Digital Interventions Targeting Healthy and Sustainable Eating Behavior: Systematic Review and Meta-Analysis.

Background: Current food consumption patterns contribute to the rising prevalence of obesity and noncommunicable diseases and exacerbate environmental degradation. Digital media offer promising opportunities to promote healthier and more sustainable eating; yet, evidence regarding their effectiveness remains fragmented. Objective: The aim of this systematic review and meta-analysis is (1) to evaluate the effectiveness of digital interventions in improving healthy and sustainable food consumption and (2) to identify which participant and intervention characteristics are associated with greater effectiveness. Methods: A systematic search was conducted in January 2024 and repeated in September 2025 across Web of Science, Embase, and Scopus, supplemented with forward and backward reference searching. Eligible studies were those with a quasi-experimental or longitudinal design evaluating digital interventions targeting nonclinical populations, with the aim of increasing plant-based food consumption or reducing animal-based food intake. Risk of bias was assessed using the Cochrane risk-of-bias tool. Included interventions were coded for behavior change techniques using the Behavior Change Taxonomy version 1. A random-effects meta-analysis with robust variance estimation was performed, and moderator analyses were conducted with participant and intervention characteristics. Results: Eligibility screening led to the inclusion of 52 papers published between 2004 and 2025, with 24,652 participants in total. The meta-analysis revealed a small but statistically significant positive effect of digital interventions on food consumption outcomes (d=0.33, 95% CI 0.25-0.42; P<.001). However, substantial heterogeneity (I2=86%, 95% prediction interval -0.21 to 0.87) indicates considerable variation in effectiveness across intervention characteristics. A moderator analysis showed no significant difference in effectiveness (P=.53) between interventions aimed at reducing meat consumption (d=0.38, 95% CI 0.20-0.57; P<.001) and those promoting plant-based eating (d=0.33, 95% CI 0.23-0.42; P<.001). Although digital interventions had the strongest effects among young adults (d=0.46, 95% CI 0.30-0.61; P<.001), age-related differences were not statistically significant. Intervention effectiveness differed significantly by platform (P=.03), with social media interventions (d=0.65, 95% CI 0.41-0.90; P<.001) yielding stronger effects than other modalities. Incorporating prompts or cues significantly enhanced effectiveness (d=0.58 vs d=0.30; P=.04). Although not statistically significant, interventions including social support or behavioral comparison (both d=0.39; P<.001) yielded larger effects. Few studies included adolescents or individuals from lower socioeconomic backgrounds. Conclusions: This review underscores the innovative potential of digital interventions in improving eating behavior, highlighting how effectiveness varies by intervention design. Social media emerge as particularly promising, likely due to their unique social and interactive features. By pinpointing the contexts and types of digital interventions that most effectively promote plant-based eating, this study provides timely guidance for researchers and practitioners in increasingly digitalized food environments. Nonetheless, more high-quality studies are needed to confirm these insights and address the critical gap among adolescents and low socioeconomic groups.