Summary We explore the suitability of the adult Body Mass Index (BMI) to measure health and nutritional inequalities between and within households. The paper applies a macro analysis comparing female BMIs at the country level and a micro-analysis comparing females' and males' BMI in Vietnam. At macro level, we estimated an analogue of the Kuznets curve finding a U-shaped relation between development (Human Development Index) and health and nutritional inequality (female BMI). At micro level, we use the panel data characteristics of the Vietnam dataset and show how income improvements registered in the 1990s benefited males considerably more than females.