose spike.

Then we met the hawk-eyed customers

Most customers will never discover this distinction.

They see LOW GI, DIABETIC FRIENDLY or SUGAR CONTROL, eat their rice and reasonably assume the product is doing what those words imply.

Perhaps 99% will never measure their glucose afterwards.

One of our customers did.

They wore a continuous glucose monitor and noticed that an unnamed brand of commercially sold low-GI rice produced a much larger glucose excursion than their usual basmati rice.

That is one individual’s observation — not a clinical trial.

But it raised an obvious question:

What exactly was inside that packet?

Later, we spoke to a trader involved in the low-GI rice business who told us that adulteration was an acknowledged problem within the supply chain.

He described one commercial batch marketed as low-GI rice which, when reportedly sent for testing, returned a GI of approximately 64.

Again, that anecdote does not prove that every low-GI rice is adulterated.

But it raises a very legitimate consumer question:

If the published science was performed on genetically defined RNR-15048, how do you know every grain in a commercial bag is actually RNR-15048?

Premium rice attracts a premium price.

Mixing it with cheaper conventional varieties — whether deliberately or somewhere through a complicated supply chain — changes what eventually reaches the customer’s plate.

The rice grains themselves do not come with identity cards.

Then there is another question: what exactly is a ₹4,000 “GI test”?

A trader also mentioned GI testing costing only a few thousand rupees.

That should immediately prompt another question:

What kind of test?

A proper human GI determination is not simply a laboratory placing rice into a machine and printing a number.

Standard human GI methodology involves volunteers arriving fasted, consuming a portion containing a defined quantity of available carbohydrate, repeated reference-glucose measurements and multiple blood glucose measurements over approximately two hours.

There are also in-vitro starch digestion tests that can produce an estimated GI.

Those may be useful as laboratory screening tools.

But an estimated GI is not the same thing as a properly performed human GI study.

So before accepting “GI tested” on a packet, consumers should be asking:

Where was it tested?

Was it tested in humans?

What methodology was used?

Was the commercial product tested — or is the manufacturer quoting research performed years ago on the original rice variety?

And perhaps most importantly:

Was this particular batch ever tested at all?

What about the nutrition?

RNR-15048 is an interesting rice variety, but it has not suddenly become a protein-rich, fibre-rich superfood.

It is still fundamentally polished rice.

Its principal advantage is its starch characteristics and resulting lower measured GI — not a dramatic transformation in its protein, fibre or micronutrient content.

So paying a substantial premium makes sense only if the product genuinely contains the claimed variety and the lower glycaemic response matters to you.

And then we reach “sugar-free rice”

This may be the most misleading phrase of all.

Rice contains very little simple sugar.

But it contains plenty of starch.

Your digestive system breaks that starch down into glucose.

So a product can be technically very low in “sugars” on a nutrition label and still produce a substantial rise in blood glucose.

The consumer with diabetes does not read SUGAR FREE and think:

“Excellent — this food contains little mono- and disaccharide.”

They are much more likely to think:

“This won’t increase my blood sugar.”

Those are completely different statements.

And FSSAI is becoming increasingly interested in misleading claims

This is unlikely to remain merely an academic debate.

FSSAI already prohibits misleading food advertisements and claims, and its Advertising and Claims Regulations place restrictions on claims implying that foods can prevent, treat or cure diseases.

It has previously taken action against food businesses over misleading health and product claims, including claims involving staple foods.

In 2025, FSSAI also strengthened mechanisms allowing consumers to report misleading claims on packaged foods through its app and portal, while separately warning food businesses against other potentially misleading front-of-pack terminology such as sweeping “100%” claims.

That makes increasingly aggressive language around products such as rice — “reverses diabetes”, “controls diabetes”, “diabetic rice”, “sugar-free” — an area manufacturers would be wise to watch carefully.

There is an enormous difference between saying:

“This particular rice variety has demonstrated a lower GI in a human study.”

and suggesting:

“Eat this rice and reverse your diabetes.”

One is a scientific statement.

The other is a medical promise.

So what rice should you eat?

There is no single GI for “rice”.

The glycaemic response varies with the cultivar, amylose content, processing, cooking time, portion size and even what happens to the rice after cooking.

Studies of commercially available rice have found GI values ranging from 37 to 92.

Basmati can sometimes perform surprisingly well. One multicentre Indian study, for example, found a thermally treated basmati rice to have a GI below 55.

Cooling rice is also interesting. When cooked rice is refrigerated, some of its starch retrogrades and becomes resistant starch. In one study of people with type 1 diabetes, rice cooled for 24 hours and reheated produced a significantly smaller post-meal glucose rise than freshly cooked rice.

That does not turn yesterday’s rice into a diabetes medicine either.

It simply illustrates how much the glucose response depends on more than the name of the grain.

Rice: GI versus GL

The bottom line

RNR-15048 is a genuine and interesting piece of Indian agricultural science.

The problem begins when “GI 51.72 ± 3.39” becomes “diabetic rice.”

And then “diabetic rice” becomes:

“sugar free”

or

“controls diabetes”

or, worse,

“reverses diabetes.”

A GI of 51.72 is a scientific measurement.

“Diabetic rice” is a marketing interpretation of that measurement.

And perhaps the most revealing fact is the one you are unlikely to see in large letters on the packet:

The original RNR-15048 study meal was low GI — but high GL.

So if you have diabetes and choose to eat rice, by all means consider a genuinely lower-GI variety.

But don’t surrender your common sense at the supermarket shelf.

Check the portion.

Check the source.

Check the testing.

And occasionally, if you have a glucometer or CGM, check what the rice actually does to you.

Because your blood sugar cannot read the marketing on the packet.