Application of Immediate Adaptive Intervention in Dietary Health Management: A Systematic Review (Preprint)

BACKGROUND With the development of mHealth technology, Just-in-Time Adaptive Interventions (JITAI), as a new type of intervention that leverages real-time data to provide personalized support, has gradually gained attention. Relying on terminals such as smartphones and wearable devices, this intervention can collect individuals’ physiological indicators and environmental context data in real time, and dynamically adjust the type and intensity of support content. However, current research related to JITAI faces issues including inconsistent definition of core elements, high heterogeneity in intervention design, and controversial evidence on effectiveness. Additionally, there is a lack of systematic sorting out of its feasibility and generalizability, requiring evidence integration to guide its optimization. OBJECTIVE To systematically review the application effect of Just-in-Time Adaptive Interventions (JITAI) in dietary health management, comprehensively analyze its impacts on diet-related behaviors and physiological indicators, and assess the certainty of existing evidence. METHODS Databases including PubMed, Embase, Scopus, CINAHL, and Web of Science were searched from their inception to August 20, 2025. The search terms included dietary health, dietary behavior, JITAI, EMA, and others. Two researchers independently conducted literature screening, data extraction, and quality assessment, sorted out participant characteristics, JITAI features, outcome measures, and other relevant content, and summarized these elements. RESULTS A total of 12 studies were ultimately included in this research. The study populations covered groups such as adults with overweight/obesity, patients with hypertension, young people with low fruit and vegetable intake, patients with type 1 diabetes, patients with kidney stones, hemodialysis patients, and individuals with binge-eating spectrum disorders. Intervention types mainly included smartphone app interventions, short message service (SMS) reminders, wearable device interventions, and context-aware location-triggered interventions. Most studies reported positive effects of JITAI, such as increasing fruit and vegetable intake, reducing sodium intake, improving uncontrolled eating behaviors, enhancing the automaticity of fluid intake, and decreasing the frequency of binge eating and compensatory behaviors in patients with eating disorders. Meanwhile, implementation barriers including insufficient device adaptability, differences in digital literacy, and limitations of GPS signals were also revealed. CONCLUSIONS Existing evidence suggests that JITAI-based dietary interventions may have potential value in promoting dietary behavior change. However, due to research heterogeneity and methodological limitations, the certainty of their effectiveness remains limited. In the future, it is necessary to design high-quality studies with more rigorous methodologies, standardized outcome measures, and sufficient follow-up periods to clarify the effectiveness of JITAI in dietary health management.