Revising BMI Cut-Off Points for Overweight and Obesity in Male Athletes: An Analysis Based on Multivariable...

Area of Science:

• Sports Medicine
• Human Physiology
• Anthropometry

Background:

• Athletes typically have higher muscle mass and lower body fat (BF) than the general population.
• This can lead to misclassification of weight status using standard Body Mass Index (BMI) criteria.
• Existing World Health Organization (WHO) BMI cut-offs may not accurately reflect adiposity in athletic individuals.

Purpose of the Study:

• To evaluate the validity of WHO BMI cut-off points for overweight and obesity in young male athletes.
• To determine appropriate BMI thresholds for classifying weight status in this specific population.
• To compare BMI classification with body fat percentage (BF%) measured by dual-energy X-ray absorptiometry (DXA).

Main Methods:

• 622 young male athletes were categorized using WHO BMI criteria and subsequently by BF% via DXA.
• A multivariable model was used to develop a predictive equation for optimal BMI cut-offs.
• Agreement between classification systems was assessed using the kappa statistic (κ).

Main Results:

• WHO BMI classification showed weak agreement with BF% (κ = 0.169).
• Under WHO criteria, 23.8% were overweight and 3.7% obese, while by BF%, only 3.1% were overweight and 0.8% obese.
• New proposed BMI cut-offs (≥28.2 kg/m² for overweight, ≥33.7 kg/m² for obesity) demonstrated good agreement with BF% (κ = 0.522).

Conclusions:

• Current WHO BMI cut-offs are inadequate for assessing weight status in young male athletes.
• Newly proposed BMI cut-offs provide a more accurate classification of overweight and obesity in this group.
• Updated guidelines should incorporate these revised BMI thresholds for athletic populations.