Effectiveness of the Numerous Educational Strategy Interventions Seeking to Increase the Percentage of Water Consumed Among Early Elementary School Students With a 1-year Follow up
Phase: NA
Conditions: Water Consumption, Healthy Lifestyle, Elementary School
Sponsor: Jose Francisco Gonzalez-Zamora

Pimentel-Hernández C et al. Version 1.0.  Date  April 19 th 2017 
 
 
 
 
National Autonomous University of Mexico 
Master's and Doctoral Program in Medical, Dental and Health Sciences 
FIELD OF KNOWLEDGE 
Medical Sciences 
Effectiveness of the numerous educational strategy interventions seeking to increase the 
percentage of water consumed among early elementary school students with a 1-year 
follow up 
Student 
Claudia Pimentel Hernández 
Tutor 
José Francisco González Zamora 
Tutorial Committee 
José Luis Arredondo García 
Silvestre García De la Puente 
Carlos Polanco González 
Carlos Jiménez Gutiérrez 
 
 
 

Pimentel-Hernández C et al. Version 1.0.  Date  April 19 th 2017 
 
 
GENERAL INDEX 
1.0 SUMMARY……………………………………………………………………………………………………………………………….... 3 
2.0 RESEARCH QUESTION ………………………………………………………………………………………………………………….4 
3.0 INTRODUCTION…………………………………………………………………………………………………………………………….4 
4.0 THEORETICAL FRAMEWORK …………………………………………………………………………………………………………5 
4.1 WHO Global Action Plan for the Prevention and Control of Non-communicable Diseases …………..5 
4.2 National Strategy for the Prevention and Control of Overweight, Obesity, and Diabetes …………....6 
4.3 National Development Plan 2013-2018 ……………………………………………………………………………………….7 
4.4 General Guidelines for the Sale or Distribution of Food and Beverages in Cafeterias of Elementary 
Schools ………………………………………………………………………………………………………………………….………………8 
4.5 Educational Strategy "I Prefer Plain Water"…………………………….……………………………………………………8 
4.5.1 Pedagogical support of the educational strategy "I Prefer Plain Water" ……………………… …………..9 
4.5.2 Effectiveness of the educational strategy "I Prefer Plain Water" …………………………………………….11 
5.0 DESCRIPTION OF THE PROBLEM ………………………………………………………………………………………………..13 
6.0 JUSTIFICATION …………………………………………………………………………………………………………………………..13 
7.0 GENERAL OBJETIVES……………..………………………………………………………………………………………..………….13 
7.1 Primary Objetive …………………:……………………………………………………………………………………….……………13 
7.2 Secondary Objetive  …………………………………………………………………………………………………….…………….14 
8.0 HYPOTHESIS ……………………………………………………………………………………………………………………………… 14 
9.0 STUDY DESIGN …………………………………………………………………………………………………………………….…….14 
10.0 POPULATION ……………………………………………………………………………………………………………………………14 
10.1 Target Population …………………………………………………………………………………………………………………….14 
10.2 Eligible Population ……………………………………………………………………………………………………………………14 
11.0 SELECTION CRITERIA……………………………………………………………………………………………………………….. 14 
11.1 Inclusion Criteria ……………………………………………………………………………………………………………………..14 
11.2 Exclusion Criteria ……………………………………………………………………………………………………………………..15 
11.3 Elimination Criteria ………………………………………………………………………………………………………………….15 
12.0 MATERIAL AND METHODS ………………………………………………………………………………………………….……15 
12.1 Human Resources for the Preparation of the Study……………………..…………………………………………..15 
12.2 Material Resources for the Preparation of the Study………………………………………………………………..15 
12.3 Site and Participants ………………………………………………………………………………………………………………..16 
12.4 Intervention …………………………………………………………………………………………………………………………….16 
12.5 Evaluation Process …………………………………………………………………………………………………………………..17 
12.6 Measurement Instruments …………………………………………………………………………………….………………..18 
13.0 SAMPLE SIZE …………………………………………………………………………………………………………………………….19 
14.0 STUDY VARIABLES ……………………………………………………………………………………………………………………21 
15.0 STATISTICAL ANALYSIS ……………………………………………………………………………………………………………..22 
16.0 ETHICAL CONSIDERATIONS……………………………………………………………………………………………………… 22 
17.0 BIBLIOGRAPHY …………………………………………………………………………………………………………………………23 
 

