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

A Retrospective Study of Individual Glycemic Response Based on CGM Wearable Devices in Weight and Body Composition Management Among College Students

This retrospective study evaluates the real-world effect of individualized glycemic response-guided dietary management, based on continuous glucose monitoring (CGM), on weight and body composition in overweight and obese university students. All data for this analysis were retrospectively retrieved from the archived records of a randomized controlled trial conducted at He University, in which 60 students (body mass index [BMI] ≥ 24 kg/m² or elevated body fat percentage) had worn CGM sensors for 4 weeks. The archived records show that the exposed group (n = 30) had received individualized dietary guidance generated from their own glucose responses, including structured CGM reports, meal composition and eating-order advice, and standardized feedback, whereas the non-exposed group (n = 30) had worn CGM without receiving any dietary guidance. One non-exposed participant was excluded from this retrospective analysis for missing primary outcome data, leaving 59 participants for analysis. The archived dataset contains body composition (weight, body mass index [BMI], body fat mass, percent body fat, skeletal muscle mass, visceral fat level) and eating behavior records at Day 0, Day 28, and Day 90. This analysis examines whether the 4-week intervention produced sustained, fat-mass-driven improvements in body composition and whether changes in eating behavior mediated these effects.

Study Overview

• Status: Completed
• Conditions: Weight Loss; Overweight , Obesity

Detailed Description

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.

• Study Type: Observational
• Enrollment (Actual): 59

Contacts and Locations

Study Locations

• China
  • Liaoning
    • Shenyang, Liaoning, China
      • He University, Shenyang, Liaoning, China

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Overweight and obese university students (aged 18-25 years) at He University, Shenyang, Liaoning, China, whose records are contained in the archived dataset of a randomized controlled trial of a 4-week continuous glucose monitoring (CGM)-guided personalized dietary intervention. Participants had a body mass index (BMI) ≥ 24 kg/m² or elevated body fat percentage (≥ 25% in men, ≥ 32% in women) and self-reported at least two unhealthy eating behaviors. Of the 60 participants enrolled in the parent trial (30 per group), 59 were included in this retrospective analysis (30 exposed, 29 non-exposed); one non-exposed participant was excluded for missing primary outcome data. All participants were free of diabetes, prediabetes, and other exclusion conditions defined in the study protocol.

Description

Inclusion Criteria:

• University students aged 18 to 25 years
• Body mass index (BMI) ≥ 24.0 kg/m², or body fat percentage ≥ 25% (male) / ≥ 32% (female)
• Self-reported presence of at least two unhealthy eating behaviors
• Written informed consent

Exclusion Criteria:• Obesity due to endocrine diseases (e.g., Cushing's syndrome, hypothyroidism, hypothalamic obesity) or genetic syndromes

• Polycystic ovary syndrome (PCOS)
• Weight gain or glycemic abnormality induced by medications (e.g., glucocorticoids, antipsychotics, insulin secretagogues)
• Diagnosed diabetes (type 1 or type 2) or prediabetes (fasting glucose ≥ 6.1 mmol/L or glycated hemoglobin (HbA1c)≥ 5.7%)
• Diagnosed dyslipidemia with lipid-lowering medication
• High risk of eating disorders identified by the Eating Disorder Diagnostic Scale (EDDS)
• Severe psychiatric disorders or psychotropic medication use
• Pregnancy, lactation, or planned pregnancy within 6 months
• Allergy to CGM adhesive or hydrogel, or active skin disease affecting sensor wear
• Professional athletes (high-intensity physical activity ≥ 5 times/week, ≥ 60 min/session)
• Weight change > 5% of initial body weight within the past 3 months
• Participation in other commercial or clinical weight-loss programs

