Objective. To verify difference of nutrition state and life habits among subgroups of grades sixth, seventh, ninth, and tenth of 10-16-age girls and adolescents, at private school in Cartagena city. Methods. Transversal study involving 467 girls and adolescents taking grade sixth, seventh, eighth, ninth and tenth at a private school. Informed consent is requested from directors of the school and parents, and information privacy was ensured. A pilot test was administered to 25 students of another school, bearing similar traits to those of the school selected for the study, in order to standardize the personnel. Results. The mean age was 13,6 (DE 1,7). 3% of girls presented obesity, and 9% overweight, more frequent in grades ninth and tenth. There are difference between the two groups regarding extra-curricular sports practice; for each one student of grade sixth and seventh practicing any sports, there are two ninth and tenth grade students who do not practice any sports [OR. 2.2 (1.5- 3.4)]. Students of grade sixth and seventh are under more risk of watching more than three hours of TV than grades ninth and tenth students [OR 1.5 (1,06 – 2, 29)]. Conclusion. In this study there is a higher risk of overweight in students taking upper grades, which is evidenced in their sedentary behavior.