Rita Adriana Gomes de Souza

School randomised trial on prevention of excessive weight gain by discouraging students from drinking sodas

OBJECTIVE To determine whether an educational programme aimed at discouraging students from drinking sugar-sweetened beverages could prevent excessive weight gain. DESIGN Forty-seven classes in twenty-two schools were randomised as intervention or control. SUBJECTS Participants were 1140, 9-12-year-old fourth graders (435 in the intervention group and 608 in the control group). Sugar-sweetened beverages and juice intake were measured through one 24 h recall at baseline and another at the end of the trial. The main outcome was the change in BMI (BMI = weight (kg)/height (m2)), measured at the beginning and at the end of the school year. Intention-to-treat analysis was performed taking into account the cluster (classes) effect. RESULTS A statistically significant decrease in the daily consumption of carbonated drinks in the intervention compared to control (mean difference = -56 ml; 95 % CI -119, -7 ml) was followed by a non-significant overall reduction in BMI, P = 0.33. However, among those students overweight at baseline, the intervention group showed greater BMI reduction (-0.4 kg/m2 compared with -0.2 kg/m2 in the control group (P = 0.11)), and this difference was statistically significant among girls (P = 0.009). Fruit juice consumption was slightly increased in the intervention group (P = 0.08), but not among girls. CONCLUSION Decreasing sugar-sweetened beverages intake significantly reduced BMI among overweight children, and mainly among girls. Efforts to reduce energy intake through liquids need to emphasise overall sweetened beverages and addition of sugar on juices.

Estratégias para prevenção da obesidade em crianças e adolescentes

Few studies on treatment or prevention of obesity have shown significant results. Theoretically, in children and adolescents as compared to adults, prevention of excessive weight gain should be easy due to the energy expended during growth, associated with more time spent in leisure-time activities. However, numerous factors that stimulate overeating and sedentary behaviors are difficult to overcome. Additionally, most intervention studies have focused on a minor portion of the many factors associated with obesity. Important aspects of the obesity epidemic such as the role of the food industry, fast food chains, advertising, and a lifestyle that limits children to sedentary activities and overeating cannot be explored by a traditional clinical trial design. At any rate, among the published interventions, those including the family in weight-reduction strategies have shown the best results, as compared to children-centered approaches. Meanwhile, studies on specific nutrient or dietary composition (such as calcium, protein, or glycemic index) related to prevention or treatment of obesity have failed to yield good results. Reducing the intake of high-sugar carbonated drinks and juices has shown promising but still inconclusive results.

Consumo de cafeína e prematuridade

Caffeine (1, 3, 7-trimethylxanthine) is a methylxanthine that easily crosses the placental barrier, substantial amounts passing into the amniotic fluid, umbilical cord blood, and the plasma and urine of the neonates. The main sources of caffeine are coffee, tea, chocolate and cola soft drinks. Moreover, about 1000 prescribed drugs and 2000 non-prescribed drugs contain caffeine, and 25 of these drugs can be used during pregnancy. Although animal studies indicate that caffeine leads to a decrease in fetal intrauterine growth, low birth weight, fetal re-absorption and teratogenesis, these findings are still inconclusive in the epidemiological studies. Since foods containing caffeine are widely consumed during pregnancy, it is important to evaluate if the consumption of this substance is associated with a reduction in gestational age. This article examines current knowledge on caffeine intake during pregnancy, based on epidemiological studies evaluating the association between caffeine intake and prematurity, the sources of caffeine and its consumption during pregnancy, the biochemistry, physiopathology and biological plausibility of the association, and the main limitations of the studies on caffeine and prematurity.

Consumo de cafeína e de alimentos-fonte de cafeína e prematuridade: um estudo caso-controle

Caffeine (1,3,7-trimethylxanthine) is an alkali that easily crosses the placental barrier and can interfere in the growth and development of fetal cells and compromise fetal oxygenation. Considering the widespread consumption of foods containing caffeine in Brazil, the aim of this study was to evaluate the association between total caffeine consumption (including its food sources) and prematurity. A case-control study of 140 cases (newborns with gestational age less than 37 weeks) and 162 controls (newborns with 37 weeks gestational age or greater) evaluated caffeine consumption during pregnancy. Intake measurement used a semi-quantitative food frequency questionnaire based on the following foods: coffee, tea, and powdered chocolate. Total caffeine consumption (including food sources) during pregnancy was not associated with prematurity, and most intakes were less than 300 mg/ day. Caffeine consumption in the present study does not support guidelines against caffeine consumption by Brazilian pregnant women.

Effectiveness of a home-based exercise program on anthropometric and metabolic changes among school cooks

The scope of this study was to evaluate the anthropometric and metabolic changes after low intensity home-based exercise. In the school year of 2007, 95 school cooks in the city of Niteroi (State of Rio de Janeiro, Brazil) were randomly assigned to one of the following groups: home-based exercise (n = 47) or control group (n = 48). The home-based exercise program was performed three times a week, during 40 minutes at moderate intensity. Anthropometric variables were collected at the baseline and after 4 and 8 months, whereas biochemical and individual food intake were measured at the baseline and after 8 months. Energy expenditure was evaluated only at the baseline. The home-based exercise group exhibited a greater weight loss (-0.9 vs. -0.2; p = 0.05) in comparison with controls during the follow-up and the same pattern was found for BMI (-0.1 vs. +0.1; p = 0.07), although without statistical significance. Exercise showed no effects on waist circumference, lipid profile and glucose. In conclusion, greater weight loss was observed in the group that performed low intensity home-based exercise and this strategy can assist in body weight control even without alterations in terms of lipids and glucose.

Effects of socioeconomic position and social mobility on linear growth from early childhood until adolescence

OBJECTIVE To assess the effect of socioeconomic position (SEP) in childhood and social mobility on linear growth through adolescence in a population-based cohort. METHODS Children born in Cuiabá-MT, central-western Brazil, were evaluated during 1994 - 1999. They were first assessed during 1999 - 2000 (0 - 5 years) and again during 2009 - 2011 (10 - 17 years), and their height-for-age was evaluated during these two periods.Awealth index was used to classify the SEP of each childs family as low, medium, or high. Social mobility was categorized as upward mobility or no upward mobility. Linear mixed models were used. RESULTS We evaluated 1,716 children (71.4% of baseline) after 10 years, and 60.6% of the families showed upward mobility, with a higher percentage among the lowest economic classes. A higher height-for-age was also observed among those from families with a high SEP both in childhood (low SEP= -0.35 z-score; high SEP= 0.15 z-score, p < 0.01) and adolescence (low SEP= -0.01 z-score; high SEP= 0.45 z-score, p < 0.01), whereas upward mobility did not affect their linear growth. CONCLUSION Expressive social mobility was observed, but SEP in childhood and social mobility did not greatly influence linear growth through childhood in this central-western Brazilian cohort.

As autoras respondem

com esta perspectiva de generalizacao, uma vez que a efetividade de cada intervencao esta asso-ciada ao contexto socio-economico e cultural da realidade em que ela foi experimentada.4) O fato de que, no âmbito das politicas pu-blicas, as intervencoes voltadas a prevencao da obesidade devam ser abrangentes e integradas impoe a pesquisadores da area o desafio de in-tegrar diferentes metodologias de pesquisa para seu delineamento e avaliacao. Ensaios clinicos randomizados nao sao suficientes e, em algu-mas situacoes, nao sao os mais adequados para subsidiar a formulacao e a avaliacao de inter-vencoes