Anthropometric data available through National Nutrition Monitoring Bureau surveys/studies conducted by the National Institute for Nutrition were analysed to study body mass index (BMI:kg/m2) profiles of adults and relate them to various parameters such as the nutritional status of preschool children, socio-economic status, low birth weight and mortality. The results show that nearly one-half (49%) of adult Indian rural population is suffering from some grade of chronic energy deficiency (CED). The adults' household BMI and child's nutritional status are associated. Mean BMI values were lower in landless agricultural occupational groups and in low per capita income group households compared with cultivators, artisan and higher income groups. Mean birth weights showed definite differences between BMI classes (2500 g in grade III CED and 2800 g in the normal BMI group). The odds ratio for low birth weight (LBW) was found to be three times more in severe CED groups compared to normal BMI groups of mothers. The influence of BMI on the incidence of LBW was evident despite the confounding factors of parity and maternal age. The frequency distribution of BMI values of adults who had been malnourished at the age of 5 years was distinctly different from that of the well-nourished group. The mean BMI of the group who were malnourished as children was 16, while those who had been well nourished was now 21 on average. Data from affluent and well-grown Indians suggests that a cut-off point of 18 rather than 18.5 would be more appropriate to distinguish the nutritionally normal groups from the energy deficient group (CED).