Waist size or BMI? Apollo neurologist exposes which number predicts heart danger

Many people obsess over BMI, but a leading neurologist now says the real danger might be hiding around your waist. Apollo neurologist Dr Sudhir Kumar took to X to explain why waist circumference is often a far more accurate warning sign for heart disease, diabetes and metabolic issues than the weight-height formula most of us grew up trusting. His post quickly grabbed attention, especially among Indians who face higher risks at lower fat levels.

Dr Kumar explained that waist circumference reflects visceral fat, the harmful fat wrapped around internal organs, making it a stronger predictor of metabolic and cardiovascular problems. He highlighted clear cut-offs for South Asian populations: under 90 cm for men and under 80 cm for women. These numbers are tighter than Western standards because Indians are prone to developing diabetes, hypertension and heart disease even with moderate fat gain.

Why waist circumference beats BMI?

He also broke down why BMI falls short. It can’t differentiate between muscle and fat, it ignores fat distribution, and it misses people who appear healthy but carry excess fat around the abdomen. According to Dr Kumar, individuals with a normal BMI but a high waist measurement face two to three times higher risk of diabetes, fatty liver and heart disease. He stressed that central obesity is one of the strongest predictors of mortality after smoking.



His message for the public was straightforward: a normal BMI doesn’t guarantee safety if the waist is expanding. For Indians, keeping waist size within recommended limits is one of the simplest ways to protect the heart, liver and pancreas.

What do studies say?

According to the National Library of Medicine, waist size needs a place in everyday checkups because it captures health risks that BMI alone often misses. Research shows it predicts disease and mortality more accurately and changes reliably with regular exercise and diet. It’s simple to measure, even at home, and aligns closely with technician results. Thresholds may need fine-tuning for age, sex, and ethnicity, but the evidence is strong enough already: clinicians should treat waist circumference as a core vital sign and use it to guide prevention and care.