School environments and obesity: a systematic review of interventions and policies among school-age students in Latin America and the Caribbean.

BACKGROUND: The rapid rise in obesity rates among school children in Latin America and the Caribbean (LAC) could have a direct impact on the region's physical and mental health, disability, and mortality. This review presents the available interventions likely to reduce, mitigate and/or prevent obesity among school children in LAC by modifying the food and built environments within and around schools. METHODS: Two independent reviewers searched five databases: MEDLINE, Web of Science, Cochrane Library, Scopus and Latin American and Caribbean Health Sciences Literature for peer-reviewed literature published from 1 January 2000 to September 2021; searching and screening prospective studies published in English, Spanish and Portuguese. This was followed by data extraction and quality assessment using the Cochrane risk-of-bias tool (RoB 2) and the Risk of Bias in Non-Randomized Studies of Interventions (ROBINS-I), adopting also the PRISMA 2020 guidelines. Due to the heterogeneity of the intervention's characteristics and obesity-related measurements across studies, a narrative synthesis was conducted. RESULTS: A total of 1342 research papers were screened, and 9 studies were included; 4 in Mexico, and 1 each in Argentina, Brazil, Chile, Colombia, and Ecuador. Four studies reported strategies for modifying food provision; four other targeted the built environment, (modifying school premises and providing materials for physical activity); a final study included both food and built environment intervention components. Overall, two studies reported that the intervention was significantly associated with a lower increase over time in BMI/obesity in the intervention against the control group. The remaining studies were non-significant. CONCLUSIONS: Data suggest that school environmental interventions, complementing nutritional and physical education can contribute to reduce incremental childhood obesity trends. However, evidence of the extent to which food and built environment components factor into obesogenic environments, within and around school grounds is inconclusive. Insufficient data hindered any urban/rural comparisons. Further school environmental intervention studies to inform policies for preventing/reducing childhood obesity in LAC are needed.

Does pre-school improve cognitive abilities among children with early-life stunting? A longitudinal study for Peru.

Several studies in developing countries have found that children who experience growth faltering in the first years of life show lower cognitive abilities than their peers. In this study, we use the Young Lives longitudinal dataset in Peru to analyze if attending pre-school affects cognitive abilities at age five years, and if there is an interaction with HAZ at age one year. Using instrumental variables we found, for receptive vocabulary, a positive effect of attending Jardines (formal) pre-schools; the effect of attending PRONOEI (community-based) pre-schools was not significant. More years attending Jardines was more beneficial for children who were better nourished. We suggest working to improve the quality of PRONOEIs, and with teachers on targeting children of lower nutritional status.

What difference can fathers make? Early paternal absence compromises Peruvian children's growth.

Considerable evidence suggests that fathers' absence from home has a negative short- and long-term impact on children's health, psychosocial development, cognition and educational experience. We assessed the impact of father presence during infancy and childhood on children's height-for-age z-score (HAZ) at 5 years old. We conducted secondary data analysis from a 15-year cohort study (Young Lives) focusing on one of four Young Lives countries (Peru, n = 1821). When compared with children who saw their fathers on a daily or weekly basis during infancy and childhood, children who did not see their fathers regularly at either period had significantly lower HAZ scores (-0.23, P = 0.0094) after adjusting for maternal age, wealth and other contextual factors. Results also suggest that children who saw their fathers during childhood (but not infancy) had better HAZ scores than children who saw their fathers in infancy and childhood (0.23 z-score, P = 0.0388). Findings from analyses of resilient children (those who did not see their fathers at either round but whose HAZ > -2) show that a child's chances of not being stunted in spite of paternal absence at 1 and 5 years old were considerably greater if he or she lived in an urban area [odds ratio (OR) = 9.3], was from the wealthiest quintile (OR = 8.7) and lived in a food secure environment (OR = 3.8). Interventions designed to reduce malnutrition must be based on a fuller understanding of how paternal absence puts children at risk of growth failure.

Developmental potential in the first 5 years for children in developing countries.

