Association of physical activity, central adiposity, and fast-food consumption with 2-hour plasma glucose in adolescent girls at a boarding school in East Java

Introduction
Type 2 diabetes mellitus (T2DM) is increasingly reported among adolescents and is associated with modifiable factors such as central obesity, physical inactivity, and frequent intake of fast food. Boarding schools offer a structured environment to assess these behaviours.

Aim of the study
To examine the correlation between physical activity, central adiposity, fast-food consumption, and 2-hour plasma glucose (2-hPG) in adolescent girls at a boarding school.

Material and methods
A cross-sectional study was conducted among 127 adolescent girls in East Java. Physical activity was assessed using the Physical Activity Questionnaire for Adolescents. Adiposity was measured using body mass index (BMI) and waist circumference. Fast-food consumption frequency was recorded through a structured questionnaire. Blood glucose was measured using a 2-hPG test after oral glucose intake. Urine dipstick screening was also performed.

Results
Most participants had normal BMI, though 11.8% were overweight or obese. In total, 12.6% showed impaired glucose tolerance (IGT, 2-hPG 140–199 mg/dl) and had significantly larger waist circumference (p = 0.03). Waist circumference showed a non-significant correlation with 2-hPG (r = 0.041; p = 0.643); also, BMI showed no significant association with 2-hPG (r = 0.032; p = 0.723). Significant correlations were found between physical activity and 2-hPG (r = 0.205; p = 0.021), and between fast-food intake and BMI (r = –0.208; p = 0.020), although fast-food intake was not associated with 2-hPG (r = 0.038; p = 0.674).

Conclusions
Early indicators of T2DM risk were identified. Although most associations were modest, increased waist circumference and reduced physical activity were associated with IGT, supporting the need for school-based lifestyle interventions.