India’s carb-heavy diets fuel diabetes, obesity surge: ICMR study

CHENNAI:A significant ICMR–INDIAB study, published in Nature Medicine, has sounded a national health alarm, revealing that India’s carb-heavy diets — dominated by white rice, milled grains, and added sugars — are sharply escalating the risk of diabetes, prediabetes, and obesity across regions.

Conducted by the Indian Council of Medical Research (ICMR) in collaboration with the Madras Diabetes Research Foundation (MDRF), the 15-year study (funded by the Union health ministry) analysed data from over 1.21 lakh adults across 36 states and Union Territories, offering the most comprehensive evidence yet on how India’s evolving dietary profile is driving metabolic disease.

Researchers found that 62% of daily calories in Indian diets come from carbohydrates, one of the highest proportions globally. Most of these calories stem from low-quality sources — white rice, refined grains, and added sugars.

While white rice dominates diets in the South, East, and Northeast, wheat remains more common in the North and Central regions. Millets are main staples only in Karnataka, Gujarat, and Maharashtra, despite their nutritional advantages. Alarmingly, 21 states and UTs exceeded national sugar intake limits.

India’s protein intake remains suboptimal, averaging 12% of daily calories, with plant-based foods (9%) forming the bulk. Dairy contributes around 2%, animal protein just 1%, and highest intakes (14%) are seen only in the Northeast.

Total fat intake stays within guidelines (≤30% of energy), but saturated fat intake exceeds safe thresholds in all but four states — Jharkhand, Chhattisgarh, Arunachal Pradesh, and Manipur. Meanwhile, intakes of mono-unsaturated and omega-3 poly-unsaturated fats remain critically low nationwide.

Modelled analysis revealed that replacing just 5% of daily calories from carbohydrates with plant or dairy proteins can significantly reduce the risk of developing diabetes and prediabetes. Notably, red meat proteins or fats did not show similar protective benefits.

Lead author Dr RM Anjana, president, MDRF, said, “Typical Indian diets, high in refined carbs and low in quality proteins, are putting millions at risk. Simply switching from white rice to millets isn’t enough unless total carb intake drops and protein quality improves.”

Co-author and senior scientist Sudha Vasudevan, MDRF, concurred, and added: “Metabolic risks are consistent across all regions, irrespective of staple foods.”

Senior author Dr V Mohan, chairman, MDRF, urged policy reforms to realign food subsidies and public messaging. “This requires a multi-sectoral approach spanning health, agriculture, food processing, and welfare to promote nutritionally balanced diets,” he opined.

Co-senior author Dr Shilpa Bhupathiraju stressed on “reducing saturated fats while encouraging healthier oils, pulses, and legumes could transform India’s nutrition landscape”.

In Tamil Nadu, where polished white rice dominates meals, health experts warn of heightened vulnerability. Earlier urban studies in Chennai recorded a diabetes incidence rate of 20.2 per 1,000 person-years, among the highest in India — a trend linked to refined carb-heavy diets and low protein diversity.

Promoting millets, pulses, legumes, and dairy, alongside reducing sugar and refined grains, is seen as critical to reversing the State’s trajectory.

A parallel Nature Medicine global analysis estimates that 24.6% of Type 2 diabetes cases worldwide stem from excess refined rice and wheat intake, while 26.1% result from insufficient whole grains — patterns mirroring India’s dietary imbalance.

WHAT THE STUDY REVEALS

Data analysed from over 1.21 lakh adults across 36 states and Union Territories for 15 years

· 62% of calories from carbohydrates — among world’s highest

· Low-quality sources — white rice, refined grains, and added sugars — source of most of these calories

· White rice dominates diets in South, East, and Northeast

· Wheat common in North and Central regions

· Millets main staple only in Karnataka, Gujarat and Maharashtra

· 21 states, UTs exceed national sugar intake limits

· Protein intake sub-optimal at 12% average of daily calories

· Plant-based foods at 9%

· Dairy around 2%

· Animal protein just 1%

· Highest intakes (14%) only in Northeast

· Total fat intake within guidelines -≤30% of energy

· Saturated fat intake exceeds safe thresholds in Jharkhand, Chhattisgarh, Arunachal Pradesh and Manipur

· Saturated fat high, healthy fats low

· 5% carb-to-protein swap cuts risk