BACKGROUND: Obesity is a major problem in horses, unfortunately many times underrated by owners. Equine metabolic syndrome (EMS) is one of the obesity complications that can cause laminitis, hypertension, subfertility, and so on. Insulin dysregulation (ID) is the main feature of EMS that results from insulin resistance. OBJECTIVES: The aim of this study was to evaluate the role of feeding management in obesity and EMS occur-rence. METHODS: Five hundred seventy horses were evaluated in this study. They were divided into the groups based on age, gender, breed, exercise activity, and feeding type. Glucose and insulin were measured using an AutoAna-lyzer device and ELISA kit, respectively. RESULTS: Out of 570 horses, 2% had EMS while 14% were fat but obesity occurrence was higher in horses grazed in pasture (25%) compared to the horses that had not access to pasture (9%). CONCLUSIONS: Results showed that prevalence of EMS under different feeding strategies is significantly dif-ferent. For the prevention of this important welfare issue, feeding management and routine exercise are the best ways.