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1.0 SUMMARY 
Introduction. The incidences of overweight and obesity among children in Mexico have 
increased at alarming rates over the past three decades, partially because of the increased 
intake of sugary beverages that have a high caloric content and low nutritional status. The 
Mexican government identified the promotion of water consumption as a major strategy 
to reduce the energy density of diets and thus at least partially prevent the problems of 
overweight, obesity, and other diseases associated with the excessive intake of sugary 
beverages. Therefore, the primary objective of the National Agreement for Nutritional 
Health (ANSA, in Spanish) sought to increase water intake and discourage the 
consumption of sugary beverages among the population. Schools are optimal locations to 
conduct healthy lifestyle intervention programs aimed at children to increase water 
consumption and consequently help reduce childhood obesity. To this end, the education 
strategy "I Prefer Plain Water" was designed. This strategy proved to effectively increase 
water consumption and reduce the consumption of sugary beverages in the short term; 
however, its ability to sustain the same pattern with regard to overall liquid consumption 
has not been established over the long term. 
Objective. The current project seeks to evaluate the effectiveness of numerous 
educational strategy interventions to increase the percentage of water consumed among 
early elementary school students over a 1-year period. 
Material and methods. A community intervention trial will be conducted at four public 
elementary schools of the Coyoacán Delegation in Mexico City. It will include healthy first 
graders during the 2017-2018 school year whose parents agree to participate through 
verbal informed consent and a signed privacy notice. These parents will complete a 
baseline 3-day beverage record (two weekdays and one weekend day). The four schools 
will be assigned to one of three groups: Group I will receive the educational strategy 
during the first grade; Group II will receive it during first and second grades; and Group III 
will receive it during the first, second, and third grades. All schools will have water 
dispensers inside the classrooms, and the children will receive a reusable 600-mL bottle so 
they are able to consume water on demand throughout the day. A second record of 
beverage consumption will be obtained by completing multiple interventions within each 
group, and a third record will be completed 1 year later.   
Statistical analyses. Descriptive statistics will be used to summarize the numerical 
variables with medians, minimums, and maximums. The Kruskal-Wallis test will be applied 
to compare the baseline intake of beverages among the three groups. In each group, 
baseline water consumption will be compared with that 1 year after the end of the 
interventions using the Wilcoxon test. 
Ethical Considerations. This research is considered to have minimal risk; thus, the 
Research Ethics Committee will be asked to approve a request for verbal informed 
consent, and the parents will be asked to sign a privacy notice. The general health law for 
research in Mexico will be respected, and ethical clinical practices will be followed. The 
authors have no conflicts of interest to declare. 
 

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2.0 RESEARCH QUESTION 
Does the number of educational strategy interventions aimed at early elementary school 
children increase the percentage of water consumed after a 1-year follow up? 
 
