Reassessing BMI thresholds for obesity: a population-based study in Turkish adults

Area of Science:

• Public Health
• Anthropometry
• Epidemiology

Background:

• Rising global obesity rates present significant public health challenges.
• Existing universal BMI cut-offs may not accurately assess obesity risk in diverse ethnic groups, including Turkish adults.

Purpose of the Study:

• To investigate the correlation between body mass index (BMI) and body fat percentage (BF%) in Turkish adults.
• To establish precise BMI cut-off points for obesity diagnosis tailored to the Turkish population.

Main Methods:

• Cross-sectional study involving 18-65 year olds in Kayseri, Turkey.
• Collected anthropometric data (height, weight, waist/hip circumference) and body composition via bioelectrical impedance analysis (BIA).
• Utilized Receiver Operating Characteristic (ROC) curve analysis to determine optimal BMI thresholds for obesity prediction based on BF%.

Main Results:

• A strong positive correlation was observed between BMI and BF% in both women (r=0.86) and men (r=0.68).
• Optimal BMI cut-off points for obesity were identified as 28.76 kg/m² (total), 28.80 kg/m² (women), and 28.76 kg/m² (men).
• Implementing these thresholds increased obesity prevalence from 27.7% to 33.6%, with excellent discriminative power (AUC=0.98 for women, 0.91 for men).

Conclusions:

• Current universal BMI cut-offs (≥30 kg/m²) likely underestimate obesity prevalence in the Turkish population.
• Developing national and gender-specific BMI thresholds is crucial for accurate obesity diagnosis.
• Tailored thresholds can enhance public health interventions for chronic non-communicable diseases.