Picky eating is common during childhood but when enduring it may burden the child's as well as his or her parents' physical and mental wellbeing. The present project aims to investigate the development, maintenance, and consequences of clinical picky eating behaviors (recently defined as Avoidant/Restrictive Food Intake Disorder; ARFID) by studying bidirectional relations in emotional processing between children and parents. Three work packages are set up in 2,5 to 8-year-olds and their parents to (1) Systematically review literature on the role of parenting in feeding problems, (2) Prospectively study bidirectional relations between parental stress regulation strategies and picky eating in the community and their relation with socioemotional adjustment, (3) Investigate levels of distress during the course of mealtimes, parental strategies and picky eating on a momentary level in children with (sub)clinical ARFID and their parents. This proposal is innovative because of its transactional view and challenging methodology using a longitudinal, observational and ecological momentary assessment design with the inclusion of self-report, interview, video and psychophysiological assessments. Results may improve developmental models of feeding and eating disorders, inform screening and prevention efforts and set the stage for developing new interventions that target the emotional processes that maintain or aggreviate picky eating and its adverse outcomes in children and parents.