3.0 INTRODUCTION 
In Mexico, the prevalence of overweight and obesity has increased among children at an 
alarming rate over the past three decades, partially because of the increased intake of 
sugary beverages that have high caloric content and low nutritional status. The major 
types of beverages that provide the most energy intake are soft drinks, beverages made 
from fruit juice (with or without added sugar), flavored water, and natural juices added 
with sugar and whole milk. 
Energy consumption from these beverages doubled for all age groups from 1999 to 2012; 
when added to the energy obtained from food in the diet, these drinks contributed to an 
excessive intake of energy linked to the development of obesity. 
The Mexican government identified the promotion of water consumption as a major 
strategy to reduce the energy density of the diet and thus at least partially prevent the 
problems of overweight, obesity, and other diseases associated with the excessive intake 
of sugary beverages. Therefore, the National Agreement for Nutritional Health (ANSA, in 
Spanish) considers increasing the intake of water and discouraging the consumption of 
sugary beverages as priorities for this population. 
Given the evidence that school provides an optimal environment to conduct nutritional 
promotion programs that encourage the practice of healthy lifestyles that include the 
promotion of water consumption, a need arose to create such an educational strategy. 
Ogali (Nutrition Consulting Company: www.ogali.com) designed the educational strategy “I 
Prefer Plain Water”, and it demonstrated short-term effectiveness by increasing the 
consumption of water and reducing the consumption of sugary beverages and soft drinks. 
However, it is unknown whether these observed changes are sustainable throughout early 
elementary education, a period that education specialists have established as essential to 
forming healthy habits for life. 
Evaluating the long-term (1-year) effectiveness of this program is necessary because the 
knowledge gained will help determine the number of interventions that children should 
receive to maintain a healthy water-consumption pattern to establish public health 
policies that allow children to maintain a healthy lifestyle that affects their quality of life. 
P 
Public early elementary school students 
I 
Educational strategy 
C 
Number of educational interventions 
O 
Increase in the percentage of water consumed over the long term 

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4.0 THEORETICAL FRAMEWORK 
 
4.1 World Health Organization (WHO) Global Action Plan for the Prevention and Control 
of Non-communicable Diseases 
From January 28 to February 1, 2002, a convention assembling experts in food, nutrition, 
and the prevention of chronic diseases was held in Geneva that included the participation 
of the WHO and the Food and Agriculture Organization of the United Nations (FAO). This 
convention continued the work of a WHO study group on diet, nutrition, and the 
prevention of non-communicable diseases that met in 1989 to make recommendations 
for the prevention of chronic diseases and the reduction of their effects (1). 
The convention recognized that the growing epidemic of chronic diseases that affects 
both developed and developing countries is related to changes in dietary habits and 
lifestyles. Participants examined the considerable scientific progress made in different 
areas. For example, better epidemiological data now exist for determining risk factors in 
certain areas, and the results from controlled clinical trials are available. The mechanisms 
that lead to chronic diseases are clearer, and interventions that reduce risk exist. 
Furthermore, specific food components that increase the likelihoods of these diseases and 
appropriate interventions to modify their effects have been identified. 
Consultations provided opportunities for the WHO and FAO to use the latest available 
scientific data and update their recommendations of action to governments, international 
agencies, and relevant public and private sector partners. The overall objective of these 
recommendations was to implement more effective and sustainable policies and 
strategies to address the growing public health challenges related to diet and health. 
To achieve the best chronic disease prevention results, the strategies and policies applied 
must fully recognize the paramount relevance of diet, nutrition, and physical activity. This 
briefing calls for a change in the conceptual framework. 
Diet and nutrition are important to promote and preserve good health throughout life. Its 
role as determinant of chronic non-communicable diseases is well established, making it a 
key component of prevention activities (1). 
A high intake of free sugars undermines the nutritional quality of the diet because it 
provides a considerable amount of energy but lacks certain nutrients. The consultation 
considered that the restriction of free sugars most likely also contributes to reducing the 
risk of overweight. The working group noted the following: 
Free sugars. Drinks abundant in free sugars increase total energy intake by reducing 
appetite control. Thus, the compensatory reduction of food intake is lower after 
consuming sugary beverages than that when other foods of equivalent energy content are 
consumed (2,3,4,5). A recent randomized clinical trial showed that soft drinks rich in free 
sugars are associated with a higher consumption of energy and a progressive increase in 

