The period of preschool age is crucial for the formation of healthy lifestyle habits. At this stage, children adopt patterns of behavior and habits that follow them for the rest of their lives. The modern way of life, characterized by sedentary habits and unhealthy diet, contributes to the increase in the number of obese children, which is becoming an increasing problem. Childhood obesity has profound consequences for physical health and brings psychological consequences as well. Increased mortality in latter life is also associated with childhood-onset obesity. Environmental factors stand out among the main causes, including social and family dynamics, which promote a sedentary lifestyle. The availability and popularity of fast, calorie- and nutritionally poor foods make it even more difficult to maintain a healthy body weight. At the same time, physical activity is reduced to a minimum due to the problems of technology and screens, on which children spend most of their free time. This paper deals with the study of the connection between lifestyle and nutritional status of preschool children, emphasizing the importance of obesity prevention from an early age. By promoting proper nutrition, encouraging sufficient physical activity and reducing the time spent in front of screens, a positive effect on the child's health and body weight can be achieved. The role of preschool institutions is also crucial in creating a stimulating environment that supports a healthy lifestyle, which ultimately contributes to reducing the risk of obesity and promoting health in later life. The importance of play as children's most important activity is emphasized, and the paper provides examples of games that can be used to promote physical activity.