Weight-for-squared height or body mass index (BMI) is often considered as an effective predictor of morbidity and mortality rates. This study uses BMI data from a sample of ever-married women in the age group of 15-49 years in the North Indian state of Uttar Pradesh for the year 1998-1999, to analyse the determinants of chronic energy deficiency (CED) and estimate the population vulnerable to CED. The results highlight that CED rates and vulnerability rates can be very different, emphasizing need for policy intervention to focus on "potential" CED persons. The characteristics of vulnerable population identified would be appropriate channels for policy intervention.