The Impact of an Intervention Taught by Trained Teachers on Childhood BMI z Score
Condition: Evidence of an Intervention on Childhood BMI z Score
Study type: Interventional

Summary: 
      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.
    

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).
    

Intervention name(s): Training teachers on healthier lifestyles
Intervention type(s): Other
Intervention description(s): 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.
Allocation: Randomized
Intervention model: Factorial Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Prevention
Keywords: BMI z-score; children; overweight; school-based intervention; trained teachers; fruit; vegetables; Low nutrition energy dense foods