Obesity is a significant health problem that is increasingly spreading among children and young people in recent years. In this paper, I will focus on obesity in preschool children and explain what it is, what are its causes, how we can prevent it, and how to help children who are already obese. One of the key factors in the prevention of obesity is a healthy diet. This includes eating a variety of nutrient-dense foods such as fruits, vegetables, whole grains, protein and healthy fats. It is also important to limit the intake of unhealthy foods that are rich in sugar, salt and saturated fat. Making the right food choices can help maintain a healthy weight and prevent obesity. Physical activity is another important aspect in the prevention of obesity. Preschool children should be encouraged to engage in regular physical activity that includes outdoor play, sports activities and age-appropriate exercises. Physical activity helps maintain healthy physical development, strengthens muscles and bones, and reduces the risk of obesity and various diseases. Parents, educators and public health organizations have a significant role in the prevention and treatment of obesity in preschool children. It is crucial to teach parents about the value of healthy eating and exercise, as well as to provide them with information about proper nutrition and to encourage the child's physical activity. A survey conducted among parents whose children attend DV Radost Jastrebarsko showed positive results regarding parents' knowledge and familiarity with regard to healthy eating and the importance of physical activity for their children. These results are encouraging because they indicate that parents recognize the importance of these factors and strive to implement healthy habits in their children's daily lives.