BACKGROUND: The participant recruitment process is a key ethical pivot point when conducting robust research. There is a need to continuously review and improve recruitment processes in research trials and to build fair and effective partnerships between researchers and participants as an important core element in ensuring the ethical delivery of high-quality research. When participants make a fair, informed, and voluntary decision to enroll in a study, they agree to fulfill their roles. However, supporting study participants to fulfill study requirements is an important ethical obligation for researchers, yet evidenced as challenging to achieve. This paper reports on participants' motivations to volunteer and remain part of a dietary study conducted in Kasungu District, Malawi. METHODS: We conducted twenty in-depth interviews (with chiefs, religious leaders, trial participants, and health surveillance assistants), five systematic ethnographic observations, and fourteen focus group discussions with trial participants and their partners. Interviews were audio-recorded and transcribed verbatim. We used a grounded theory methodology to analyse data that included coding, detailed memo writing, and data interpretation. FINDINGS: The findings reveal that many participants had concerns during the trial. Thematically, experiences included anxieties, mistrust of researchers, rumours, fears of exploitation, and misconceptions. Anonymous concerns collected from the participants were reported to the trial team which enabled the researchers to appropriately support participants. Despite initial concerns, participants described being supported and expressed motivation to take up their role. CONCLUSION: These findings highlight a diverse map of multiple notions of what is ethically relevant and what can impact participation and retention within a study. The study has revealed how embedding a responsive approach to address participants' concerns and ethical issues can support trust relationships. We argue for the need to employ embedded ethics strategies that enhance informed consent, focus on participants' needs and positive experiences, and support researchers to fulfill their roles. This work highlights the need for research ethics committees to focus on the risks of undue influence and prevent exploitation especially in settings with a high asymmetry in resources and power between researcher and participant groups. TRIAL REGISTRATION: The Addressing Hidden Hunger with Agronomy (Malawi) trial was registered on 5th March 2019 (ISCRTN85899451).