BMI (Body Mass Index)
Weight divided by height squared — the imperfect screening number that gates most weight-medication eligibility.
BMI is weight in kilograms divided by height in meters squared: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obesity. Its virtues are speed and population-level correlation with health risk; its famous blind spots are muscle (athletes read high), fat distribution (it can't see visceral fat), and ethnic variation in risk thresholds.
It persists because eligibility rules are written in it: Wegovy and Zepbound are indicated at BMI 30+, or 27+ with a weight-related condition, and insurance mirrors those cutoffs. Good clinicians treat BMI as a doorway rather than a diagnosis — waist circumference, labs, and history complete the picture — but knowing your number remains step one of any eligibility conversation, including our free consultations.
This glossary entry is general information, not medical advice, and is written to be consistent with FDA prescribing information and primary trial publications as of its last review. Always consult a licensed healthcare provider for personal medical decisions.
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