Abstract

Background:

Schools have become a key figure for the promotion of health and obesity interventions, bringing the development of critical awareness to the construction and promotion of a healthy diet, physical activity, and the monitoring of the nutritional status in childhood and adolescence.

Objectives:

To describe a study protocol to evaluate the effectiveness of an intervention designed to improve knowledge of food choices in the school environment.

Methods:

This is a cluster-randomized, parallel, two-arm study conducted in public elementary and middle schools in Brazil. Participants will be children and adolescents between the ages of 5 and 15 years, from both genders. The interventions will be focusing on changes in lifestyle, physical activities and nutritional education. Intervention activities will occur monthly in the school’s multimedia room or sports court. The control group arm will receive usual recommendations by the school. The primary outcome variable will be anthropometric measures, such as body mass index percentiles and levels of physical activity by the International Physical Activity Questionnaire.

Results:

We expect that after the study children will increase the ingestion of fresh food, reduce excessive consumption of sugary and processed foods, and reduce the hours of sedentary activities.

Conclusion:

The purpose of starting the dietary intervention at this stage of life is to develop a knowledge that will enable for healthy choices, providing opportunities for a better future for this population.

Keywords:
Schools; Health Promotion; Health Behavior; Obesity; Motor Activity; Diet, Food and Nutrition; Body Weight; Prevention & Control

Resumo

Fundamento:

As escolas tornaram-se essenciais para a promoção de saúde e de intervenções para obesidade, propiciando o desenvolvimento de consciência crítica para a construção e promoção de dieta saudável, atividade física e monitoramento do status nutricional na infância e adolescência.

Objetivos:

Descrever um protocolo de estudo para avaliar a eficiência de uma intervenção projetada para aprimorar o conhecimento sobre escolhas alimentares no ambiente escolar.

Métodos:

Estudo clínico randomizado em cluster, paralelo, de dois braços, conduzido em escolas públicas de ensino fundamental e médio no Brasil. Os participantes serão crianças e adolescentes entre 5 e 15 anos de idade, dos dois sexos. As intervenções se concentrarão em mudanças de estilo de vida, atividade física e educação nutricional. As atividades de intervenção ocorrerão mensalmente na sala de multimídia ou quadra de esportes das escolas. O grupo controle receberá as recomendações usuais através da escola. O desfecho primário será a mudança nas medidas antropométricas, como índice de massa corporal e os níveis de atividade física conforme o Questionário Internacional de Atividade Física.

Resultados:

Esperamos que, após o estudo, as crianças aumentem o consumo de alimentos frescos, reduzam o consumo excessivo de alimentos açucarados e processados, e reduzam as horas gastas em atividades sedentárias.

Conclusão:

O propósito de iniciar a intervenção dietética nessa fase da vida é desenvolver o conhecimento que permitirá escolhas saudáveis, propiciando oportunidades para um melhor futuro para essa população.

Palavras-chave:
Escolas; Promoção da Saúde; Comportamentos Saudáveis; Obesidade; Atividade Motora; Dieta; Alimentos e Nutrição; Peso Corporal; Prevenção &Controle

Introduction

The increased prevalence of obesity and its complications reinforces the global need for improved prevention strategies.¹1 Popkin BM. The nutrition transition and its health implications in lower-income countries. Public Health Nutr. 1998;1(1):5-21.