Many children younger than 5 years in developing countries are exposed to multiple risks, including poverty, malnutrition, poor health, and unstimulating home environments, which detrimentally affect their cognitive, motor, and social-emotional development. There are few national statistics on the development of young children in developing countries. We therefore identified two factors with available worldwide data--the prevalence of early childhood stunting and the number of people living in absolute poverty--to use as indicators of poor development. We show that both indicators are closely associated with poor cognitive and educational performance in children and use them to estimate that over 200 million children under 5 years are not fulfilling their developmental potential. Most of these children live in south Asia and sub-Saharan Africa. These disadvantaged children are likely to do poorly in school and subsequently have low incomes, high fertility, and provide poor care for their children, thus contributing to the intergenerational transmission of poverty.

Disparities in children's vocabulary and height in relation to household wealth and parental schooling: A longitudinal study in four low- and middle-income countries.

Children from low socio-economic status (SES) households often demonstrate worse growth and developmental outcomes than wealthier children, in part because poor children face a broader range of risk factors. It is difficult to characterize the trajectories of SES disparities in low- and middle-income countries because longitudinal data are infrequently available. We analyze measures of children's linear growth (height) at ages 1, 5, 8 and 12y and receptive language (Peabody Picture Vocabulary Test) at ages 5, 8 and 12y in Ethiopia, India, Peru and Vietnam in relation to household SES, measured by parental schooling or household assets. We calculate children's percentile ranks within the distributions of height-for-age z-scores and of age- and language-standardized receptive vocabulary scores. We find that children in the top quartile of household SES are taller and have better language performance than children in the bottom quartile; differences in vocabulary scores between children with high and low SES are larger than differences in the height measure. For height, disparities in SES are present by age 1y and persist as children age. For vocabulary, SES disparities also emerge early in life, but patterns are not consistent across age; for example, SES disparities are constant over time in India, widen between 5 and 12y in Ethiopia, and narrow in this age range in Vietnam and Peru. Household characteristics (such as mother's height, age, and ethnicity), and community fixed effects explain most of the disparities in height and around half of the disparities in vocabulary. We also find evidence that SES disparities in height and language development may not be fixed over time, suggesting opportunities for policy and programs to address these gaps early in life.

Height, weight, and education achievement in rural Peru.

The education system in Peru and many other developing countries faces several challenges, including improving education achievement and increasing education enrollment in high school. It is clear from several indicators that rural students have lower education outcomes than do urban students. In this study we used cross-sectional and longitudinal analysis to determine the relationship between height-for-age z-scores (HAZ), weight-for-age z-scores (WAZ), body-mass index (BMI), and education outcomes. The sample was composed of students from 20 elementary public schools in two rural zones in Peru. The descriptive results show that there was no association between any of the anthropometric variables and achievement (mathematics and reading comprehension) or advancing to high school without repeating a grade. However, BMI was associated with dropping out of school: children with higher BMI in 1998 were more likely to be out of school by 2001. The hierarchical multivariate analysis also showed no relationship between anthropometry and achievement at the individual level, but students with relatively higher HAZ in 1998 were more likely to be drop-outs by 2001. These results contradict prior findings that showed a positive association between anthropometric variables (especially HAZ) and education achievement. The results might be explained by the fact that the study was carried out at very poor sites, at altitudes between 3000 and 3500 meters above sea level. The scarce studies about development in high altitudes suggest that the patterns for height and weight for children and adolescents are different than at sea level. Another possible explanation has to do with the fact that in the contexts studied, children who are perceived as relatively heavier (BMI) or taller (HAZ) might be expected to be out of school and start working (in fact, this was the primary reason given by children for dropping out of school).

Postinfancy growth, schooling, and cognitive achievement: Young Lives.

BACKGROUND: Early life growth failure and resulting cognitive deficits are often assumed to be very difficult to reverse after infancy. OBJECTIVE: We used data from Young Lives, which is an observational cohort of 8062 children in Ethiopia, India, Peru, and Vietnam, to determine whether changes in growth after infancy are associated with schooling and cognitive achievement at age 8 y. DESIGN: We represented the growth by height-for-age z score at 1 y [HAZ(1)] and height-for-age z score at 8 y that was not predicted by the HAZ(1). We also characterized growth as recovered (stunted at age 1 y and not at age 8 y), faltered (not stunted at age 1 y and stunted at age 8 y), persistently stunted (stunted at ages 1 and 8 y), or never stunted (not stunted at ages 1 and 8 y). Outcome measures were assessed at age 8 y. RESULTS: The HAZ(1) was inversely associated with overage for grade and positively associated with mathematics achievement, reading comprehension, and receptive vocabulary. Unpredicted growth from 1 to 8 y of age was also inversely associated with overage for grade (OR range across countries: 0.80-0.84) and positively associated with mathematics achievement (effect-size range: 0.05-0.10), reading comprehension (0.02-0.10), and receptive vocabulary (0.04-0.08). Children who recovered in linear growth had better outcomes than did children who were persistently stunted but were not generally different from children who experienced growth faltering. CONCLUSIONS: Improvements in child growth after early faltering might have significant benefits on schooling and cognitive achievement. Hence, although early interventions remain critical, interventions to improve the nutrition of preprimary and early primary school-age children also merit consideration.

