Medical glossary
BMI (Body Mass Index)
Weight in kilograms divided by height in metres squared.
Definition
BMI is a simple screening number: weight (kg) divided by height (m) squared. Under 18.5 is underweight, 18.5-24.9 healthy, 25-29.9 overweight, 30+ obese. It doesn't account for muscle mass, so athletes can have high BMIs without excess fat.
See also
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Glossary entries are general reference, not medical advice for any specific person.