Abstract Background Obesity was once though as an indispensable component of metabolic syndrome. Therefore, there a lot of definitions of metabolic syndrome with only few not including obesity as a criterion. The necessity of the obesity criterion in the metabolic health assessment is being questioned, as similar metabolic disturbances can occur in normal weight individuals. This relatively new concept is often referred as lean metabolic syndrome. Data on long term prognosis is scarce. Purpose To evaluate association between metabolic health and long-term prognosis. Methods Lipidogram studies were carried out in Poland in 2004, 2006 and 2015 in the population representative for patients in primary care setting. Patients were recruited in all 16 administrative regions in Poland and physicians were proportionally to the number of inhabitants in a given administrative region. Each patient was given a questionnaire on chronic diseases, treatment and lifestyle. Questionnaire was administered by physician. The diagnosis of metabolic syndrome was based on the presence of at least two of the following: 1) systolic blood pressure (SBP) ≥130 mmHg or diastolic blood pressure (DBP) ≥85 mmHg, 2) triglycerides (TG) >150 mg/dl, 3) high-density lipoprotein cholesterol (HDL-C) <40 mg/dl men and <50 mg/dl in women, 4) total cholesterol (TC) >200 mg/dl, and 5) fasting glucose (FBG) >100 mg/dl. Basing on those criteria and BMI with a cut off value of 25 kg/m2, patients were divided into four categories: healthy slim, metabolically healthy overweight/obese, lean metabolic syndrome and overweight/obese metabolic syndrome. The median follow up was 5570. this analysis data were censored at 3650 days. Results The median age of the study participants was 56.4 years. 7901 (16.7%) fell into category healthy slim, 14607 (30.8%) were classified as metabolically healthy overweight/obese, 3827 (8.1%) fulfilled criteria for lean metabolic syndrome whilst the remaining 21063 (44.4%) patients were diagnosed with overweight/obese metabolic syndrome. There were 4065 deaths during 10 years follow-up. Patients with lean metabolic syndrome had similar risk as patients with overweight/obese metabolic syndrome (HR=1.33, 95% CI: 1.17–1.52, p<0.001 and HR=1.32, 95% CI: 1.20–1.45, p<0.001). Metabolically heathy overweight/obese patients had only slightly higher risk of dying than healthy slim patients but this difference was less pronounced (HR=1.11, 95% CI: 1.08–1.23, p=0.03). Conclusions Lean metabolic syndrome confers similar risk as metabolic syndrome in overweigh/obese patients. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): The present study was funded by an unrestricted educational grant from Valeant. As a supporter of the study, Valeant played no role in the study design, data analysis, data interpretation, or writing of the report. The present study was also supported by Silesian Analytical Laboratories (SLA, Katowice, Poland).