2 Popkin BM, Gordon-Larsen P. The nutrition transition: worldwide obesity dynamics and their determinants. Int J Obes Relat Metab Disord. 2004;28(Suppl 3):S2-S9.^-33 Roberto CA, Swinburn B, Hawkes C, Huang TT, Costa SA, Ashe M, et al. Patchy progress on obesity prevention: emerging examples, entrenched barriers, and new thinking. Lancet. 2015;385(9985):2400-9. In Brazil, population-based surveys indicate that overweight was present in 6% of children between 5 and 9 years in 1974-1975, rising steeply to 34.8% in 2008-2009.⁴4 Instituto Brasileiro de Geografia e Estatistica (IBGE). Pesquisa de orçamentos familiares 2008-2009: antropometria e estado nutricional de crianças, adolescentes e adultos no Brasil. Rio de Janeiro; 2010. Globally, overweight in children increased 47.1% over the past 20 years.⁵5 Ng M, Fleming T, Robinson M, Thomson B, Graetz N, Margono C, et al. Global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2014;384(9945):766-81. In 2010, it was estimated that overweight and obesity were responsible for 3.4 million deaths worldwide.⁶6 Lim SS, Vos T, Flaxman AD, Danaei G, Shibuya K, Adair-Rohani H, et al. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet. 2012;380(9859):2224-60. Chronic diseases remain a public health challenge in Brazil. The medical costs associated with diseases related to overweight and obesity are substantial in Brazil, reaching nearly US$ 2.1 billion annually.⁷7 Bahia L, Coutinho ES, Barufaldi LA, Abreu G de A, Malhao TA, de Souza CP, et al. The costs of overweight and obesity-related diseases in the Brazilian public health system: cross-sectional study. BMC Public Health. 2012;12:440.

Overweight in children and adolescents generates great concern because it is a risk factor for the development of hypertension, type 2 diabetes mellitus, dyslipidemia and other cardiovascular risk factors,⁸8 Pellanda LC, Echenique L, Barcellos LMA, Maccari J, Borges FK, Zen BL. Doença cardíaca isquêmica: a prevenção inicia durante a infância. J Pediatr (Rio J.). 2002;78(2):91-6.^,99 Cesa CC, Barbiero SM, Pellanda LC. Risco cardiovascular em crianças e adolescentes. Rev Soc Cardiol Estado do Rio Grande do Sul. 2010;18(20):1-6. which, if not prevented or treated at an early age, tend to persist during adulthood.¹⁰10 Craigie AM, Lake AA, Kelly SA, Adamson AJ, Mathers JC. Tracking of obesity-related behaviours from childhood to adulthood: A systematic review. Maturitas. 2011;70(3):266-84.

Nutritional intervention studies have shown a positive effect on preferences for healthy foods and a decrease in daily consumption of sugary drinks.¹¹11 Verstraeten R, Roberfroid D, Lachat C, Leroy JL, Holdsworth M, Maes L, et al. Effectiveness of preventive school-based obesity interventions in low- and middle-income countries: a systematic review. Am J Clin Nutr. 2012;96(2):415-38.^,1212 Vargas IC, Sichieri R, Sandre-Pereira G, Veiga GV. Avaliação de programa de prevenção de obesidade em adolescentes de escolas públicas. Rev Saúde Pública. 2011;45(1):59-68. Permanent changes in diet quality, energy intake and physical activity demand preventive actions.¹³13 Haslam DW, James WP. Obesity. Lancet. 2005;366(9492):1197-209. On that account, promotion of a healthy diet, physical activity, and monitoring of the nutritional status in childhood and adolescence are essential elements in public health. Being an educational environment that contributes to build personal values, schools become a key figure for health promotion and obesity interventions, bringing the development of critical awareness to the construction and modification of eating habits.¹⁴14 Oliveira CL, Fisberg M. Obesidade na infância e adolescência: uma verdadeira epidemia. Arq Bras Endocrinol Metabol. 2003;47(2):107-8.^,1515 Foltz JL, May AL, Belay B, Nihiser AJ, Dooyema CA, Blanck HM. Population-level intervention strategies and examples for obesity prevention in children. Annu Rev Nutr. 2012;32:391-415.

A number of international agencies, such as the Centers for Disease Control and Prevention (CDC) and the Institute of Medicine (IOM), launched campaigns with guidelines for health promotion in schools aiming to address the epidemic of obesity and its consequences.¹⁶16 Joint Committee on National Health Education Standards. National Health Education Standards: achieving excellence. 2nd ed. [Cited in 2016 Nov 10]. Available from: http://www.cdc.gov/healthyyouth/sher/standards/index.htm.
http://www.cdc.gov/healthyyouth/sher/sta...

