Two-year controlled effectiveness trial of a school-based intervention to prevent obesity in Chilean children (original) (raw)
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British Journal of Sports Medicine, 2014
Background School-based interventions that target prevention of overweight and obesity in children have been tested with mixed results. Thus, successful interventions are still called for. The aim of the present study was to investigate effects of a multicomponent school-based intervention programme targeting physical activity, sedentary and dietary behaviours on anthropometric outcomes. Methods A 20-month intervention was evaluated in a cluster randomised, controlled study of 1324 11-yearolds. Outcome variables were body mass index (BMI), BMI-for-age z-score (BMIz), waist circumference (WC), waist-to-height ratio (WTHR) and weight status (International Obesity Task Force's cut-offs). Weight, height and WC were measured objectively; pubertal status was self-reported and parental education was self-reported by the parents. Intervention effects were determined by one-way analysis of covariance and logistic regression, after checking for clustering effects of school, and moderating effects of gender, pubertal status and parental education. Results Beneficial effects were found for BMI ( p=0.02) and BMIz ( p=0.003) in girls, but not in boys. While a beneficial effect was found for BMI ( p=0.03) in participants of parents reporting a high level of education, a negative effect was found for WTHR in participants with parents reporting a low level of education ( p=0.003). There were no intervention effects for WC and weight status. Conclusions A multicomponent 20-month schoolbased intervention had a beneficial effect on BMI and BMIz in adolescent girls, but not in boys. Furthermore, children of higher educated parents seemed to benefit more from the intervention, and this needs attention in future interventions to avoid further increase in social inequalities in overweight and obesity.
2014
Background: Obesity is one of the main determinants of avoidable disease burden. To implement a program by university students acting as "health promoting agents" (HPAs) and to evaluate the effects on obesity prevalence of the primary-school-based program that promotes healthy lifestyle, including dietary and physical activity recommendations over 28 months. Methods: Two school clusters were randomly assigned to intervention (24 schools, 1,222 pupils) or control (14 schools, 717 pupils); 78% of pupils were Western European. Mean age (±SD) was 8.4 ± 0.6 years (49.9% females) at baseline. Generalized linear mixed models were used to analyze differences in primary outcome between both groups. Data collected included body mass index (BMI) every year. Dietary habits and lifestyle questionnaires were filled in by the parents at baseline and at the end of the study. The interventions focused on eight lifestyle topics covered in 12 activities (1 hour/activity/session) implemented by HPAs over 3 school academic years. Results: At 28 months, obesity prevalence in boys was decreased −2.36% in the intervention group (from 9.59% to 7.23%) and increased 2.03% (from 7.40% to 9.43%) in the control group; the difference was 4.39% (95% CI 3.48 to 5.30; P = 0.01). The boys in the intervention group had an effective reduction of −0.24 units in the change of BMI z-score (from 0.01 to −0.04), compared to control (from −0.10 to 0.09); 5.1% more intervention pupils undertook physical activity >5 hours/week than control pupils (P = 0.02). Fish consumption was a protector (odds ratio 0.39; 95% CI 0.23 to 0.67) while "fast-food" consumption was a risk factor for childhood obesity (odds ratio: 2.27; 95% CI 1.08 to 4.77).
Journal of Obesity, 2014
Objective. To evaluate the effectiveness of a 12-month multicomponent obesity prevention intervention. Setting. 9 elementary schools in Santiago, Chile. Subjects. 6-8 y old low-income children (= 1474). Design. Randomized controlled study; 5 intervention/4 control schools. We trained teachers to deliver nutrition contents and improve the quality of PE classes. We determined % healthy snacks brought from home, children's nutrition knowledge, nutritional status, duration of PE classes, and % time in moderate/vigorous activity (MVA). Effectiveness was determined by comparing Δ BMI Z between intervention and control children using PROCMIXED. Results. % obesity increased in boys from both types of schools and in girls from control schools, while decreasing in girls from intervention schools (all nonsignificant). % class time in MVA declined (24.5-16.2) while remaining unchanged (24.8-23.7%) in classes conducted by untrained and trained teachers, respectively. In boys, BMI Z declined (1.33-1.24) and increased (1.22-1.35) in intervention and control schools, respectively. In girls, BMI Z remained unchanged in intervention schools, while increasing significantly in control schools (0.91-1.06, = 0.024). Interaction group * time was significant for boys (< 0.0001) and girls (= 0.004). Conclusions. This intervention was effective in controlling obesity, but not preventing it. Even though impact was small, results showed that when no intervention is implemented, obesity increases.
Pediatrics, 2016
This study examined the long-term effects on BMI of a randomized controlled trial of Students for Nutrition and Exercise, a 5-week, middle school-based obesity prevention intervention combining school-wide environmental changes, encouragement to eat healthy school cafeteria foods, and peer-led education and marketing. We randomly selected schools from the Los Angeles Unified School District and assigned 5 to the intervention group and 5 to a wait-list control group. Of the 4022 seventh-graders across schools, a total of 1368 students had their height and weight assessed at baseline and 2 years' postintervention. A multivariable linear regression was used to predict BMI percentile at ninth grade by using BMI percentile at seventh grade, school indicators, and sociodemographic characteristics (child gender, age, Latino race/ethnicity, US-born status, and National School Lunch Program eligibility [as a proxy for low-income status]). Although the Students for Nutrition and Exercise ...
