Introduction: In recent years, the use of nutritional supplements (NS) has increased significantly. The aim of this study was to investigate of the differences between using or not NS in the individuals going to the fitness center. Method: The research was conducted on 299 individuals doing sports in private centers. Survey data was collected from the participants who were divided into two groups according to NS usage. Within the scope of the survey, descriptive information of the participants, nutritional habits, nutrient consumption frequencies, 24-hour retrospective food consumption record, nutritional supplements and physical activity conditions of individuals were questioned and anthropometric (height, weight and body mass index (BMI) measurements were recorded. Results: 74 (24.7%) of the participants were using NS, whereas 225 (75.3%) were not using it. Among NS users, 30 (40.5%) of the participants were using protein powder, 17 (23%) were amino acid, 17 (23%) were creatine and 10 (13.5%) were L-carnitine. The sport age, body weight, height and BMI of the individuals using NS were significantly higher than those who were not using NS (p <0.05). According to our study, NS users were consuming meat, meat products and eggs significantly more frequently and sugar and prepared foods less frequently than non-users (p <0.05). Conclusion: In our study, it was observed that individuals going to the fitness center changed their lifestyle. It was observed that they used oral nutritional supplements as well as obtaining healthy nutritional habits. Before using NS, it is neccesary to change the nutritional habits and complete the essential needs for our body.