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Body Mass Index

Weight in kilograms divided by height in meters squared; the standard screening index for underweight, overweight, and obesity in adults.

Also: BMI, Quetelet index

Adult BMI categories: underweight <18.5, normal 18.5 to 24.9, overweight 25 to 29.9, obesity class I 30 to 34.9, class II 35 to 39.9, class III (morbid) >=40. BMI does not distinguish fat mass from lean mass and may misclassify muscular individuals or those with sarcopenic obesity. In children and adolescents, BMI is interpreted by age- and sex-specific percentiles.

How each textbook covers it

  • duyff-complete-food-and-nutrition-guide-5e

  • Krause and Mahan's Food and the Nutrition Care Process, 16th ed. — Chapter 5

    Adult BMI categories: underweight <18.5, normal 18.5 to 24.9, overweight 25 to 29.9, obesity class I 30 to 34.9, class II 35 to 39.9, class III (morbid) >=40. BMI does not distinguish fat mass from lean mass and may misclassify muscular individuals or those with sarcopenic obesity. In children and adolescents, BMI is interpreted by age- and sex-specific percentiles.

Related terms

Anthropometry, Obesity, Sarcopenia