Abstract Objective: To indicate neck circumference (NC) cutoff points to identify excess weight at different stages of somatic maturation and evaluate the association between NC and body mass index (BMI). Methods: Cross-sectional study with 1715 adolescents. BMI was classified according to the World Health Organization (WHO) criteria. Somatic maturation was obtained through the peak growth velocity (PGV). To define the cutoff points, curves of the receiver operating characteristic (ROC) model were constructed. The agreement between the anthropometric evaluation instruments was analyzed. The association between the variables was verified. Results: Of the girls, 93 were in the pre-PGV stage, 266 in the PGV stage, and 481 in the post-PGV stage. Of the boys, 264 were in the pre-PGV stage, 334 in the PGV stage, and 277 in the post-PGV stage. For the pre-PGV group, the cutoff point was 28 cm for females and 29 cm for males; for the group during PGV, the cutoff points were 30 cm for females and 33 cm for males; in the post-PGV group the cutoff values were 32 cm in females and 35 cm in males. The prevalence of excess weight was higher in the pre-PGV stage in males and in the PGV stage in females. The correlation coefficients were higher in the pre-PGV and PGV stages. Conclusion: The cutoff points for NC found in this study showed good sensitivity and specificity to identify excess weight in Brazilian adolescents and can be used as a reference in epidemiological studies.

RESUMO Objetivo: Identificar a prevalência de excesso de peso em adolescentes de acordo com diferentes critérios de classificação de obesidade e estágios de maturação somática. Métodos: Estudo transversal em dez escolas de um município da região Sul do Brasil, com 1.715 adolescentes. Dados de estatura, peso, circunferência da cintura e circunferência do pescoço (CP) foram coletados. O índice de massa corpórea (IMC) foi classificado com os critérios da Organização Mundial da Saúde (OMS) e do Centers for Disease Control and Prevention, e a razão cintura-estatura (RCE) foi classificada de acordo com pontos de corte brasileiros e europeus. A maturação somática foi obtida por meio do pico de velocidade do crescimento (PVC). Os dados de prevalência foram comparados entre os sexos e os estágios maturacionais; verificou-se a concordância entre os diferentes critérios. Resultados: A prevalência do excesso de peso foi elevada em ambos os sexos. Com o critério da OMS, a prevalência foi de 34,5% nos meninos e 29,3% nas meninas. Para a RCE, a prevalência foi de 28,4% nos meninos e 23,7% nas meninas. A CP rastreou 13,8% de excesso de peso nos meninos e 15,8% nas meninas. A prevalência de excesso de peso foi mais elevada em adolescentes antes da maturação somática completa. Conclusões: A prevalência do excesso de peso foi elevada entre os adolescentes. Os meninos apresentaram maior percentual de excesso de peso, exceto na variável CP. Adolescentes antes da maturação somática apresentaram maior prevalência de sobrepeso. A CP tem menor capacidade de rastrear adolescentes obesos.

ABSTRACT Objective: To identify the prevalence of overweight in adolescents according to different classification criteria for obesity and somatic maturation stages. Methods: Cross-sectional study in 10 schools in a city from Southern Brazil, with 1715 adolescents. Height, weight, waist circumference, and neck circumference (NC) data were collected. Body Mass Index was classified according to World Health Organization (WHO) and Centers for Disease Control and Prevention criteria, and the waist-to-height ratio (WHtR) was classified according to Brazilian and European cut-off points. Somatic maturation was obtained through the Peak Height Velocity. The prevalence data were compared between sex and stages of somatic maturation; the concordance between different criteria was verified. Results: The prevalence of overweight was high in both sexes; WHO criteria showed that 34.5% of boys and 29.3% of girls were overweight. For the WHtR, the prevalence was 28.4% in boys and 23.7% in girls. NC classified 13.8% of boys and 15.8% of girls as being overweight. The prevalence of overweight was higher in adolescents before complete somatic maturation. Conclusions: The prevalence of overweight was high among adolescents. The boys presented higher frequency of overweight, except if NC was used to classify them. Adolescents before somatic maturation had a higher prevalence of overweight. NC showed a lower ability to track obese adolescents.

RESUMO Objetivo: Verificar a efetividade de intervenções educacionais baseadas na orientação sobre atividade física e nutrição em escolares. Fonte de dados: Foi realizada busca sistemática em quatro bancos e bases de dados eletrônicos, com artigos publicados entre outubro de 2007 e janeiro de 2017 que abordaram a realização de intervenções educacionais com ênfase em educação nutricional e atividade física ou exercício físico em escolares com idades entre 10 e 19 anos. Síntese dos dados: Foram selecionados 12 artigos para esta revisão. Desses estudos, quatro incluíram a intervenção educacional; quatro associaram intervenções educacionais à inclusão de alimentos saudáveis e atividade física; dois estudos relacionaram as orientações e a atividade física; e, por fim, dois ligaram as orientações com o consumo de alimentos saudáveis. Conclusões: As intervenções baseadas na orientação de atividade física e/ou nutrição foram eficientes, com resultados superiores nos estudos que associaram a prática de atividade física à orientação. Entretanto, observou-se a necessidade da realização de novos estudos que abordem as intervenções educacionais em escolares.

ABSTRACT Objective: To verify the effectiveness of educational interventions based on guidance on physical activity and nutrition in schoolchildren. Data sources: A systematic search was carried out in four electronic databases containing articles published between October 2007 and January 2017 and addressing educational interventions with emphasis on both nutritional education and physical activity in schoolchildren and adolescents aged 10 to 19 years. Data synthesis: Twelve articles were selected for this review, of which four included only educational interventions; four made and association between educational interventions, inclusion of healthy foods and physical activity; two made a relation between guidelines and physical activity; and finally, two associated guidelines with consumption of healthy foods. Conclusions: Interventions based on physical activity and/or nutrition counseling were efficient and showed superior results in studies that associated the practice of physical activity with counseling. However, the need for new studies on educational interventions among schoolchildren and adolescents was made evident.