['Obesity is a multifactorial disease and our understanding of this disease is still incomplete.', 'The aim of this investigation was to examine the associations between body fat percentage and physical fitness, diet and active/sedentary behaviors in female and male adolescents.', "A cross-sectional study was carried out on a sample of 1389 Spanish adolescents (706 boys and 683 girls) aged between 14 and 17years. Individual body fat percentage was measured by means of bioelectrical impedance analysis and participants' physical fitness was determined by measuring cardiorespiratory fitness (20-m shuttle run test), muscular strength (handgrip dynamometry), muscular endurance (curl-up and 90° push up repetition tests) and muscular flexibility (sit-and-reach test). Daily physical activity, sedentary time and diet were estimated using validated and self-reported questionnaires. The participants were divided into quartiles based on their body fat percentage.", 'Boys and girls included in Q3 and Q4 presented lower values for cardiorespiratory fitness than Q1 (P<0.05). Boys and girls included in Q4 also presented lower values for muscular endurance than Q1 (P<0.05). Only boys in Q4 presented lower levels of physical activity than Q1 (P<0.05). Physical activity, physical fitness and diet can explain 30% of the variance for body fat percentage in boys and 17% in girls.'] Is body fat percentage more associated with low physical fitness than with sedentarism and diet in male and female adolescents?