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Exposed (n=30); Participants whose archived records from the parent trial indicate that they had received a 4-week individualized glycemic response-guided dietary intervention based on continuous glucose monitoring (CGM) data: dietary behavior observation during weeks 1-2, followed by structured CGM reports, dietary guidance on meal composition and eating order, and standardized researcher feedback during weeks 3-4.
Non-exposed (n=29); Participants whose archived records from the parent trial indicate that they had worn the CGM system for 4 weeks without receiving dietary guidance or feedback. CGM data were visible during weeks 1-2 and blinded during weeks 3-4. Participants maintained their usual diet and lifestyle. One of the 30 non-exposed participants enrolled in the parent trial was excluded from this retrospective analysis for missing primary outcome data.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time above range (TAR)	Change in the percentage of time above the target glucose range recorded in the archived CGM dataset. Unit of Measure: Percent of time (%).	Data recorded at baseline, Day 14, and Day 28
Body weight	Change in body weight recorded in the archived InBody 120 dataset. Unit of Measure: Kilogram (kg).	Data recorded at Day 0, Day 28, and Day 90

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body fat mass	Change in total body fat mass derived from the archived InBody 120 records. Unit of Measure: Kilogram (kg).	Data recorded at Day 0, Day 28, and Day 90
Body mass index (BMI)	Change in body mass index, calculated as body weight in kilograms divided by the square of body height in meters, derived from the archived InBody 120 records. Unit of Measure: Kilogram per square meter (kg/m²).	Data recorded at Day 0, Day 28, and Day 90
Percent body fat	Change in body fat percentage, calculated as body fat mass divided by total body weight, derived from the archived InBody 120 records. Unit of Measure: Percent (%).	Data recorded at Day 0, Day 28, and Day 90
Skeletal muscle mass	Change in skeletal muscle mass derived from the archived InBody 120 records. Unit of Measure: Kilogram (kg).	Data recorded at Day 0, Day 28, and Day 90
Visceral fat level	Change in visceral fat level derived from the archived InBody 120 records. Scale range: minimum 1, maximum 20; higher levels indicate greater visceral adiposity (worse). Unit of Measure: InBody visceral fat level (unitless scale, 1-20).	Data recorded at Day 0, Day 28, and Day 90
Waist circumference	Change in waist circumference derived from the archived anthropometric records. Unit of Measure: Centimeter (cm).	Data recorded at Day 0, Day 28, and Day 90
Hip circumference	Change in hip circumference derived from the archived anthropometric records. Unit of Measure: Centimeter (cm).	Data recorded at Day 0, Day 28, and Day 90
Waist-hip ratio	Change in waist-hip ratio, calculated as waist circumference divided by hip circumference, derived from the archived anthropometric records. Unit of Measure: Ratio (unitless).	Data recorded at Day 0, Day 28, and Day 90
Time in range (TIR)	Change in the percentage of time within the target glucose range derived from the archived CGM records. Unit of Measure: Percent of time (%).	Data recorded from Day 0 to Day 28
Average glucose (AG)	Change in average glucose derived from the archived CGM records. Unit of Measure: Millimole per liter (mmol/L).	Data recorded from Day 0 to Day 28
Coefficient of variation (CV)	Change in the coefficient of variation of glucose derived from the archived CGM records. Unit of Measure: Percent (%).	Data recorded from Day 0 to Day 28
DEBQ restrained eating subscale	Change in the restrained eating subscale score of the Dutch Eating Behavior Questionnaire (DEBQ), scored as the mean of its item ratings on a scale from 1 (minimum) to 5 (maximum), derived from the archived records. Higher scores indicate a greater tendency toward restrained eating; in this study, increases in this score were considered favorable (better dietary self-regulation). Unit of Measure: Subscale score (1-5).	Data recorded at Day 0, Day 28, and Day 90
