HARI RAYA without ketupat is like rendang without coconut milk: technically possible, but nobody is doing it.
Malaysians consume these tightly woven rice cakes by the plateful every festive season, often alongside rich gravies and curries that make it very easy to lose count of how many you have eaten.
But here is the question nobody thinks to ask at the Raya table: is ketupat actually better for your blood sugar than a regular plate of white rice?
Verdict:
TRUE
Ketupat appears to have a gentler effect on blood sugar levels than plain white rice, and the science behind it is more interesting than you might expect, though that is not a green light to go back for a fifth piece.
This matters more in Malaysia than almost anywhere else. According to the National Health and Morbidity Survey 2023, 15.6% of Malaysian adults, or nearly one in six, are living with diabetes, and the country has one of the highest diabetes rates in the Asia-Pacific region, with approximately one in five adults affected, according to data cited by Monash University Malaysia researchers.
White rice on its own already has a high glycaemic index (GI), the scale that measures how quickly a food raises blood sugar levels, generally falling between 70 and 80 for short-grain varieties and 56 to 69 for long-grain types, according to Harvard Medical School.
Ketupat, however, is not just rice in a different shape. The key difference lies in how it is made.
Rice used in ketupat is packed tightly into woven palm leaf or coconut leaf pouches and boiled for an extended period, producing a dense, compressed cake that is then typically left to cool before being served.
This cooling process is where the science gets interesting. When cooked rice cools, a phenomenon called starch retrogradation occurs, in which amylose and amylopectin molecules in the starch reassemble into a more ordered, crystalline structure that is harder for digestive enzymes to break down, according to a peer-reviewed study published in the journal Nutrients.
This retrograded starch becomes what is known as resistant starch, a type of starch that resists digestion in the small intestine and therefore results in a lower glycaemic response, according to research published in PMC by the National Institutes of Health.
A peer-reviewed clinical study published in PMC found that when patients with type 1 diabetes ate rice that had been cooked and then cooled for 24 hours, they recorded significantly lower maximum blood glucose levels compared with those who ate freshly cooked rice.
The dense, compressed structure of ketupat also means it is digested more slowly than loosely cooked white rice, as the tightly packed starch granules are less accessible to digestive enzymes, according to a systematic review published in the British Journal of Nutrition examining how rice processing methods affect glycaemic response.
The type of rice used matters too. Higher amylose content in rice is associated with a lower GI, as amylose has a linear structure that is more resistant to digestion than the branched amylopectin found in higher concentrations in glutinous and short-grain rice varieties, according to research published in PMC.
That said, none of this means Malaysians should treat ketupat as a health food or a free pass during Hari Raya feasting. Portion size remains critical.
The glycaemic load, which accounts for both the GI and the total amount of carbohydrates consumed, rises with every additional piece, and eating large quantities of even lower-GI foods can still raise blood sugar significantly.
The real danger at the Hari Raya table is not the ketupat alone, but the combination: ketupat eaten with rendang, kuah kacang, lodeh and serunding in large quantities adds up to a substantial carbohydrate and calorie load that no amount of retrogradation can fully offset.
For the estimated 3.9 million Malaysians living with diabetes, and the many more with prediabetes, enjoying ketupat in moderation rather than avoiding it entirely is the more realistic and science-backed approach.
Sources:
1. https://pmc.ncbi.nlm.nih.
2. https://pmc.ncbi.nlm.nih.
3. https://pmc.ncbi.nlm.nih.
5. https://www.health.harvard.
6. https://pmc.ncbi.nlm.nih.
7. https://pmc.ncbi.nlm.nih.
10. https://pmc.ncbi.nlm.nih.
