Participants were categorised according to their BMI alongside their waist circumference or waist-to-hip ratio, with researchers then tracking rates of various cardiac conditions and deaths. Among those with a normal BMI, roughly five per cent had an elevated waist circumference, whilst 18 per cent displayed a high waist-to-hip ratio. Strikingly, nine per cent of those classified as obese actually had smaller waistlines and 45 per cent recorded a low waist-to-hip ratio. Conversely, obese participants with smaller waistlines showed no greater risk of cardiac events than normal-weight people with low waist circumference. She added: "Relying solely on BMI may result in misclassification of cardiovascular risk across a wide range of cardiovascular outcomes."