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body weight compared with calorie-free beverages with artificial sweeteners (6). Children 
who consume many soft drinks rich in free sugars are at greater risks of overweight and 
obesity (5). The consultation admitted that the goal of the population consuming less than 
10% of its total energy in the form of free sugars would be difficult to meet. However, 
studies that show that free sugars do not influence excess weight have limitations. The 
CARMEN study was a randomized multicenter trial on the management of carbohydrate 
ratios in European national diets that analyzed the effects of altering the ratio between 
fats and carbohydrates as well as the relationship between simple carbohydrates and 
complex carbohydrates on the body weights and blood lipid levels of people with obesity. 
A greater weight reduction was associated with diets rich in complex carbohydrates than 
those rich in simple carbohydrates. 
More information is available on the effects of the school environment on nutritional 
knowledge, dietary guidelines, and physical activity at school as well as sedentary habits at 
home. Some studies (7) have shown that school-based interventions affect the prevention 
of obesity; however, additional studies are clearly needed to provide more data about 
both aspects. 
High intake of sugary drinks (causal factor). Low-fat diets are proportionally richer in 
carbohydrates (with varying amounts of sugars) and protect against harmful weight gain; 
however, a high intake of free sugars in beverages most likely promotes weight gain. The 
physiological effects of caloric intake on satiety and the satiation process appear to differ 
depending on the energy contained in solid foods or liquids. Perhaps because of reduced 
gastric distension and greater speed of transit, the energy contained in liquids is poorly 
"detected" by the body, and the subsequent ingestion of solid food is not adjusted for 
properly (8). Data from cross-sectional and longitudinal studies support this assertion 
(9,10,11). The high and increasing intake of sugary beverages among children in many 
countries is worrying. Each new can or glass of sugary beverage consumed per day is 
estimated to increase the risk of obesity by 60% (8). Most of the extant data concern soft 
drinks; however, many fruit and concentrate drinks are equally energy-rich and promote 
weight gain when consumed in large quantities. Overall, evidence of the contribution of 
the high intake of sugary beverages to weight gain is considered moderately strong. 
4.2 National Strategy for the Prevention and Control of Overweight, Obesity, and 
Diabetes 
Mexico has one of the highest consumption rates of soft drinks and sugary beverages. 
According to the results of the national health surveys conducted from 1999 to 2006, the 
number of households that consumed bottled soft drinks increased from 48% to 60% 
during that period. Moreover, the 2008 School Health Survey placed soft drinks among the 
five most consumed products in public elementary and middle schools in the country. In 
contrast, the results of a study conducted by the National Institute of Public Health of 
Mexico revealed that children reported only 28.1% of their total liquid consumption was 
composed of water or water infusions without caffeine or sugar, whereas 44% was 

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composed of high-calorie beverages such as sweetened drinks with or without 
carbonation, flavored water, sweetened fruit drinks, and nectars (12). 
Certain non-communicable diseases are closely related to excess body weight (i.e., 
overweight and obesity). This situation is recognized as one of the most important public 
health challenges in the world given its magnitude, speed of increase, and the negative 
effect it has on the health of the people who suffer from it because it significantly 
increases the risk of non-communicable diseases (12). 
As part of the commemoration of World Health Day on April 2, 2013, President Enrique 
Peña Nieto implemented the National Strategy for Prevention and Control of Overweight, 
Obesity, and Diabetes when he defined the steps that the Ministry of Health must follow 
in a specific and clear way: "Finally, the third priority [is] prevention. Anticipating disease 
and avoiding its causes is the best way to take care of [one’s] health. In this sense, one of 
the most important prevention actions will be aimed at reducing obesity and overweight 
because [they] have become one of the greatest threats to the health of all Mexicans. This 
strategy should include the promotion of healthy lifestyles and eating habits, the 
generation and rescue of spaces for physical activity, the training of health personnel, and 
the strengthening of primary healthcare. To address obesity and diabetes, we will take the 
most effective measures according to [the] available scientific evidence, [thereby] 
prioritizing health above any other consideration. Government actions are important but 
will never be enough without the self-care of Mexicans" (13). 
4.3 National Development Plan 2013-2018 
Among elementary school-age children (5 to 11 years old), the rates of overweight and 
obesity are 19.8 and 14.6%, respectively. Based on reports from ENSANUT (National 
Health and Nutrition Survey) 2012, diabetes mellitus currently affects 9.2% of the 
country's population — an increase of 2.2% since 2006. Given its role as a cause of 
disease, obesity increases demands for health services and affects the economic and 
social development of the population. According to estimates from the National 
Autonomous University of Mexico (UNAM), the cost of obesity was 67 billion pesos in 
2008. If no actions are taken, then the future cost will be greater than the investment 
required today to implement the policies needed to address this problem. 
Three factors negatively affect the capacity of Mexico to fully enforce the right to health 
and therefore merit attention. First, the model with which the institutions of the sector 
were conceived is focused on cure rather than prevention. Second, policies have not been 
implemented with a multidisciplinary or interinstitutional approach regarding the 
improvement of the quality of health services. In this sense, confronting the diversity of 
the habits and customs of the population in matters of knowledge and healthcare become 
a challenge. Third, the current governing and structural arrangement in which the 
participation of vertically integrated and fragmented institutions prevails limits the 
operational capacity and cost effectiveness of the Public Health System (14). 
 