DEBQ emotional eating subscale	Change in the emotional eating subscale score of the Dutch Eating Behavior Questionnaire (DEBQ), scored as the mean of its item ratings on a scale from 1 (minimum) to 5 (maximum), derived from the archived records. Higher scores indicate a greater tendency to eat in response to negative emotions; in this weight-management context, higher scores are considered unfavorable (worse outcome). Unit of Measure: Subscale score (1-5).	Data recorded at Day 0, Day 28, and Day 90
DEBQ external eating subscale	Change in the external eating subscale score of the Dutch Eating Behavior Questionnaire (DEBQ), scored as the mean of its item ratings on a scale from 1 (minimum) to 5 (maximum), derived from the archived records. Higher scores indicate a greater tendency to eat in response to external food cues; in this weight-management context, higher scores are considered unfavorable (worse outcome). Unit of Measure: Subscale score (1-5).	Data recorded at Day 0, Day 28, and Day 90
Eating Disorder Diagnostic Scale (EDDS) score	Change in the Eating Disorder Diagnostic Scale (EDDS) symptom composite score derived from the archived records. Scale range: minimum 0, maximum 227; higher scores indicate more severe eating disorder symptoms (worse outcome). Unit of Measure: Score (0-227).	Data recorded at Day 0, Day 28, and Day 90
Pittsburgh Sleep Quality Index (PSQI) score	Change in the Pittsburgh Sleep Quality Index (PSQI) global score derived from the archived records. Scale range: minimum 0, maximum 21; higher scores indicate poorer sleep quality (worse outcome). Unit of Measure: Score (0-21).	Data recorded at Day 0, Day 28, and Day 90
Perceived Stress Scale (PSS-10) score	Change in the Perceived Stress Scale (PSS-10) total score derived from the archived records. Scale range: minimum 0, maximum 40; higher scores indicate greater perceived stress (worse outcome). Unit of Measure: Score (0-40).	Data recorded at Day 0, Day 28, and Day 90
Traditional Chinese Medicine (TCM) balanced constitution score	Change in the balanced constitution score of the Constitution in Chinese Medicine Questionnaire (CCMQ), transformed to a 0-100 scale per the standard scoring formula, derived from the archived records. Scale range: minimum 0, maximum 100; higher scores indicate a more balanced constitution (better outcome). Unit of Measure: Score (0-100).	Data recorded at Day 0, Day 28, and Day 90
TCM qi-deficiency constitution score	Change in the qi-deficiency constitution score of the Constitution in Chinese Medicine Questionnaire (CCMQ), transformed to a 0-100 scale per the standard scoring formula, derived from the archived records. Scale range: minimum 0, maximum 100; higher scores indicate stronger expression of this constitution type, i.e., greater constitutional imbalance (worse outcome). Unit of Measure: Score (0-100).	Data recorded at Day 0, Day 28, and Day 90
TCM yang-deficiency constitution score	Change in the yang-deficiency constitution score of the Constitution in Chinese Medicine Questionnaire (CCMQ), transformed to a 0-100 scale per the standard scoring formula, derived from the archived records. Scale range: minimum 0, maximum 100; higher scores indicate stronger expression of this constitution type, i.e., greater constitutional imbalance (worse outcome). Unit of Measure: Score (0-100).	Data recorded at Day 0, Day 28, and Day 90
TCM yin-deficiency constitution score	Change in the yin-deficiency constitution score of the Constitution in Chinese Medicine Questionnaire (CCMQ), transformed to a 0-100 scale per the standard scoring formula, derived from the archived records. Scale range: minimum 0, maximum 100; higher scores indicate stronger expression of this constitution type, i.e., greater constitutional imbalance (worse outcome). Unit of Measure: Score (0-100).	Data recorded at Day 0, Day 28, and Day 90
TCM phlegm-dampness constitution score	Change in the phlegm-dampness constitution score of the Constitution in Chinese Medicine Questionnaire (CCMQ), transformed to a 0-100 scale per the standard scoring formula, derived from the archived records. Scale range: minimum 0, maximum 100; higher scores indicate stronger expression of this constitution type, i.e., greater constitutional imbalance (worse outcome). Unit of Measure: Score (0-100).	Data recorded at Day 0, Day 28, and Day 90
