Do Rice Crackers Spike Your Blood Sugar? A Singapore Guide to the Glycaemic Index

August 3, 2026

Do Rice Crackers Spike Your Blood Sugar? A Singapore Guide to the Glycaemic Index

If you have ever swapped a packet of chips for rice crackers because they felt like the lighter choice, this one may sting a little. On the Health Promotion Board's own glycaemic index table, crackers and rice cakes sit in the high column — the same band as white rice and cornflakes.

That is not the end of the story. The glycaemic index is one of the most misread numbers in nutrition, and knowing what it does and does not measure changes how you shop.

What the glycaemic index actually measures

The glycaemic index (GI) ranks carbohydrate-containing foods from 1 to 100 based on how quickly and how much they raise blood glucose after eating, according to HealthHub, HPB's consumer health portal. Foods causing the most rapid rise get higher values; foods causing a gradual rise get lower ones.

The cut-offs are standardised internationally under ISO 26642:2010 and are used directly in HPB's own product guidelines: low is 55 or below, medium is 56 to 69, and high is 70 to 100.

Where crackers actually sit

HealthHub groups common foods into three bands. In the high band (70–100), under “Snacks”, you will find pretzel, rice cake, cracker, dried dates. White rice, white bread and cornflakes are in the same band.

Said plainly: as a category, plain rice crackers are not a low-GI food. Puffed, highly processed starches gelatinise easily and digest fast, behaving much like the refined staples they are made from.

Locally relevant numbers are also thinner than you would hope. A 2021 compendium led by researchers at Singapore's Clinical Nutrition Research Centre exists precisely because the overwhelming majority of published GI values come from Europe, Australia and North America. If a product has not been tested, any GI figure quoted for it is an estimate, not a measurement.

But low GI does not mean healthy

Here is the part that trips people up. Look again at HealthHub's low GI column and you will find ice-cream and snickers bar listed there. Fat and protein slow gastric emptying, which flattens the glucose curve — even in a food nobody would call a health choice.

GI ranks one narrow property: the speed of the glucose response. It says nothing about sodium, saturated fat, added sugar, fibre or calories. It is one line on the scorecard, never the whole scorecard.

What genuinely blunts the spike

This is where the research gets practical. A study by Tan and colleagues at the Clinical Nutrition Research Centre, published in the British Journal of Nutrition, tested ten commercially available breakfast and snack foods in nineteen healthy Singaporean men. Asian rice-based items came out medium to high — rice idli at 85, rice dosa at 76 — while the wholegrain Western items all came out low, between 44 and 55.

The useful finding was the pattern behind those numbers. The GI of the test foods correlated negatively with protein, fat and dietary fibre content — all three, all statistically significant. In plain terms: the more protein and fibre sitting alongside the starch, the gentler the glucose response tended to be.

Two things follow from that:

Composition matters more than the base ingredient. A cracker built on refined starch alone behaves differently from one carrying meaningful protein and fibre.
What you eat it with counts. Crackers with peanut butter, hummus, cheese or eggs is a different glucose event from crackers alone.

Portion size is doing more work than you think

GI is measured in the lab on a portion delivering a fixed amount of available carbohydrate — typically 50 g, far more than most people eat in one snack sitting. A high-GI food in a small portion can have less real-world impact than a moderate-GI food eaten by the handful in front of the TV.

Can a snack legally claim “Low Glycaemic Index” in Singapore?

Yes — but the bar is higher than most shoppers realise. Under the HPB Healthier Choice Symbol Nutrient Guidelines, a Low Glycaemic Index tagline is an optional secondary claim, and the product must:

First meet all the Healthier Choice Symbol nutrient criteria for its category;
Have a tested GI value below 55, using in-vivo testing per ISO 26642:2010; and
Contain at least 7.5 g of carbohydrate per serving (or have carbohydrate as at least half its macronutrients) to even be eligible for testing.

Savoury biscuits and crackers are one of the categories where that tagline is available — but only after clearing the category thresholds, which include under 420 mg sodium per 100 g, under 10 g saturated fat per 100 g, and at least 30% wholegrains. That is a meaningful hurdle, which is why you see the claim so rarely on a snack shelf.

What to actually do in the supermarket aisle

Ignore unverified GI numbers on marketing copy. If it were tested and below 55 and the product qualified, it would carry the HCS tagline.
Use protein and fibre per serving as your practical proxy — they are on the nutrition information panel, and the research says they track with a gentler response.
Check whether wholegrain is the first ingredient rather than a refined starch.
Decant into a bowl. Portion beats GI arithmetic almost every time.
If you are managing diabetes or prediabetes, speak to your doctor or a dietitian — GI is a tool, not a treatment plan.

Where HexaCrunch fits

We make baked brown rice crackers with cricket protein, and we are not going to claim they are a low-GI food — we have not put them through ISO 26642 testing, and we would rather say nothing than say something untested. What we can say is that the protein and fibre from cricket flour are exactly the components the Singapore research associates with a gentler glucose response, and that they are baked rather than fried. If you would like to taste-test all three flavours before committing to a favourite, the Try-All 3-Pack is the easiest place to start.

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