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5 min readExpert-reviewedUpdated 4 Jun 2026

Why does dal-chawal spike my blood sugar but not my sister's?

Same comfort meal, two very different glucose curves.

Short answer

Dal-chawal can spike your blood sugar but not your sister's because of differences in the AMY1 gene that sets how much starch-digesting enzyme you make, plus TCF7L2 and FTO variants that shape insulin response, so the same rice raises glucose more sharply in some people.

Key takeaways
  • AMY1 copy number changes how much starch-digesting enzyme you make.
  • TCF7L2 is a leading diabetes-risk gene affecting insulin release.
  • These variants are common in South Asians on rice-heavy diets.
  • More dal, protein first, and a post-meal walk flatten the same spike.

Digestion of rice starch begins in your mouth, driven by salivary amylase, an enzyme whose amount depends on how many copies of the AMY1 gene you carry. People with fewer copies break down starch differently, which can change how fast glucose hits the bloodstream. Your sister may simply make more amylase, or handle the glucose load more smoothly, even on the identical plate of dal-chawal.

The bigger driver is insulin. The TCF7L2 gene is one of the strongest known influences on type 2 diabetes risk and on how well your pancreas releases insulin in response to carbs. FTO adds appetite and fat-storage effects on top. These variants are common in South Asians, and combined with a traditionally rice- and wheat-heavy diet, they help explain why Indians develop diabetes at younger ages and lower body weights than many other populations. So two siblings can share most of their DNA yet inherit different combinations that tip blood sugar in opposite directions.

The honest takeaway: you do not have to give up dal-chawal. Add more dal and vegetables relative to rice, choose hand-pounded or parboiled rice, eat protein first, and take a short walk after eating. These steady the same spike that genetics makes sharper for you. Your sister's smoother curve is luck of the draw, not proof you are doing something wrong.

People also ask

Should I stop eating rice if it spikes my sugar?

No. Reduce the portion, add dal, vegetables and protein, and walk after eating; the meal balance matters more than removing rice entirely.

Does TCF7L2 mean I will get diabetes?

It raises risk, not certainty. Many people with the variant never develop diabetes, especially with steady activity, weight management and balanced meals.

Which rice is gentler on blood sugar?

Parboiled, hand-pounded or higher-fibre rice and pairing rice with dal and vegetables generally produce a gentler glucose rise than plain polished white rice.

Sources
  • Grant SFA et al., Nature Genetics 2006 - TCF7L2 and type 2 diabetes
  • Falchi M et al., Nature Genetics 2014 - AMY1 copy number and metabolism
  • ICMR-INDIAB - diabetes prevalence and onset age in India

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