OBJETIVO: Delinear sistema de classificação, composto de curva de referência e valores críticos, baseado na distribuição do índice de massa corporal (IMC) em população de referência nacional e destinado à avaliação do estado nutricional de crianças e adolescentes brasileiros. MÉTODO: Dados de 13.279 homens e 12.823 mulheres com idade de 2 a 19 anos, extraídos da Pesquisa Nacional Nutrição e Saúde (1989), foram utilizados para construir a curva de referência. Utilizou-se o método LMS para o cálculo dos parâmetros da curva do IMC e a função polinomial para modelar esses parâmetros ao longo das idades. Os valores críticos para classificação do estado nutricional em déficit de peso, excesso de peso e obesidade foram expressos de acordo com centis e valores do IMC equivalentes a 17,5, 25 e 30 kg/m² , respectivamente, aos 20 anos. RESULTADOS: Os valores dos parâmetros L, M e S foram tabulados em intervalos semestrais para cada sexo. A partir desses valores, foi construído o gráfico com nove centis da distribuição de referência do IMC. Foram apresentados os valores críticos equivalentes aos valores de 17,5, 25 e 30 kg/m² no início da idade adulta. CONCLUSÃO: O sistema classificatório apresentado pode ser utilizado em avaliações clínicas e epidemiológicas, é similar metodologicamente à grande parte das curvas nacionais já apresentadas e oferece, ainda, a definição de baixo peso.

OBJECTIVE: To delineate a classification system, comprising reference curves and cutoff points, based on the distribution of body mass index (BMI) across a national reference population and designed for the assessment of the nutritional status of Brazilian children and adolescents. METHODS: Data from 13,279 males and 12,823 females aged from 2 to 19 years, extracted from the National Nutrition and Health Survey dataset (1989), were used to construct a reference curve. The LMS method was employed to calculate the BMI curve parameters and polynomial functions were used to model these parameters against age. The cutoff values for classifying nutritional status as underweight, overweight and obese were expressed as centiles and BMI values equivalent to 17.5, 25 and 30 kg/m² at 20 years, respectively. RESULTS: Values for the L, M and S parameters were tabulated at 6-month intervals for each sex. Using these values, a graph was plotted with nine BMI distribution reference centiles. Cutoff values were presented that are equivalent to BMIs of 17.5, 25 and 30 kg/m² at the start of adulthood. CONCLUSIONS: The classification system presented here can be used for clinical and epidemiological assessments, it is methodologically similar to the majority of national curves that have been presented to date and, furthermore, it offers a definition of underweight.

A landmark review of studies published prior to 1989 on socioeconomic status (SES) and obesity supported the view that obesity in the developing world would be essentially a disease of the socioeconomic elite. The present review, on studies conducted in adult populations from developing countries, published between 1989 and 2003, shows a different scenario for the relationship between SES and obesity. Although more studies are necessary to clarify the exact nature of this relationship, particularly among men, three main conclusions emerge from the studies reviewed: 1. Obesity in the developing world can no longer be considered solely a disease of groups with higher SES. 2. The burden of obesity in each developing country tends to shift towards the groups with lower SES as the country's gross national product (GNP) increases. 3. The shift of obesity towards women with low SES apparently occurs at an earlier stage of economic development than it does for men. The crossover to higher rates of obesity among women of low SES is found at a GNP per capita of about US$ 2500, the mid-point value for lower-middle-income economies. The results of this review reinforce the urgent need to: include obesity prevention as a relevant topic on the public health agenda in developing countries; improve the access of all social classes in these countries to reliable information on the determinants and consequences of obesity; and design and implement consistent public actions on the physical, economic, and sociocultural environment that make healthier choices concerning diet and physical activity feasible for all. A significant step in this direction was taken with the approval of the Global Strategy on Diet, Physical Activity and Health by the World Health Assembly in May 2004.

