Healthy lifestyle habits that include daily physical activity and a proper diet have a positiveeffect on the physical, motor and mental development of every person, including children. Also, such habits can prevent high body mass index results and the onset of various diseases, such as various eating disorders (anemia, bulimia, compulsive overeating, etc.). This research explains the concept of nutrition and the factors that can negatively affect the occurrence of the disease. The aim of this thesis was to determine the current state of nutrition and the current state of motor skills of preschool children and their mutual correlation. The research was conducted using 8 motor tests on 13 respondents aged 5 to 7 years. Some research participants have been involved in the training process of kyokushin karate for a long time, while some are just beginners. During the research, the method of descriptive statistics and regression analysis was used for data processing. The obtained results showed a negative correlation between a high body mass index and tests of repetitive (torso bending) and explosive strength (long jump from a standing position) measured in children who practice kyokushin karate. Specifically, children with a higher BMI jumped less far and did fewer sit-ups than children with a lower body mass index. Also, the results of measuring the level of nutrition showed that more than half, or almost the entire group, was overweight or obese (85%). Every day we encounter this trend of increasing the number of obese and overweight children, so it is important to emphasize proper nutrition and physical activity. Parents and educators should be role models for children and help them create healthy lifestyle habits. Also, children should be given the opportunity to play, which is the main activity for children, where they try out various motor skills.