Nutrición hospitalaria
The objective of this study, focused on parents and children to reduce sedentary behavior, consumption of soft drinks and high-fat and salt containing snacks, and increase the consumption of fruits and vegetables, was to assess the effect of a six month intervention and an 18 month follow-up intervention on the body mass index, food consumption and physical activity of 2nd and 3rd grade elementary school children. This was a randomized cluster controlled trial. School children were selected from 2nd and 3rd (n = 532) grade. BMI z-score for age and sex was calculated and classified according to the WHO (2006). Abdominal obesity was defined as WC > 90th of NHANES III. At six months of the study differences were observed in BMI, -0.82 (p = 0.0001). At 24 months, results such as an increase of z-score BMI and waist circumference, a decrease in abdominal obesity, eighth per cent remission and an incidence of 18% of overweight and obesity were observed. Additionally, an increase (p = 0...
BMC Pediatrics, 2014
Obesity amongst children is a growing problem worldwide. In contrast to adults, little is known on the effects of controlled weight loss on components of the metabolic syndrome in children. The primary aim of the study was to evaluate the effects of a 20-week exercise and diet guidance intervention on body mass index (BMI) in a group of overweight children. Our hypothesis was an observed reduction in BMI and secondarily in body fat content, insulin insensitivity, and other components of the metabolic syndrome in the intervention group.
Advances in nutrition (Bethesda, Md.), 2012
Obesity in Chilean children has increased markedly over the past decades. School-based obesity prevention interventions have been launched by the Ministry of Health and academic groups to tackle this condition. We summarize the main characteristics of the interventions that we have conducted and reflect on the lessons learned. Since 2002, we conducted 1 pilot study, a 2-y controlled intervention including 6- to 12-y-old children (Casablanca), another pilot study, and a 2-y controlled intervention including teachers and their 4- to 9-y-old students (Macul). Both interventions consisted of training teachers to deliver contents on healthy eating, increasing physical education classes, and, additionally in Macul, teachers participated in a wellness program. BMI Z-score and obesity prevalence were compared among children in intervention and control schools by year and among students of intervention and control teachers. In the Casablanca study, the impact was greatest on the younger chil...
Overweight Prevention Implemented by Primary School Teachers: A Randomised Controlled Trial
Obesity Facts, 2012
Objective: To describe the effects of URMEL-ICE, a German school-based intervention for overweight prevention, on children's BMI and other measures of fat mass. Methods: A clusterrandomised controlled design was used. The intervention which focused on physical activity, TV time and soft drink consumption was integrated into a second-grade curriculum and was implemented by classroom teachers themselves. It comprised 29 teaching lessons, 2 short exercise blocks per day and 6 family homework lessons. BMI was assessed as primary outcome measure, waist circumference and skinfold thickness as secondary outcomes. Data of 945 children were analysed. Results: Multivariate analyses adjusted for baseline values showed no statistically significant effect of the intervention on BMI, but on waist circumference (-0.85; 95% confidence interval (95% CI)-1.59 to-0.12) and subscapular skinfold thickness (-0.64; 95% CI-1.25 to-0.02). After additional adjustment for individual time lag between baseline and follow-up, these effects were reduced to-0.60 (95% CI-1.25 to 0.05) and-0.61 (95% CI-1.26 to 0.04) and lost their statistical significance. Conclusion: This study contributes to the field of randomised school-based studies on overweight prevention and shows that within a 1-year, integrated intervention no effect on BMI, but a tendency towards effects on fat mass can be achieved.
Preventive Medicine Reports, 2021
This mixed methods study aimed to examine plausible body mass index (BMI) trajectories after exposure to a primary school-based lifestyle intervention to aid in estimating the long-term intervention benefits. BMI trajectories for children at control schools (mean 7.6 years of age) were modelled until 20 years of age through extrapolating trial evidence (N = 1647). A reference scenario assumed that the observed 2-year effects of the 'Healthy Primary Schools of the Future' (HPSF) and 'Physical Activity Schools' (PAS) were fully maintained over time. This was modelled by applying the observed 2-year BMI effects until 20 years of age. Expert opinions on likely trends in effect maintenance after the 2-year intervention period were elicited qualitatively and quantitatively, and were used for developing alternative scenarios. Expert elicitation revealed three scenarios: (a) a constant exposure-effect and an uncontrolled environment with effect decay scenario, (b) a household multiplier and an uncontrolled environment with effect decay scenario, and (c) a household multiplier and maintainer scenario. The relative effect of HPSF at 20 years of age was − 0.21 kg/m 2 under the reference scenario, and varied from − 0.04 kg/m 2 (a) to − 0.06 kg/m 2 (b), and − 0.50 kg/ m 2 (c). For PAS, the relative effect was − 0.17 kg/m 2 under the reference scenario, and varied from − 0.04 kg/m 2 (a, b), to − 0.21 kg/m 2 (c). The mixed methods approach proved to be useful in modelling plausible BMI trajectories and specifying uncertainty on effect maintenance. Further observations until adulthood could reduce the uncertainty around future benefits. This trial was retrospectively registered at Clinicaltrials.gov (NCT02800616).