Relation of neonatal iron status to individual variability in neonatal temperament.

The relation between indices of neonatal iron status and individual differences in neonatal temperament were investigated in a sample of 148 low-income Peruvian women and their newborn infants. Using cord blood, at birth we obtained measures of neonatal ferritin, serum iron, and hemoglobin. While neonates were still in the hospital, their behavior during a structured anthropometry examination was videotaped and subsequently coded on four temperament dimensions: activity level, negative emotionality, alertness, and soothability. The same dimensions were coded using a videotape obtained during a subsequent visit to the neonates' homes. Results indicated that lower levels of neonatal hemoglobin and serum iron were related to higher levels of negative emotionality and to lower levels of alertness and soothability. A similar pattern was found for ferritin, but only for females. For the most part, relations between neonatal iron measures and neonatal temperament were linear, operating across the full range of iron values. Our pattern of iron-temperament results could not be attributed to variation in family demographics, low birth weight, gestational age, maternal dietary intake, or markers of neonatal illness and maternal diabetes. Our findings are consistent with prior research with older infants relating iron deficiency to temperament. These results support the importance of increased research on the early functional-behavioral consequences of individual differences in iron status as well as on the mechanisms that underlie such consequences.

Maternal education and intelligence predict offspring diet and nutritional status.

The traditional assumption that children's nutritional deficiencies are essentially due either to overall food scarcity or to a lack of family resources to purchase available food has been increasingly questioned. Parental characteristics represent 1 type of noneconomic factor that may be related to variability in children's diets and nutritional status. We report evidence on the relation of 2 parental characteristics, maternal education level and maternal intelligence, to infant and toddler diet and nutritional status. Our sample consisted of 241 low-income Peruvian mothers and their infants assessed from 3 to 12 mo, with a further follow-up of 104 of these infants at 18 mo of age. Using a nonexperimental design, we related measures of level of maternal education, maternal intelligence, and family socioeconomic status to infant anthropometry, duration of exclusive breast-feeding, adequacy of dietary intake, and iron status. Results indicated unique positive relations between maternal education level and the extent of exclusive breast-feeding. Significant relations between maternal education and offspring length were partially mediated by maternal height. There also were unique positive relations between maternal intelligence and quality of offspring diet and hemoglobin level. All findings remained significant even after controlling for family socioeconomic characteristics. This pattern of results illustrates the importance of parental characteristics in structuring the adequacy of offspring diet. Maternal education and intelligence appear to have unique influences upon different aspects of the diet and nutritional status of offspring.

Programas efectivos para la prevención del abuso de drogas / Effective programs for the prevention drugs

Presenta una revisión de la literatura sobre la efectividad de programas de prevención de drogas en escuelas Norteamericanas. Recientes estudios han encontrado que programas basados en tácticas de miedo y programas de corto plazo no tienen mayor efecto en la prevención del abuso de drogas. Otras investigaciones han encontrado que programas cognitivos y efectivos de prevención, aún cuando puedan parecer efectivos a-priori, son insuficientes para prevenir el abuso de drogas en la juventud. En este artículo se presentan las características de programas efectivos de prevención de drogas, luego de lo cual se analiza la validez externa de estos estudios para programas de prevención en el Perú

Determinants of school performanceamong quechua children in the peruvian Andes

Examina la proposición de que los factores familiares y personales en combinación con las características de la escuela, contribuyen al progreso académico de los escolares. Trata de explicar la variabilidad en los logros escolares de los niños quechua hablantes del cuarto y quinto grado en diez escuelas primarias rurales en Huaraz, en los Andes centrales del Perú