Prospective Findings From the 1993 Pelotas (Brazil) Birth Cohort Study

v r w i a w This supplement to the Journal of Adolescent Health is devoted o understanding the health and well-being of adolescents by aking the long view of this period of the life cycle. The articles erein analyze data collected from conception through age 15 rom 4,500 individuals born in the city of Pelotas, Brazil, in 1993. he analyses provide us with not just a snapshot of adolescents’ urrent health status, but rather an entire movie depicting the ife-course trajectories and the emergence of health outcomes of his population during adolescence. The first four articles of the supplement focus on early-life redictors of later health and behavior [1–4]. Wells et al show hat infant weight and length gains were associated primarily ith larger size in adolescence rather than increased adiposity, lthough later childhood gains inweight and heightwere predicors of fat mass [1]. In the second article, MartÎnez-Mesa et al eport that maternal smoking during pregnancy negatively afects an offspring’s height in adolescence [2]. The third and ourth articles report on the effect of socioeconomic change from irth to adolescence [3,4]. Hallal et al show that adolescents born ohigh-income families hadhalf the odds ofwalking or cycling to chool compared with those whose families became wealthy uring adolescence, suggesting that the habit of commuting to chool under one’s own power was “built” early in life [3]. Anelmi et al examine the influence of poverty on mental health, howing that both persistent poverty and becoming poor over ime were associated with a greater likelihood of developing onduct disorders in adolescence [4]. The next three articles focus on the health effects of behavoral changes during adolescence [5–7]. Menezes et al report a ositive association between self-reported physical activity ractice in adolescence and effort-dependent lung function, paricularly among girls [5]. In contrast, Rombaldi et al show that too uch time dedicated to physical activity ( 1,000 min/wk) may eopardize school performance [6]. In addition, Noal et al report hat the prevalence of wheezing at 15 years of age was 53% reater among obese versus nonobese adolescents [7]. The next three articles further explore environmental factors hat influence obesity and perceptions of obesity from the perspecive of parents and adolescents [8–10]. AssunÈÄo et al explore preictors of nutritional status change, finding that low-income girls ere more likely than high-income girls to become obese from 11 o 15 years, and that high-income boys were more likely than ow-incomeboys to ceasebeingobeseduringadolescence [8]. Body ass index tracked strongly during adolescence, suggesting that