Un análisis que marcó un hito sobre los estudios publicados antes de 1989 acerca de la situación socioeconómica (SSE) y la obesidad respaldó la idea de que en el mundo en desarrollo esa patología era fundamentalmente una enfermedad de la élite socioeconómica. El presente análisis, centrado en estudios realizados en poblaciones adultas de los países en desarrollo y publicados entre 1989 y 2003, muestra un panorama distinto de la relación entre la SSE y la obesidad. Aunque se necesitan nuevos trabajos para esclarecer la naturaleza exacta de esa relación, en particular entre los hombres, de los estudios examinados se desprenden tres conclusiones principales: 1. Ya no es posible considerar que en el mundo en desarrollo la obesidad sea exclusivamente una enfermedad de los grupos con mejor SSE. 2. La carga de obesidad de cada país en desarrollo tiende a desplazarse hacia los grupos con SSE inferiores a medida que aumenta el producto nacional bruto (PNB). 3. El desplazamiento de la obesidad hacia las mujeres con menor SSE ocurre aparentemente antes que en los hombres conforme avanza el desarrollo económico. El punto de transición a las tasas mayores de obesidad entre las mujeres de baja SSE se encuentra a un PNB per cápita de aproximadamente US$ 2500, el punto medio de las economías de ingresos bajos-medios. Los resultados de este análisis subrayan la necesidad urgente de: incluir la prevención de la obesidad como tema destacado en la agenda de salud pública en los países en desarrollo; mejorar el acceso de todas las clases sociales de esos países a información fidedigna sobre los factores determinantes y las consecuencias de la obesidad; y concebir y aplicar en los entornos físico, económico y sociocultural medidas de salud pública coherentes que aseguren que todo el mundo pueda elegir las opciones más saludables en materia de régimen alimentario y actividad física. Un importante paso en ese sentido es el que dio la Asamblea Mundial de la Salud en mayo de 2004 al aprobar la Estrategia Mundial sobre Régimen Alimentario, Actividad Física y Salud.

Une revue de référence des études publiées avant 1989 sur le thème statut socio-économique (SSE) et obésité a soutenu le point de vue que, dans le monde en développement, l'obésité était essentiellement une maladie de l'élite socio-économique. La présente revue, qui concerne des études menées chez des populations adultes de pays en développement, publiées entre 1989 et 2003, révèle un schéma différent pour la relation entre SSE et obésité. Bien que des études supplémentaires soient nécessaires pour clarifier la nature exacte de cette relation, en particulier chez les hommes, trois conclusions principales ressortent des études examinées : 1. l'obésité dans le monde en développement ne peut plus être considérée uniquement comme une maladie des groupes de statut socio-économique élevé, 2. dans chaque pays en développement, la charge de l'obésité tend à se transposer aux groupes de faible SSE à mesure que le produit national brut (PNB) du pays augmente, 3. la transposition de l'obésité aux femmes de faible SSE se produit apparemment à un stade plus précoce du développement économique que pour les hommes. La transition vers des taux élevés d'obésité parmi les femmes de bas SSE s'observe pour un PNB par tête d'environ US $ 2500, correspondant à la valeur moyenne du PNB pour les économies à revenus faibles et moyens. Les résultats de cette revue renforcent encore la nécessité pressante d'inscrire la prévention de l'obésité parmi les questions de santé publique importantes dans les pays en développement, d'améliorer l'accès de toutes les classes sociales de ces pays à une information fiable sur les déterminants et les conséquences de l'obésité, et de concevoir et de mettre en œuvre des interventions publiques cohérentes sur l'environnement physique, économique et socioculturel, permettant à tous des choix plus sains en matière de régime alimentaire et d'activité physique. Une étape importante dans cette direction a été franchie avec l'approbation de la stratégie mondiale pour l'alimentation, l'activité physique et la santé par l'Assemblée mondiale de la santé, en mai 2004.

