TBWL (Total Body Weight Loss)

Definition

The percentage of total body weight lost from baseline, reported as the primary endpoint in modern obesity trials. STEP-1 reported −14.9% TBWL on semaglutide 2.4 mg at 68 weeks; SURMOUNT-1 reported −20.9% TBWL on tirzepatide 15 mg at 72 weeks. TBWL is preferred over absolute kg change because it adjusts for starting body weight — a 15% loss in someone starting at 100 kg (15 kg) and 200 kg (30 kg) is clinically equivalent in metabolic terms.

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Definition curated by Weight Loss Rankings — sourced from FDA labels and peer-reviewed PubMed literature, never AI-generated summaries.

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