Effect of birth size and proportionality on BMI and skinfold thickness in early adolescence: prospective birth cohort study.

OBJECTIVES: To assess the effect of birth weight, length and ponderal index at birth on body mass index (BMI) and skinfold thickness in early adolescence. SUBJECTS/METHODS: Population-based, prospective birth cohort study in Pelotas, Brazil. Out of 5249 cohort members, 87.5% were traced at 11 years of age. Birth weight, length and ponderal index (birth weight/birth length(3) x 100) -- treated as continuous variable and divided into fourths -- were the exposure variables. BMI at 11 years, triceps and subscapular skinfolds were the outcomes. Confounders included sex, gestational age, parity, maternal schooling, family income, maternal smoking during pregnancy and maternal BMI. RESULTS: All three exposure variables were significantly associated with BMI in early adolescence, but the strongest effect was observed for birth weight. Each unit (Z-score) increase in birth weight was associated with 0.46 kg m(-2) increase in BMI at 11 years. The equivalent coefficients for ponderal index and birth length were 0.22 and 0.21 kg m(-2), respectively. High birth weight, length and ponderal index were also associated with increased values for triceps and subscapular skinfolds at 11 years, and with increased prevalence of obesity. CONCLUSIONS: Of the three birth exposures studied, birth weight presented the strongest effect on anthropometry in early adolescence. Ponderal index, a proportionality indicator associated with infant mortality, hospitalizations and anthropometry in infancy, was also associated with anthropometry in early adolescence, but its predictive value for the latter is lower than that of birthweight alone. All three birth size indicators studied presented poor predictability of the later risk of obesity.

Overweight and obesity in Brazilian adolescents.

OBJECTIVE: This study aimed to describe the prevalence of overweight and obesity (OW+O) among Brazilian adolescents and to identify risks for subpopulations defined according to the five country macro-regions and situation (urban-rural) of the domiciles, income, years of school attendance, age and sex. DESIGN: A nationwide home-based survey representative of the Brazilian civilian noninstitutionalized population, performed in 1989. METHODS: The sampling plans followed a stratified, multistage, probability cluster design in The National Research of Health and Nutrition sample, which collected anthropometric data of 14,455 domiciles. In all, 13,715 adolescents ranging from 10 to 19 y of age were studied. The OW+O was defined from a body mass index (BMI) equal or superior to the 85th percentile of the reference population of the NCHS. The prevalences in the different studied groups were compared using the adjusted odds ratio in logistic regression models. RESULTS: The prevalence of OW+O was of 7.7%, reaching 10.6% within the female group and 4.8% within the male group. A direct relation could be established between the socioeconomic level and OW+O. Adolescents of the most industrialized region of the country presented a risk of OW+O 1.86 (95% CI 1.51-2.30) times higher than that found in the least developed region. Male youngsters who lived in urban areas were more liable (OR=1.71, 95% CI 1.30-2.25) to overweight than their counterparts of rural areas. The occurrence of menarche increased two and a half times (OR=2.58, 95% CI 2.11-3.15) the risk of OW+O within the female group of adolescents. CONCLUSIONS: The results demonstrate a low prevalence of OW+O among Brazilian adolescents when compared with adolescents of more industrialized regions. The OW+O is twice as high within the female group, which represents a much greater difference than the one encountered in industrialized countries, probably owing to the muscular work carried out preponderantly by male adolescents of lower socioeconomic levels. Higher prevalences in subpopulations of higher socioeconomic level and of more industrialized regions show the great need for differentiated actions to control overweight and obesity in the country.

[Measuring the impact of promoting breastfeeding in primary health care services in Pelotas, Rio Grande do Sul, Brazil]. / Medindo o impacto da promoção do aleitamento materno em serviços de atenção primária à Saúde em Pelotas, Rio Grande do Sul, Brasil.

All mothers with children enrolled in the Program for Child Growth and Development at primary care units belonging to the Federal University of Pelotas (UFPel) in the state of Rio Grande do Sul, Brazil, were interviewed with a standardized questionnaire. This research aimed to assess the impact of the "Groups of Expecting Mothers" in the promotion of breastfeeding. The family income of almost half of the 347 children studied was two times the minimum wage. About 1/4 of the children's mothers had spent less than four years in school, and these were the mothers who attended the Groups most frequently. Most of the mothers received prenatal care and nearly half of then participated in the Groups. In contrast, 1/3 of the children were weaned at the age of three months and almost 80% received tea in the early months of life. The results show that the Groups of Expecting Mothers suffer serious limitations in promoting breastfeeding and in postponing the introduction of foods other than breast milk in the children's diet. Data obtained in this study are intended to help strengthen action under current programs and to show that with minimum resources and a rather simple methodology it is possible to assess the quality of health services available to the population.