The Impact of an Intervention Taught by Trained Teachers on Childhood BMI z Score

July 18, 2011 updated by: University of Minho

The purpose of this study is to assess the effects of a six months nutrition intervention, delivered and taught by classroom teachers with in-service nutrition training, on the prevention of overweight and obesity among children in grades 1 to 4.

In this randomized controlled trial, 464 children from seven elementary schools were allocated to a six months nutrition educational intervention by their own teachers or to standard care. Intervened teachers had 12 sessions of three hours each with the researchers throughout six months, according to the following topics: nutrition and healthy eating (sessions 1 to 4); the importance of drinking water (session 5); strategies to encourage fruits and vegetables consumption and to decrease high energy-density foods intake (sessions 6 to 8); strategies to increase physical activity (sessions 9 and 10); and healthy cooking activities (sessions 11 and 12). After each session, teachers were encouraged to develop activities in class that focused on the learned topics. Sociodemographic, anthropometric, dietary, and physical activity assessments were performed at baseline and the end of intervention.

We expect that fewer intervened children become overweight and the consumption of fruit and vegetables will be higher. In addition, we expect a less consumption of low-nutrition high dense foods.

We also expect to provide further support to decrease overweight epidemic, involving classroom teachers in a training intervention and making them dedicated interventionists.

Study Overview

Detailed Description

The prevalence of obesity continues to increase (Ogden et al., 2006) and is growing concerns in Portugal and in the world. As successful treatments have been elusive, the prevention should be considered a high priority. So, present efforts are being dedicated to develop and implement overweight and obesity prevention interventions (Gortmaker, et al, 1999; James, Tomas & Kerr, 2004), in the hope that multilevel approach, if occur early in childhood, may improve eating habits and physical activity and therefore, contribute to prevent or reverse this epidemic state.

In each school, previously trained persons performed anthropometric evaluation, using standardized procedures (WHO Expert Commitee 1995). Anthropometric measurements were performed in children with light indoor clothing and barefooted. Weight was measured in an electronic scale, with an error of ±100g (Seca, Model 703, Germany), and height was measured using a stadiometer, with the head in the Frankfort plane. BMI was computed as mass, Kg/height, m2. The prevalence of underweight, normal weight, overweight and obesity was calculated according to the International Obesity Task Force (IOTF) criteria, making a correspondence between the traditional adult cut-off and specific values for children according to gender and age (Cole et al. 2000). A z-score (the number of standard deviations (SD) from the reference population) was calculated for each child using the LMS method and the calculation was determined using the LMS growth add-in for excel (Pan and Cole 2009).

Dietary intake was gathered by 24h dietary recalls obtained by nutritionists and/or trained interviewers. We assessed a single recall before and another after the intervention. The respondents had no prior notification of when the recalls would occur. Training of interviewers included practice using photos and food models to quantify portion sizes, experience in probing information from children without suggesting responses as well as the type of food consumed in detail of fat content, brand name, constituents of mixed dishes and so on. The 24h dietary recall is the most commonly used dietary assessment method because it is easy to administer, can be performed in large-scale studies (Kranz and Sie-Riz 2002, Gomez-Martínez et al. 2009), and can be used to assess adequacy of energy and macronutrient intakes. During the 24h dietary recall, each child was asked to recall all food and beverages consumed during the past 24h. Daily routines were used as prompts (waking up, going to bed, time between classes, and before or after school) to enhance recall. Portion sizes of foods and beverages consumed were also estimated using food models, photos and other props (cups, glasses, food wrappers or containers) as an aid in determining serving sizes. Energy and nutritional intake were estimated using an adapted Portuguese version of the nutritional analysis software Food Processor Plus (ESHA Research Inc., Salem, OR, USA). The 24-hour dietary recall interviews captured the time and name of each eating occasion, the foods and beverages reported at each eating occasion, and the source from which item was obtained.