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4.4 General Guidelines for the Sale and Distribution of Food and Beverages in 
Elementary School Cafeterias 
 
In the Official Gazette of the Federation published on August 23, 2010, an agreement 
established the general guidelines for the sale and distribution of food and beverages for 
consumption in elementary school cafeterias. This document aimed to "establish actions 
that promote healthy diets and environments as well as promote a culture of eating habits 
that favors the adoption of an appropriate diet to prevent overweight and obesity”. This 
agreement included an appendix describing the nutritional characteristics of the type of 
foods and beverages that enable appropriate nutrition based on NOM-043-SSA2-2005, 
which includes prepared and processed foods, promotes the consumption of vegetables, 
fruits, and water on demand (15). 
Article 2. For the purposes of this regulation, water is defined as a liquid containing no 
physical, chemical, or biological contaminants; it is colorless, tasteless, and odorless, and it 
does not cause harmful effects to humans. Water is the most recommended liquid for 
adequate hydration because no nutrients or ingredients have been added (15). 
 
Chapter Thirteen of Prohibitions and Sanctions – Article 37 
The preparation, sale, and distribution of foods and beverages that (by representing a 
source of simple sugars, refined flours, fats, or sodium) do not comply with the nutritional 
criteria of the appendix of this regulation and, consequently, do not favor the health of 
students, thereby placing them at risk, are forbidden in schools within the Federal 
Educational Subsystem (15). 
Criteria used for snacks offered at public and private schools of the National Educational 
System 
Snacks, as part of the diets of schoolchildren, should provide necessary nutrients and 
energy between meals to avoid fasting times of more than 4 hours as well as to maintain 
satiety. It is recommended that school snacks cover 15% of the daily recommendations for 
energy and nutrients. School snacks should consist of vegetables and fruits, whole grains, 
oilseeds and legumes, and potable water on demand (15). 
The main objective in relation to beverages is to promote the consumption of water; thus, 
its availability must be ensured before any other drink. It is important to exclusively 
promote water consumption over the consumption of other types of beverages (15). 
4.5 The Educational Strategy "I Prefer Plain Water" 
The educational strategy “I Prefer Plain Water” was designed based on all of the above 
and given the scientific evidence showing that school is the optimal place to conduct 
healthy lifestyle intervention programs aimed at children (16), including increasing water 
consumption. Ogali Nutrition Consulting Company (www.ogali.com) elaborated this 
strategy that assembled a group of experts in research, public health, pedagogy, nutrition, 

