The present study consists of evaluating, through anthropometric parameters, the different forms of malnutrition among school adolescents in the Sidi-Bel-Abbes city (north-west Algerian region). Our survey was carried out among 223 adolescents aged 16 to 18. The parameters of the students are age, weight and height. The calculation of the body mass index (BMI) was carried out for the entire population studied. At the same time, a questionnaire on food consumption was used. From these data, we determined the nutritional status of young adolescents.  The analysis of the results revealed an average weight (for both sexes) of 61.60 ± 12.87 kg (between 36 kg and 112 kg) and an average height of 1.70 ± 0.086 m (between 1.52 m and 1.96 m). The BMI values (according to the International Obesity Task Force “IOTF" references) indicate that most girls and boys have a normal build. About underweight, the obtained results indicate a high rate among boys (4.0%) compared to girls (2.2%). However, the obesity prevalence was almost twice as high among girls (3.14%) as among boys (1.79%). Being overweight during adolescence is a predictor of chronic disease risk at a young age.  The nutritional status evaluation of adolescents is a necessary step to maintain and improve their nutritional status and prevent metabolic diseases.