BACKGROUND: The prevalence of metabolically healthy obese (MHO) subjects among morbidly obese subjects is poorly described.

AIM: To describe the prevalence of metabolically healthy subjects in a group of morbidly obese referred for bariatric surgery.

METHODS: Descriptive cross-sectional study, 1209 subjects (825 women/384 men) mean body mass index (BMI) of 45.6 (range: 35-72.6) kg/m2 and mean age of 42.9 (range: 18-72) years were included. Metabolically unhealthy obese subjects had at least two metabolic risk factors: systolic blood pressure >130 mmHg or diastolic blood pressure >85 mmHg or use of antihypertensive medication, diagnosed diabetes with a HbA1c >6.5% (>48 mmol/mol) or use of antidiabetic medication, high plasma triglycerides or low plasma high-density lipoprotein, or use of lipid-lowering medication. MHO subjects had one or no metabolic risk factors.

RESULTS: Thirty-four percent (413/1209) were characterized as MHO subjects. The MHO stage was characterized by female sex, younger age, and lower neck and waist circumferences. The odds ratio of metabolic unhealthy was 1.12 (1.07-1.17, P < 0.001) and 1.02 (1.01-1.04, P < 0002) for every 1 cm increase in neck and waist circumferences, respectively, and 0.94 (0.91-0.97, P < 0.001) for every 1 U increase in BMI and 1.04 (1.03-1.05, P < 0.001) for every 1 year increase in age.

CONCLUSIONS: Among severely obese subjects, 34% were classified as having a metabolically healthy state, which was more likely to occur in females, younger individuals and was associated with a lower neck and waist circumferences, younger age, and higher BMI. Whether a group of MHO subjects will remain healthy lifelong is unknown.