A Waist Circumference and Body Fat Percentage Dual-Dimension Nine-Square Grid Model for Precision Obesity Management: A Randomized Controlled Trial in Overweight/Obese University Students

The 9-Box Performance Management Framework: Impacts on Body Weight Regulation and Exercise Behaviors in Graduate Students

The goal of this randomized controlled trial is to test whether a dual-dimensional 9-grid matrix intervention improves body composition and exercise adherence compared to standard aerobic exercise in overweight/obese college students. The main questions it aims to answer are:

Does the 9-grid model optimize fat distribution (measured by waist-hip ratio) and sustain body fat reduction better than traditional exercise?

Does dynamic risk stratification in the 9-grid system enhance long-term exercise adherence?

How does spatial migration of participants within the grid (quantified by centroid index G) reflect intervention efficacy?

Researchers will compare the 9-grid management group (receiving dynamic positioning + 5-tier personalized strategies) to the control group (receiving standardized aerobic exercise) to see if the 9-grid model:

Reduces waist-hip ratio more effectively

Delays intervention plateau in body fat loss

Increases exercise adherence at 8 weeks

Participants will:

Undergo body measurements (weight, body mass index (BMI), body fat percentage, waist/hip circumference) at baseline, 4 weeks, and 8 weeks

Complete the Exercise Adherence Rating Scale (EARS) at 4 and 8 weeks

If in 9-grid group:

• Be classified into 1 of 9 grid zones every 2 weeks based on waist circumference risk + body fat status
• Receive zone-specific interventions (nutrition/exercise/behavioral guidance)

If in control group:

• Perform progressive aerobic exercise (40-90% heart rate reserve (HR) 3×/week
• Use heart rate monitors for intensity tracking

Inclusion Criteria:

1. Age & Status:

   • Full-time university students aged 18-36 years

2. Overweight/Obesity Diagnosis (per Chinese criteria):

   • Males: Body Mass Index (BMI) ≥24 kg/m² AND waist circumference ≥85 cm
   • Females: Body Mass Index (BMI) ≥24 kg/m² AND waist circumference ≥80 cm

3. Exercise Capacity:

   • Able to safely perform moderate-intensity exercise (confirmed by Physical Activity Readiness Questionnaire [PAR-Q], all items "No")

4. Tech Compliance:

   • Own smartphone with proficiency in health apps (e.g., WeChat Sport)

5. Informed Consent:

   • Signed written consent with commitment to complete 12-week intervention

Exclusion Criteria:

1. Metabolic Diseases:

   • Diagnosed diabetes, thyroid dysfunction, or history of cardiovascular disease

2. Exercise Contraindications:

   • Orthopedic/neurological conditions limiting exercise

3. Confounding Medications:

   • Use of weight/metabolism-affecting drugs in past 3 months

4. Special Physiological Status:

   • Pregnancy or lactation

5. Conflicting Participation:

   • Concurrent enrollment in other weight-management trials