The study assessed the nutritional habits and preferences, the intake of water from food products and beverages, the intake of energy and self-assessment of physical activity of a 100 children leaving primary school. The body composition was assessed by the bio-impedance method. The results were interpreted with the use of the centile charts for the children of Lodz, indicating body mass deficiency in 6% of the subjects, overweight in 11% and obesity in 16%. The analysis of nutrition and nutritional preferences revealed numerous irregularities. The study did not demonstrate a statistically significant correlation between the body composition, the dietary energy and water intake and the physical activity declared by the subjects (p<0.05).