In order to assess the level of physical activity of children, parents were asked five questions with four answer choices (4-point scale) ranging from 0 (very seldom) to 4 (very often): a) Outside the school does your child take part in organized sport? b) Outside school does your child take part in non-organized sport? c) Outside school, how many times a week does your child take part in sport or physical activity for at least 20 minutes? d) Outside school hours, how many hours a week does your child usually take part in physical activity so much that he gets out of breath or sweat? e) Does your child take part in competitive sport? (Mota and Esculcas 2002). The total sum of the points was computed reaching a maximum of 20 points. To express the activity levels, a Physical Activity Index was obtained, which divided the sample into four activity classes: sedentary group (0-5); low activity group (6-10); moderately active group (11-15); and vigorously active group (16-20), on the basis of their reported physical activity (Mota and Esculcas 2002).

Social, demographic and family characteristics were assessed by questionnaire. The survey sent to parents contained questions about gender and age of children, education of the parents (recorded in five categories: 0, 1-4, 5-9, 10-12, and more than 12 years of formal education). This information was further grouped for analysis into three categories: up to 9 years, 10-12 years, and more than 12 years of education.

The research team proposed, in January 2008, the accreditation of the sessions that were developed with the teachers to the Minister of Education, Scientific-Pedagogic Council for In-service Training (Conselho Científico Pedagógico da Formação Contínua, Ministério da Educação). This proposal was approved in September 2008 in the form of "training workshop" with 72 hours duration, distributed by active learning strategies (36 hours) and work contact with the children (36 hours). Teachers of the intervention group had 12 sessions of three hours each with the researchers throughout six months, which included the following topics: nutrition and healthy eating for the children and the families (sessions 1 to 4); the importance of the water (session 5); strategies to encourage fruits and vegetables consumption and to decrease high energy density foods intake (sessions 6 to 8); to increase physical activity and to reduce screen time exposure (sessions 9 and 10); and healthy cooking (sessions 11 and 12). After each session, teachers resend the learned contents to develop creative and engaging classroom activities about the addressed topic. All the questions that arose during the implementation of classroom activities were addressed and resolved shortly with the researchers. Teachers were allowed to develop and refine the activities and learning strategies that were proposed by researchers. At the end of this period, the teachers delivered a critical report of activities focused on the work contact with children.

The data analysis was performed using SPSS ®, Version 18.0 (SPSS Inc; Chicago, IL).

Study Type

Interventional

Enrollment (Actual)

464

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Braga
      • Guimarães, Braga, Portugal, 4810
        • Santos Simões group of schools

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

5 years to 12 years (CHILD)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Children from the schools involved in the study with informed consent provided by parents.

Exclusion Criteria:

  • Age more than 12

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: PREVENTION
  • Allocation: RANDOMIZED
  • Interventional Model: FACTORIAL
  • Masking: DOUBLE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Lifestyle counseling
During 2007/2008 seven out of eighty public elementary public schools from Guimarães (Portugal) were invited to participate in this study. The number of schools involved was according to constraints of personnel for the assessment and intervention. Schools were the unit of randomization and three were assigned into intervention, and four into control group. Data was collected prior to intervention and immediately after, during the year 2009 (post-intervention). Prior to participation on data collection, parents provided informed consent, and children provided oral assent.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
BMI z score
Time Frame: the first 3 months after the intervention
the first 3 months after the intervention

Secondary Outcome Measures

Outcome Measure
Time Frame
dietary intake
Time Frame: within the first 3 months after the intervention
within the first 3 months after the intervention

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Study Director: Pedro Moreira, PhD, Universidade do Porto
  • Study Director: Beatriz Pereira, PhD, University of Minho
  • Principal Investigator: Rafaela V Rosario, University of Minho

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2007

Primary Completion (Actual)

June 1, 2008

Study Completion (Actual)

June 1, 2009

Study Registration Dates

First Submitted

June 28, 2011

First Submitted That Met QC Criteria

July 18, 2011

First Posted (Estimate)

July 19, 2011

Study Record Updates

Last Update Posted (Estimate)

July 19, 2011

Last Update Submitted That Met QC Criteria

July 18, 2011

Last Verified

July 1, 2011

More Information

Terms related to this study

Other Study ID Numbers

  • 1845
  • 7613/2008 (Other Identifier: Portuguese Data Protection Authority)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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