Supervised machine learning algorithms for the classification of obesity levels using anthropometric indices derived
Rodrigo Yáñez-Sepúlveda1, Aldo Vásquez-Bonilla2, Rodrigo Olivares3
1Faculty Education and Social Sciences, Universidad Andres Bello, Viña del Mar, Chile.
Scientific Reports
|August 21, 2025
Summary
Machine learning accurately classifies obesity using body composition data. Random forest models, utilizing fat mass index and BMI, offer superior performance for public health screening.
Area of Science:
- Biomedical Engineering
- Data Science
- Public Health
Background:
- Accurate obesity classification is crucial for public health and clinical decisions.
- Traditional measures like Body Mass Index (BMI) have limitations in distinguishing fat from lean mass.
- Bioelectrical Impedance Analysis (BIA) offers detailed body composition metrics.
Purpose of the Study:
- To evaluate and compare supervised machine learning algorithms for obesity classification.
- To utilize anthropometric indices from BIA for improved obesity assessment.
- To identify key features influencing obesity classification.
Main Methods:
- A cross-sectional study of 5372 adults using BIA-derived anthropometric data.
- Trained and evaluated six machine learning models: Random Forest, Gradient Boosting, KNN, Logistic Regression, SVM, and Decision Tree.
- Assessed model performance using accuracy, F1-score, AUC-ROC, and SHapley Additive exPlanations (SHAP).
Main Results:
- Random Forest achieved the highest accuracy (84.2%), F1-score (83.7%), and AUC-ROC (0.947).
- Fat Mass Index (FMI), Fat-Free Mass Index (FFMI), and BMI were the most influential predictors.
- Sex showed minimal impact on predictive performance.
Conclusions:
- Supervised machine learning, especially Random Forest, demonstrates high accuracy and interpretability in classifying obesity.
- BIA-derived anthropometric data enhances obesity classification beyond traditional BMI.
- These models hold significant potential for improving obesity screening in clinical and community settings.