17 American Heart Association. Teaching Gardens. [cited in 2013]. Available from: http://www.heart.org/HEARTORG/GettingHealthy/HealthierKids/TeachingGardens/Teaching-Gardens_UCM_436602_SubHomePage.jsp.
http://www.heart.org/HEARTORG/GettingHea... ^-1818 The National Academics of Sciences Engineering Medicine. Accelerating Progress in Obesity Prevention: Solving the Weight of the Nation. Washington DC:The National Academies Press;2012. In Brazil, the School Health Program is designed to promote the comprehensive health care of public school students and is structured in four blocks that seek to: assess health conditions; perform actions of prevention and promotion of health conditions; promote continuing education for professionals and the young; present evaluation and monitoring of health conditions of the students. The responsibility for planning and carrying out these actions is upon the primary care health team, and the objective is to integrate the educational system and the Brazilian Unified Health System (SUS).¹⁹19 Ministério da Saúde. Saúde na escola. Brasília , DF; 2009. (Cadernos de Atenção Básica, n.24). (Série A. Normas e Manuais Técnicos). However, this government action does not have coverage of all schools in the country yet.

In order to implement educational interventions in a large scale, it is important to adequately test their effectiveness. It is also important to look for simple and low-cost alternatives that can reach the largest possible number of schools. Improving the knowledge about food choices may be an important basis for children to acquire and maintain a healthy lifestyle from an early age, and possibly to sustain these healthy habits in subsequent stages of life.

Thus, the purpose of this study protocol is to evaluate the effectiveness of an intervention designed to improve knowledge of food choices in the school environment.

Methods

This protocol is reported according to the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) statement.

Study design

Overview

This is a cluster-randomized parallel two-arm study conducted in Brazil. The units of observation are individual children, and the units of randomization are schools. Randomization will be performed at the school level to avoid contamination. After the baseline assessment, enrolled schools are randomized to one of two study arms: the intervention arm focusing on changes in lifestyle, and the control group arm, that receives usual recommendations by the health care team. A summary of the study design, interventions and timelines is shown in Figure 1.

The primary outcome for the participants is change in body mass index (BMI = kg/m²), and the secondary outcomes are behaviors related to healthy eating, increased preferences for fruits and vegetables, increased physical activity and reduced screen time. The Institutional Research Ethics Committee approved the protocol for the study, which is registered in the Brazilian Registry of Clinical Trials, Register Number RBR-97bztb, and named “Intervention program for health promotion in schools of public elementary school in the state of Rio Grande do Sul: randomized clinical study”. The Universal Trial Number of this study is U1111-1155-7731.

Inclusion criteria

Children between the ages of 5 and 15 years, from both genders, enrolled in the public schools participating in this study, attending from the 1st to the 9th grades of the elementary and middle school will be eligible for the study (Table 1). The child and parent(s) or legal guardian(s) are required to sign the assent term and the informed consent.

Exclusion criteria

Children are excluded if they have conditions or other circumstances that could interfere with participation in the measurements or the interventions or if the parent does not give or is unable to give consent or the child does not assent. Participants are also excluded if they do not complete baseline assessments in 3 weeks.

Screening and recruitment

The screening and recruitment activities will be developed during the course of 4 weeks. During the first week, the school electronic files of student enrollment will be consulted to identify potential participants (the eligibility criteria can be seen in Table 1). During the following two weeks, recruitment letters will be sent to the student's guardians, with explanation of the study and attached Informed Consent Form. During the fourth week, individuals who agree to participate in the study will undergo anthropometric assessment, provided that there is no impediment for physical evaluation.