TCM damp-heat constitution score	Change in the damp-heat constitution score of the Constitution in Chinese Medicine Questionnaire (CCMQ), transformed to a 0-100 scale per the standard scoring formula, derived from the archived records. Scale range: minimum 0, maximum 100; higher scores indicate stronger expression of this constitution type, i.e., greater constitutional imbalance (worse outcome). Unit of Measure: Score (0-100).	Data recorded at Day 0, Day 28, and Day 90
TCM blood-stasis constitution score	Change in the blood-stasis constitution score of the Constitution in Chinese Medicine Questionnaire (CCMQ), transformed to a 0-100 scale per the standard scoring formula, derived from the archived records. Scale range: minimum 0, maximum 100; higher scores indicate stronger expression of this constitution type, i.e., greater constitutional imbalance (worse outcome). Unit of Measure: Score (0-100).	Data recorded at Day 0, Day 28, and Day 90
TCM qi-stagnation constitution score	Change in the qi-stagnation constitution score of the Constitution in Chinese Medicine Questionnaire (CCMQ), transformed to a 0-100 scale per the standard scoring formula, derived from the archived records. Scale range: minimum 0, maximum 100; higher scores indicate stronger expression of this constitution type, i.e., greater constitutional imbalance (worse outcome). Unit of Measure: Score (0-100).	Data recorded at Day 0, Day 28, and Day 90
TCM special diathesis constitution score	Change in the special diathesis constitution score of the Constitution in Chinese Medicine Questionnaire (CCMQ), transformed to a 0-100 scale per the standard scoring formula, derived from the archived records. Scale range: minimum 0, maximum 100; higher scores indicate stronger expression of this constitution type, i.e., greater constitutional imbalance (worse outcome). Unit of Measure: Score (0-100).	Data recorded at Day 0, Day 28, and Day 90
Right arm fat mass	Change in body fat mass of the right arm derived from the archived InBody 120 records. Unit of Measure: Kilogram (kg).	Data recorded at Day 0, Day 28, and Day 90
Left arm fat mass	Change in body fat mass of the left arm derived from the archived InBody 120 records. Unit of Measure: Kilogram (kg).	Data recorded at Day 0, Day 28, and Day 90
Trunk fat mass	Change in body fat mass of the trunk derived from the archived InBody 120 records. Unit of Measure: Kilogram (kg).	Data recorded at Day 0, Day 28, and Day 90
Right leg fat mass	Change in body fat mass of the right leg derived from the archived InBody 120 records. Unit of Measure: Kilogram (kg).	Data recorded at Day 0, Day 28, and Day 90
Left leg fat mass	Change in body fat mass of the left leg derived from the archived InBody 120 records. Unit of Measure: Kilogram (kg).	Data recorded at Day 0, Day 28, and Day 90

Collaborators and Investigators

• Sponsor: He Eye Hospital
• Investigators: Principal Investigator: Jun Li, MD, He University, Shenyang, Liaoning, China

Study record dates

Study Major Dates

• Study Start (Actual): June 27, 2026
• Primary Completion (Actual): July 30, 2026
• Study Completion (Actual): August 15, 2026

Study Registration Dates

• First Submitted: August 25, 2026
• First Submitted That Met QC Criteria: September 8, 2026
• First Posted (Actual): September 14, 2026

Study Record Updates

• Last Update Posted (Actual): September 14, 2026
• Last Update Submitted That Met QC Criteria: September 8, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: body composition; university students; continuous glucose monitoring; personalized nutrition; eating behavior; retrospective study
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Body Weight Changes; Pathological Conditions, Signs and Symptoms; Behavior; Nutritional and Metabolic Diseases; Signs and Symptoms; Behavior, Animal; Overweight; Obesity; Weight Loss; Feeding Behavior
• Other Study ID Numbers: IRB(2026)K005.01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No