Weight Management

BMI: How to Calculate and Interpret

5 min readKilotaki Nutrition Editor
BMI: How to Calculate and Interpret

BMI = weight (kg) / height² (m). Practical general health indicator but misleading individually — doesn't distinguish fat from muscle. Athletes and muscular individuals may register 'overweight' despite having low body fat.

BMI Classification

<18.5: Underweight. 18.5-24.9: Normal. 25-29.9: Overweight. 30-34.9: Obese (Class I). 35-39.9: Obese (Class II). ≥40: Morbid obese. WHO standard.

  • BMI is just one tool
  • Use with waist circumference + body fat + muscle
  • Older adults (65+) BMI thresholds shift up (24-29 normal)

BMI Limitations

Doesn't show body composition. Ignores age, gender, ethnicity differences. Body shape (apple vs pear) matters but BMI doesn't track this.

Frequently Asked Questions

BMI normal but high waist circumference?

TOFI (Thin Outside Fat Inside) — high visceral fat. Use waist circumference + body fat test instead of BMI alone.

Scientific References

  1. WHO (2000) Obesity Classification.

This content is for general information only and does not replace medical advice. Consult your physician or a registered dietitian for personalized guidance.

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