Randomization

Cluster randomization will be performed with distribution of two schools for the control group and two schools for the intervention group. A biostatistician who does not have direct contact with study participants will generate the random allocation sequences using a computerized random number generator. After the inclusion of each cluster, the allocation of that particular cluster will be provided to the study coordinator. Due to the characteristics of the intervention, it is not possible to mask participants or interventionists to group assignment. There will be no crossover between study arms, but the intervention will be offered to the control group at the end of the study, if proved to be effective.

Assessments

Measures are conducted at baseline (month one) and post-treatment (month 9).

Anthropometric measures

Weighing electronic scales with a maximum capacity of 150 kg and precision of 100 g, properly checked for tare weight, will be used for weight measures. The individual will be weighted barefoot and wearing light clothes. A metallic measuring tape with a capacity of 2 m/0.1 cm, set in an existing flat wall in the room, will be used to measure height, with the individual in the upright position, during maximum inspiration, barefoot and with empty pockets. These data will be used for the following calculation of BMI, obtained by weight, measured in kilograms, divided by the square of the height, measured in meters (kg/m²). That will be calculated and nutritional status will be classified, both using the Anthro Plus software, according to the reference of the World Health Organization (WHO) 2006/2007.

Dietary intake

The collection of dietary data, referring to the eating habits of the participants, will be assessed by a Food Frequency Questionnaire (FFQ),²⁰20 Fisberg RM, Marchioni DML (orgs). Manual de avaliação do consumo alimentar em estudos populacionais: a experiência do inquérito de saúde em São Paulo (ISA). São Paulo: Faculdade de Saúde Pública/USP; 2012. previously validated for the study population, designed to collect information on the frequency of food consumption and/or food groups for further association with other study variables, such as lifestyle and anthropometric measurements.

Physical activity

International Physical Activity Questionnaire (IPAQ)²¹21 Craig CL MA, Sjöström M, Bauman AE, Booth ML, Ainsworth BE, et al. International Physical Activity Questionnaire: 12-country reliability and validity. Med Sci Sports Exerc. 2003;35(8):1381-95.^,2222 Guedes DP, Lopes CC, Guedes JERP. Reprodutibilidade e validade do Questionário Internacional de Atividade Física em adolescentes. Rev Bras Med Esporte. 2005;11(2):e147-e154. will be used for all ages to classify the level of physical activity, in spite of the fact this instrument has being validated only for adults and adolescents, since there is not yet a validated questionnaire that can suit the needs of this study and adequately classify physical activity levels in Brazilian children.

Screen Time

Screen time refers to the amount of time individuals spend in front of television, video games and computer, and is considered to be a sedentary activity. It will be measured by hours per day and number of days in the week of screen time.

Knowledge of healthy habits

The acquisition of knowledge about healthy habits will be evaluated through a questionnaire validated for age,²³23 Cecchetto FH, Pellanda LC. Construção e validação de um questionário sobre conhecimento de hábitos saudáveis e fatores de risco para doenças cardiovasculares em estudantes. J Pediatr (Rio J.). 2014;90(4):415-9. consisted of knowledge about food and healthy activities in daily life.

Demographics measures

During baseline assessment, parents will be asked about a series of demographic data included in the Brazilian Economic Classification Criterion by the Brazilian Association of Research Companies,²⁴24 Associação Brasileira de Empresas de Pesquisa (ABEP). Critério de classificação econômica Brasil. [Citado em 2016 set 20]. Disponível em: http://www.abep.org.
http://www.abep.org... which includes: age; educational attainment of the family head; questions about household appliances and other family properties; street paving and treated water in the house.

Sample size

The sample size was calculated to detect a difference in 0.2 kg/m² on BMI, with a standard deviation of 0.05, statistical power of 90% and alpha error of 0.05. An estimate of mean 19 kg/m² is used as obtained from our pilot study. A number of 99 participants per group was estimated using these parameters. To compensate for losses, the sample size will be increased by 10%.

