Behavioral and Psychosocial Effects of Participant-Visible Continuous Glucose Monitoring in Adults Without Diabetes: A Systematic Review.

Background and Objectives: Continuous glucose monitoring (CGM) is increasingly used beyond diabetes care, but whether participant-visible feedback changes behavior or psychosocial outcomes in adults without diabetes remains uncertain. We evaluated dietary behavior/adherence, physical activity, psychosocial outcomes, and device burden. Materials and Methods: This PROSPERO-registered systematic review (CRD420261356163) searched seven bibliographic databases and two trial registries, followed by citation searching. Randomized and nonrandomized intervention studies and qualitative/mixed-methods evidence were eligible. RoB 2, ROBINS-I, MMAT 2018, and GRADE were applied. Clinical and methodological heterogeneity precluded meta-analysis. Results: Searches yielded 6265 database/registry records; 2627 unique records were screened. Citation searching added 431 new records and two eligible studies, giving 12 studies. Two randomized dietary comparisons suggested selected improvements; one 8-week trial comparing CGM plus low-glycemic-index/load education with education alone reported between-group reductions in carbohydrate intake (-15.2 g; 95% CI -20.9 to -9.5), glycemic index (-10.0; 95% CI -13.1 to -6.9), and glycemic load (-19.9; 95% CI -29.0 to -10.7). Physical activity showed no clear difference (-28.5 MET-min/week; 95% CI -171.9 to 114.8). Psychosocial evidence was insufficient to establish benefit or exclude harm; device burden evidence was sparse. Certainty was low for dietary outcomes and very low for the other domains. Conclusions: Participant-visible CGM may support selected dietary changes as a biofeedback adjunct within structured education or lifestyle interventions, but large, durable benefits and stand-alone efficacy are not established.