7
1991 National Institutes of Health (NIH) Consensus
Guidelines for Bariatric Surgery Eligibility and the
Updated 2022 American Society for Metabolic and
Bariatric Surgery (ASMBS) Guidelines
Criteria 1991 NIH Guidelines 2022 ASMBS Guidelines
BMI threshold
(without
comorbidities)
BMI ≥40 kg/m² BMI ≥35 kg/m²
BMI threshold (with
at least one obesity-
related comorbidity)
BMI ≥35 kg/m² BMI ≥30 kg/m² with
metabolic disease
Age restrictions Generally, 18–60
years
No specific age limits;
assess physiological not
chronological age
Comorbidity examples Type 2 diabetes
mellitus (T2DM),
hypertension, sleep
apnea
Expanded list includes,
hypertension, dyslipidemia,
metabolic dysfunction-
associated steatotic liver
disease (MASLD)
Previous weight loss
attempts
Documented failure
of nonsurgical
weight loss efforts
Still recommended, but
not absolute requirement
in all cases
Psychological
evaluation
Required to rule out
contraindications
Required; emphasizes
interdisciplinary approach
Goal of surgery
Weight loss and
comorbidity
improvement
Health improvement,
including weight loss and
remission/improvement of
metabolic disease
