Retrospective Continuous Glucose Monitor (CGM) Study on Glycemic Response and Body Composition in College Students

Background: continuous glucose monitoring (CGM) technology is expanding from diabetes care to weight management in healthy populations. Individualized glycemic response-guided dietary management may improve weight loss efficiency, but whether a brief 4-week intervention produces sustained body composition benefits remains unclear. Design: This is a retrospective analysis of data collected in a two-arm, parallel-group randomized controlled trial conducted at He University, Shenyang, China. No new intervention was administered and no new measurements were performed in the present study; all data were retrospectively extracted from existing archived records. Participants were classified into two cohorts according to the exposure documented in the archived data of the parent trial. The archived records document that 60 overweight or obese university students (aged 18-25 years) had been randomized 1:1 by a random number table in the parent trial, and that both groups had worn the GX-01S continuous glucose monitoring system for 4 weeks (28 days). The archived records show that the exposed group had received an individualized glycemic response-guided dietary intervention: weeks 1-2 served as a dietary behavior observation period (CGM glucose profiles and electronic food diaries), and weeks 3-4 comprised the individualized intervention, including structured CGM reports (glucose trend graphs, traffic-light food lists, individually glucose-sensitive time windows), dietary guidance on meal composition and eating order, and standardized researcher feedback. The archived records show that the non-exposed group had worn CGM without dietary guidance; CGM data were visible during weeks 1-2 and blinded during weeks 3-4. Assessments: The archived dataset contains body composition measurements recorded with the InBody 120 bioelectrical impedance analyzer at Day 0 (baseline), Day 28 (end of the 4-week period), and Day 90 (follow-up), together with Dutch Eating Behavior Questionnaire (DEBQ) records at the same three timepoints. All values were retrospectively extracted; no additional measurement was performed for this study. Outcomes: Primary outcomes of the parent study were time above range (TAR) change and body weight change, both derived from the archived records. This analysis focuses on body composition outcomes: weight, body mass index (BMI), percent body fat, body fat mass, skeletal muscle mass, visceral fat level, and segmental body fat across five body compartments, together with exploratory mediation analyses testing whether DEBQ subscale changes (restrained, emotional, and external eating) mediated the intervention effect. Ethics: The parent study was approved by the Institutional Ethics Committee of He University, and all participants provided written informed consent. For this retrospective analysis of anonymized data, the ethics committee approved a waiver of renewed informed consent.