- To examine the role of maternal worries about child underweight and undereating in mother-child feeding interactions with children having a feeding disorder (FD). Participants were 27 children diagnosed with nonorganic-based FD and 28 children without FD. Mothers were interviewed about their worries about child underweight and undereating. Mother-child interactions were videotaped during feeding. Maternal child weight-related worries acted as both a mediator and a moderator. The more negative mother-child interactions found in the FD group, compared to the control group, were explained by greater maternal worry regarding child underweight. Furthermore, mother-child interactions within the FD group were not at risk per se, but only when coupled with high maternal worries about children's underweight. Worry about child underweight partially explains the development of negative feeding interactions when having children with FD, signifying clinical implications for the treatment of FD.