OBJECTIVES: To describe the prevalence, frequency, type, motivation for, and demographic and socioeconomic distribution of leisure-time physical activity (LTPA) among adults in Brazil. METHODS: The data source for our study was the Brazilian Living Standards Measurement Survey (LSMS) (Pesquisa sobre Padrões de Vida), which was conducted in 1996 and 1997. This survey studied a multistage stratified probabilistic sample of 4 893 households, which included 11 033 persons who were 20 years of age or older. The surveyed households were selected in the two most populous Brazilian regions, the Northeast and the Southeast, where in total 70% of all Brazilians live. The selected persons responded to a series of questions concerning their leisure-time physical activities. RESULTS: Only 13% of the Brazilians surveyed reported performing at least a minimum of 30 minutes of LTPA on one or more days of the week, and only 3.3% reported doing the recommended minimum of 30 minutes on 5 or more days of the week. In younger age groups, men were more active than were women. However, this difference sharply decreased with increasing age, and by the age range of 40 to 45 years the prevalence of LTPA was similarly low in both genders. Men reported engaging in more team sports, and women reported more walking/jogging activities, but walking/jogging was relatively more common in both genders when physical activity was performed on 5 or more days of the week. Recreation was by far the leading reason given by men to engage in LTPA, while recreation, health concerns, and even esthetic concerns were all relevant for women. In both genders, health concerns tended to be relatively more important for those exercising more days of the week. Also in both genders, increasing age was associated with more frequent LTPA, more walking/jogging than team sports, and more health concerns reasons than reasons related to recreation. Among both men and women there was a strong association between LTPA and socioeconomic status, measured either by income or schooling, independent of age, region, and urban or rural place of residence. CONCLUSIONS: The prevalence of adult LTPA in Brazil was much lower than the levels that have been reported for developed countries. However, the demographic and social distribution of LTPA in Brazil followed a pattern similar to the one usually observed in developed nations, where men tend to be more active than women, increasing age limits LTPA, and higher socioeconomic status is associated with more LTPA. Our data will provide a baseline to evaluate the impact on LTPA of "Agita Brasil" ("Move, Brazil"), an initiative to encourage physical activity that was implemented in the country after 1997.

OBJETIVOS: Describir la prevalencia, frecuencia, tipo, motivación y distribución demográfica y socioeconómica de la actividad física en horas libres (AFHL) entre adultos en el Brasil. MÉTODOS: La fuente de datos para nuestro estudio fue la Encuesta para la Medición del Nivel de Vida (EMNV) en el Brasil, que se llevó a cabo en 1996 y 1997. Mediante esta encuesta se estudió una muestra probabilística multietápica y estratificada de 4 893 hogares que abarcó a 11 033 personas de 20 años de edad o mayores. Los hogares encuestados se seleccionaron en la dos regiones más pobladas del Brasil, el Noroeste y el Sureste, donde viven 70% de todos los habitantes del Brasil. Las personas seleccionadas contestaron una serie de preguntas acerca de sus actividades físicas en horas libres. RESULTADOS: Sólo 13% de los brasileños encuestados indicaron que hacían un mínimo de 30 minutos de AFHL un día de la semana o más, y únicamente 3,3% indicó que lo hacía como mínimo 30 minutos durante 5 días de la semana o más, que es la cantidad recomendada. Entre las personas más jóvenes se encontró que los hombres eran más activos que las mujeres. No obstante, esta diferencia descendió notablemente a medida que aumentó la edad, de tal manera que en el grupo de 40 a 45 años la prevalencia de AFHL era igualmente baja en ambos sexos. Los hombres indicaron que participaban en deportes en equipo, mientras que las mujeres dijeron que participaban en actividades tales como caminar o trotar (jogging), pero estas últimas fueron las actividades más comunes en ambos sexos en aquellos casos en que la actividad física se practicaba 5 días a la semana o más. El recreo fue, con mucho, la razón que los hombres citaron con mayor frecuencia para explicar por qué practicaban AFHL, mientras que el recreo, la salud y hasta razones estéticas fueron citados como aspectos importantes por las mujeres. En ambos sexos la salud fue un motivo más importante entre las personas que practicaban alguna actividad física durante un mayor número de días a la semana. También se observó en ambos sexos un aumento de la frecuencia de AFHL conforme aumentaba la edad, con una mayor tendencia a caminar o a trotar que a practicar deportes y con una mayor preocupación por la salud que por el recreo. Tanto entre los hombres como entre las mujeres se observó una fuerte asociación entre la AFHL y el estado socioeconómico, medido ya sea en términos de ingresos o de escolaridad, independientemente de la edad, la religión, o la residencia en una zona urbana o rural. CONCLUSIONES: La prevalencia de AFHL en la población adulta del Brasil fue mucho más baja que la notificada en países en desarrollo. Sin embargo, la distribución demográfica y social de la AFHL en el Brasil tuvo un patrón similar al observado habitualmente en países desarrollados, donde los hombres tienden a ser más activos que las mujeres, la mayor edad limita la AFHL, y un mayor nivel socioeconómico se asocia con más AFHL. Nuestros datos servirán de base para evaluar los efectos de la AFHL de "Agita Brasil" ("Muévete, Brasil"), iniciativa en pro de la actividad física que se puso en marcha en el país después de 1997.

