343 Rev Chil Nutr 2019; 46(3): 343-351 Artículo de Actualización / Review Article Este trabajo fue recibido el 26 de marzo de 2018. Aceptado con modifcaciones: 22 de octubre de 2018. Aceptado para ser publicado: 28 de diciembre de 2018. http://dx.doi.org/ 10.4067/S0717-75182019000300343 ABSTRACT The object of the present study was to carry out a literature review to analyze the infuence of physical activity and dietary behavior on body mass index in school-age children and adolescents. A search was carried out using the PubMed and LILACS databases, in which 1,412 articles were found. After application of inclusion and exclusion criteria, 17 stu- dies were selected for qualitative analysis. Overweight and obesity were related with incorrect dietary habits (skipping breakfast, consumption of foods with high fat contents and high-sugar soft drinks), low levels of physical activity and long hours devoted to sedentary activities (playing video games or watching TV) were also related. Keywords: Adolescents, Body mass index, Children, Dietary behaviour, Physical activity. RESUMEN El objetivo de este estudio fue analizar, mediante una revi- sión de la literatura, la infuencia de la práctica de actividad física y del comportamiento dietético sobre el índice de masa corporal de niños y adolescentes en fase escolar. Se realizó una búsqueda en las bases PubMed y LILACS. Se encontraron 1.412 artículos. Tras la aplicación de los criterios de inclusión y exclusión fueron seleccionados 17 estudios para realizar un análisis cualitativo. El sobrepeso y la obesidad están relacionadas a una alimentación in- adecuada (saltar el desayuno, consumo de alimentos con alto contenido de grasa y de bebidas azucaradas), niveles bajos de actividad física y longas horas realizando actividad sedentaria (jugando video-juegos o visualizando la TV). Palabras clave: Actividad física, Adolescentes, Comporta- miento dietético, Índice de masa corporal, Niños. INTRODUCTION The incidence of overweight and/or obesity in children and adolescents has increased signifcantly, principally in developed countries and certain segments of developing countries 1 . In Latin America, it is estimated that between 42,4 and 51,8 million children and adolescents suffer from excess body mass, representing 20-25% of this population 2 . In European countries, the prevalence of infant and juvenile The infuence of physical activity and eating behaviour on body mass index in children and adolescents: A review the literature Infuencia de la práctica de la actividad física y del comportamiento dietético en el índice de masa corporal de niños y adolescentes: Revisión de literatura Francisco Macedo Uchôa 1 , Romário Pinheiro Lustosa 2 , Joaquim Cintra Andrade 3 , Welton Nogueira Godinho 4 , Ágata Marques Aranha 5 , Naira F. Deana 6 , Nilton Alves 7,8 . 1.Doctorate student in Sport Sciences - University of Trás-os-Montes and Alto Douro, Vila Real, Portugal. 2. State University of Ceará, Fortaleza, Brazil. 3. Federal University of Santa Catarina, Florianópolis, Brazil. 4. Higher Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Brazil. 5. Departament of Desporto, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal. 6.Center for Research in Epidemiology, Economics and Oral Public Health(CIEESPO), Faculty of Dentistry, Universidad de La Frontera, Temuco, Chile. 7.Center of Research in Applied Morphology. Faculty of Dentistry Universidad de La Frontera, Temuco, Chile. 8. Center of Excellence in Surgical and Morphological Research (CEMyQ), Faculty of Medicine, Universidad de La Frontera, Temuco, Chile. Corresponding author: Nilton Alves Av. Center of Research in Applied Morphology. Faculty of Dentistry Francisco Salazar, 1145, Casilla 54-D, Temuco, Chile. E-mail: nilton.alves@ufrontera.cl obesity is over 20% 3 , while the fgure is lower in Asian countries, estimated to be between 5% and 10% 4 . Obesity not only leads to an increase in the incidence of diseases, such as diabetes, hypertension, cerebrovascular accidents and cancer, but it can also cause psychological problems, such as a reduction in self-esteem and increasing depression in children and adolescents subject to strong socio-cultural pressure to possess a thin body 5 . Overweight children and adolescents are more likely to follow unhealthy diets to try to control their weight compared to those whose weight is normal 6 ; in particular, overweight girls present a higher risk of developing eating disorders due to the socio-cultural pressure to be thin 7 . Dietary behaviour is determined by demographic,