Introduction. Objective and accurate dietary monitoring is critical for comprehensive dietary assessment and improving nutritional health outcomes. The rapid development of wearable sensing technology presents a promising solution for effective dietary monitoring that reduces recall bias and increases user convenience, contributing to clinical chronic disease management and nutritional research. This systematic review aims to explore the effectiveness and practicality of wearable sensors in monitoring dietary behaviours, while also examining the latest advancements in the field since 2020. Methods and Analysis. Adhering to PRISMA-P guidelines, we will conduct a comprehensive search across MEDLINE, EMBASE, PubMed, IEEExplore, and Web of Science for research published between January 2020 and January 2024 Studies that involved human participants using wearable sensors for monitoring dietary intake will be included. However, studies solely discussing the development of algorithms or applications for these sensors will be excluded. Our review outcomes focused on evaluating the design of the sensors, their performance metrics, and user experience. Ethics and Dissemination. Findings of this systematic review will be disseminated through peer-reviewed journals, conferences, and seminar presentations. The data used does not include individual patient data, so no ethical approval is required. Systematic Review Registration Number. PROSPERO Registration ID: CRD42024531570