A partir de inquéritos nutricionais probabilisticos realizados nas três últimas décadas foram estabelecidas tendências passadas e recentes da prevalência da obesidade (IMC ³ 30 kg/m²) na população adulta da menos desenvolvida (Nordeste) e da mais desenvolvida (Sudeste) região brasileira. No primeiro período de observação (1975-1989), a evolução da obesidade foi ascendente e relativamente uniforme nas duas regiões, com o que não foram alterados o predomínio da enfermidade na Região Sudeste e a tendência de que, dentro das duas regiões, os estratos mais pobres apresentassem-se menos vulneráveis à obesidade. Esse foi também o quadro observado para a população masculina no segundo período de estudo (1989-1997), exceto pelo aumento mais intenso da obesidade na Região Nordeste e pela conseqüente diminuição das diferenças entre as duas regiões. A evolução da obesidade feminina no período 1989-1997 mostrou-se distintamente influenciada pela renda familiar nas duas regiões. Na Região Nordeste, o aumento da obesidade foi modesto para as mulheres mais pobres e intenso para os estratos intermediários e de alta renda. Na Região Sudeste, houve declínio na prevalência da obesidade para os estratos intermediários e de alta renda e aumento intenso para as mulheres mais pobres. Esse padrão socialmente diferenciado da evolução regional da obesidade fez com que, em 1997, o risco da obesidade feminina na Região Nordeste apenas se mantivesse inferior ao da Região Sudeste entre as mulheres mais pobres. Pela magnitude dos contrastes chamou particular atenção a evolução recente da obesidade nos estratos que correspondem aos 25% das mulheres mais ricas de cada região: ascensão dramática no Nordeste - 9,9% para 14,6% -, declínio não menos notável no Sudeste - 13,2% para 8,2%. A tendência de declínio da obesidade documentada para mulheres que vivem na Região Sudeste do país é inédita em países em desenvolvimento, tendo sido, de fato, documentada, até o presente, apenas em populações escandinavas. Embora análises mais aprofundadas sejam necessárias, mostra-se plausível a hipótese de que atividades educativas veiculadas por meios de comunicação de massa possam ter tido um papel relevante no recente declínio da obesidade documentado no Sudeste brasileiro.

Secular trends in the prevalence of obesity in adults (BMI ³ 30 kg/m²) are described in the two more populated Brazilian regions: the less developed Northeast and the more developed Southeast. All data utilized by this study come from three nation-wide large-scale cross-sectional surveys undertaken in 1975, 1989 and 1997. In the first period (1975-1989), obesity increased uniformly for males and females in the two regions and both the excess of the disease in the Southeast and the inverse relationship between income and obesity, existing in the two regions, were not affected. The same situation was also observed for the male population in the second period (1989-1997) except for the relatively higher increase of obesity in the Northeast and the consequent reduction of the gap existing between the two regions. Trends in the prevalence of female obesity in the second period were distinctly influenced by income in the two regions. In the Northeast, increasing trends in female obesity were modest for lower income women and intense for intermediate and higher income groups. In the Southeast, there was a decline in the prevalence of obesity for intermediate and higher income groups and an intense increase for lower income women. These contrasting trends in the prevalence of obesity determined that, in 1997, except for the low income group, female obesity was more common in the Northeast than in the Southeast. The greater difference between the two regions as regard recent trends in obesity was seen for higher income groups (the 25% richest women in each region): a dramatic increase in the Northeast - from 9.9% to 14.6% - and a non less impressive decline in the Southeast - from 13.2% to 8.2%, The declining trends in obesity documented for women living in the Southeast of Brazil were not described yet in any other developing country. In fact, declining trends in obesity as those described in this study were reported, up to now, only for Scandinavian populations. Although much more in-depth analysis is needed, a plausible hypothesis to explain declining trends in female obesity in Brazil is that an intense mass media work focused on combating a sedentary life-style and promoting better food habits has been effective in reaching at least the higher income women in the more developed parts of the country.