Assessment of obesity beyond body mass index to determine benefit of treatment

•  Weight or weight loss per se may not indicate health status or health benefit. •  There is no gold standard for assessing which patients would benefit most from weight-loss interventions. •  The King's Criteria is one of several recently proposed obesity classification systems.

•  The King's Criteria can capture health problems related to obesity and health benefits after weight loss. •  The King's Criteria is a reproducible scoring system. •  Using the King's Criteria may help shift the focus of patients and clinicians from weight loss to health gain.

Body mass index (BMI) alone does not reflect health status in individuals. The King's Obesity Staging Criteria is a clinical tool for the assessment of patients with complex obesity. We assessed the performance of a modified version of the King's Criteria by scoring 144 obese patients before and 1 year after bariatric surgery. We also evaluated inter-observer variability by having 11 clinicians score the same 12 patients. The King's Obesity Staging Criteria comprise nine health domains: Airways, Body mass index, Cardiovascular disease, Diabetes, Economic complications, Functional limitations, Gonadal axis, Health status (perceived), and body Image. For each domain, a person's health is assigned a score of 0 ('normal health'), 1 ('at risk'), 2 ('established disease') or 3 ('advanced disease'). The patient's mean BMI decreased from 48 ± 7 to 37 ± 7 kg m(-2) post surgery. Before surgery, 84% of patients were either in stage 2 ('established disease') or stage 3 ('advanced disease') for one or more domains other than BMI. The modified King's Criteria showed significant health improvements after surgery, with a higher proportion of patients scored in stage 0 ('normal health') within each health domain (P < 0.001 for all). Observers assigned the same score in >75% of cases for all domains except Health status perceived (71%) and body Image (65%). In conclusion the King's Criteria captured morbidity in obese patients and health gains after weight loss. Different clinicians mostly assigned similar scores. The King's Criteria is a clinical tool that may help shift the focus of patients and clinicians towards improving health and not only losing weight.

NCT01112228 (http://www.clinicaltrials.gov).