Introduction: Other than for agreement that own mother's milk is the optimum feed, nutritional practice for very preterm babies varies widely. As part of the development of a randomised controlled trial to address preterm nutrition uncertainties, and with the help of the European Foundation for the Care of Newborn Infants (EFCNI), we sought the views of parents across Europe., Methods: We held two roundtable discussions about the proposed trial, inviting the participation of parents and preterm adults through EFCNI. We sought their views and prior knowledge of preterm nutrition uncertainties, treatment comparisons and opinions on specific aspects of design such as cluster versus individual randomisation. We used thematic Framework Analysis to explore the data., Results: There were 11 participants (two men and nine women) from six European countries. Nine were parents and two were preterm adults. Participants strongly supported the need for research to improve care. However, we found little knowledge of methods to resolve uncertainties in care, and wide variation in information provided to parents during their baby's neonatal unit stay. No parent recalled a member of the clinical staff having told them about nutrition uncertainties., Conclusions: Present-day best practice is to involve parents, patients, and the public in all stages of clinical research from design to dissemination and implementation. To strengthen involvement and participation we suggest there is need to improve knowledge of research methods. Clinicians may find it helpful to receive training on how to explain clinical uncertainties, and methods to resolve these., Competing Interests: Declaration of competing interest The EFCNI receives funding from nutrition companies but no co-authors receive any honorarium. NM reports grants from Medical Research Council, grants from National Institute for Health Research, grants from Prolacta Life Sciences, grants from Chiesi International, grants from Westminster Children's Research Trust, grants from European Health Data and Evidence Network, grants from HCA International, grants from Health Data Research UK, grants from Shire Pharmaceuticals, grants from March of Dimes, outside the submitted work. All other authors have no interests to declare., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)