Planned data analyses

Collected data will be entered and analyzed using the Statistical Package for Social Sciences, version 17.0. Quantitative variables will be expressed as mean and standard deviation in the presence of normal distribution or median and interquartile range in the presence of asymmetric distribution. Qualitative variables are expressed as absolute and relative frequencies.

Adjusted analysis for primary and secondary outcomes will be performed using generalized estimating equations (GEE). The comparison between secondary outcomes will be performed using the nonparametric Wilcoxon test.

The level of significance for all tests will be 95% (α = 0.05) and will follow the intention to treat principle. P-values will be reported up to three decimal places with p-values < 0.005 reported as p < 0.005. The outcomes will be evaluated by a blind adjudicator.

Interventionists

The interventions in this study will be delivered by the nutritionists of the Children and Adolescents Cardiovascular Prevention Group (PREVINA),²⁵25 Grupo de Pesquisa em Prevenção Cardiovascular na Infância e Adolescência - PREVINA. Porto Alegre (RS): Departamento de Cardiologia Pediatrica Preventiva/ Instituto de Cardiologia do Rio Grande do Sul; 2016. nutrition graduate students and health professional contributors employed by the City Hall (psychologists, physical education teachers, nurses). All interventionists will undergo extensive training on: intervention protocol; overall intervention objectives, content and format; and specific instructions for each intervention session.

Intervention description

Intervention activities will occur monthly in the school multimedia room or sports court (Table 2). All activities will be offered in different school shifts and schedules so that all students in all classes can participate.

Usual care comparator

Participants randomized to the control group will not receive any guidance during the study. Children will receive the usual care and recommendations through the school and health authorities.

Should the intervention prove to be effective, at the end of the study, the institutions allocated to the control group will receive all intervention activities if they wish.

Discussion

This randomized clinical trial is intended to help filling a gap in the literature regarding simple, low-cost and effective interventions to deal with the epidemic of obesity and overweight in developing countries. Numerous studies show that overweight and obesity rates in the young in Latin America bring important economic and health consequences.²⁶26 Rivera JA, de Cossio TG, Pedraza LS, Aburto TC, Sanchez TG, Martorell R. Childhood and adolescent overweight and obesity in Latin America: a systematic review. Lancet Diabetes Endocrinol. 2014;2(4):321-32. In spite of the need for individual approaches for children who are already overweight or obese, the international consensus is that prevention is the most realistic approach and the best value for money.²⁷27 Onis Md. Preventing childhood overweight and obesity. J Pediatr. (Rio J.).2015;91(2):105-7. It is therefore necessary to develop preventive interventions that can reach a larger number of children.

Facilitators and barriers for the development of healthy habits should be considered when designing a childhood overweight program. Adaptation to local culture and reality should also be a concern. One of the most important challenges of this study will be changing the approach to nutrition and physical activity. On that account, we designed interventions that include parents, teachers and students aimed at creating a positive impact on the health of children and adolescents.

The young need appropriate information to make healthy choices and change their sedentary behavior, but their parents and teachers are not always prepared to give that information. Therefore, involvement of trained health professionals specialized in the field is necessary in order to adequately provide that information. Given that children are exposed to the environment we create for them and that in Brazil they usually spend about 25 hours a week in school, it is important to design actions that seek to improve the school environment and create a healthy growth strategy.

The study also has some limitations, that must be addressed in future work. First, there is a possibility of cross-contamination of participants in the two intervention arms, since both interventions are delivered in a small city. Second, the trial does not evaluate the pubertal maturation, whose changes may impact on the body composition in childhood and early adolescence, such as weight gain in girls and a decline of body fat in pubertal boys.

In conclusion, we have described the basic rationale and design of the ongoing Healthy School, Happy School cluster-randomized trial. The study intervention aims to increase the ingestion of fresh food, reduce excessive consumption of sugary and processed foods, and reduce the hours of sedentary activities. The purpose of starting the dietary intervention at this stage of life is to develop a knowledge that will enable for healthy choices, providing opportunities for a better future for this population.

References

Publication Dates

History