Adolescents, pregnant women and mothers of children under 2 years of age are in stages of life characterized by higher nutritional demands. The study measured the dietary diversity of 17,680 adolescent girls, pregnant women and mothers of children under age 2 years in the eastern Indian states of Bihar, Chhattisgarh and Odisha using data from the Swabhimaan baseline survey conducted in 2016. The association of women’s mean Dietary Diversity Scores with socioeconomic, health and nutrition service indicators was assessed. The sampled population was socioeconomically more vulnerable than the average Indian population. There was not much variation in the types of foods consumed daily across target groups, with diet being predominantly cereal (98%) and vegetable (83%) based. Nearly 30% of the mothers had low Dietary Diversity Scores, compared with 25% of pregnant women and 24% of adolescent girls. In each target group, more than half of the respondents were unable to meet the Minimum Dietary Diversity score of at least five of ten food groups consumed daily. Irrespective of their background characteristics, mean Dietary Diversity Scores were significantly lower in Bihar than in Chhattisgarh and Odisha for all target groups. Having at least 6 years of education, belonging to a relatively rich household and possessing a ration card predicted mean dietary diversity. Project interventions of participatory women’s group meetings improved mean Dietary Diversity Scores for mothers and adolescent girls. Considering the association between poverty and dietary diversity, the linkage between girls and women and nutrition-focused livelihoods and supplementary nutrition programmes needs to be tested.