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music, design, communication, social sciences, statistics, and design evaluation. The 
strategy is ludic and based on a collaborative scheme in which the students, teacher, and 
the family participate. This strategy consists of four educational sessions, with a duration 
of approximately 60 minutes each, which must be given every 2 weeks. The program and 
educational materials are specifically designed for first, second, and third graders. 
4.5.1 Pedagogical support of the educational strategy "I Prefer Plain Water" 
The educational strategy “I Prefer Plain Water” was designed based on the postulates of 
three theories of knowledge that have proved useful in behavior modification and the 
development of life skills, which together lead children to build a permanent foundation 
to acquire healthy lifestyles. 
The first theory is social cognitive and exposes individuals to the acquisition of knowledge, 
rules, skills, habits, and strategies by observing others and socializing and interacting with 
the environment. Here, the individual modifies his or her behavior by observation and 
modeling. In turn, the individual influences other members of the social environment. 
Albert Bandura, lead proponent of this position, argued that it is necessary to identify the 
influences that explain why and how a behavior is conducted to modify it. These 
influences are known as “determinants” or “mediators” of behavior. 
This strategy uses five mediators to modify behaviors: 
Expected results. The strategy enables students to easily visualize the benefits (expected 
results) that will be gained by simply increasing water consumption through characters in 
vignettes, posters, and an exchange of knowledge and experiences within the group. 
Behavioral capacity. In each educational session, children set a feasible water-
consumption goal, monitor themselves for the prescribed time, and acknowledge their 
progress. They are recognized for their effort, thereby demonstrating that they can adopt 
the desired behavior (behavioral change of an increase in water consumption). 
Modeling and learning by observation. This strategy’s core point is the example of the 
teacher modeling water consumption at different times. Moreover, children can be peer 
models for each another. 
Self-efficacy. This strategy offers students frequent opportunities to drink water and prove 
to themselves that they are able to change their habits with regard to the expected 
behavior. Self-efficacy represents a way for them to evaluate whether they are properly 
hydrated through observing the color of their urine. 
Reinforcements. At each session, the students' achievements are recognized as they 
approach or meet the set goal; strategies are shared, and participants are encouraged to 
continue. Commitments are also made within the social circles where they belong, 
enabling them to strengthen their behavior in personal (strengthening self-esteem and 
self-care), group, and family situations. 

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The second theory is that of social constructivism posed by Vygotsky, which takes the idea 
that people construct their knowledge not only via the subject-object relationship but also 
via a subject-mediator-object triad (i.e., through social interactions with others and the 
influence of the culture in which they live). Therefore, the classroom activities are not 
individual but group activities. In addition, through the tasks that are conducted in each 
session, family members become involved to affect the culture in which they live to 
promote healthy environments. 
Ausubel's theory of meaningful learning states that to promote permanent modification, it 
is necessary to appeal to intrinsic motivation and meaningful learning based on close 
situations and the actual needs and interests of children. Therefore, the strategy seeks to 
have children identify with one of the characters in vignettes and associate the issues 
presented to them with their own reality. In addition, songs and games are used to 
playfully assimilate important concepts that strengthen healthy behaviors. 
Following the principles of competency learning, the strategy starts from the knowledge, 
skills, and attitudes presented in children and seeks to enhance them for use as tools that 
allow them to face problems related to healthcare more effectively in everyday life. Some 
of the competencies mentioned in the document “Competences for primary education 
SEP”, which are referenced in activities and games, include the capacity for expression 
through language, decision making, problem solving, individual responsibility, the 
development of self-esteem, teamwork, the promotion of a culture of prevention, and 
healthcare and environmental protection. 
The third theory is that of Multiple Intelligences. Through his theory, Howard Gardner 
mentions that the world can be perceived via multiple ways of knowing, processing, 
representing, and communicating information (e.g., with images, words, numbers, body 
motion, rhythm, and music) as well as being in tune with oneself, with others, and with 
nature. 
Gardner proposes a pluralistic view of the mind and a multifaceted view of intelligence. 
His pluralistic view of the mind recognizes that many different facets of knowledge exist 
and views people as possessing different cognitive potentials that lead to different styles 
of knowing. 
His vision considers intelligence as not singular; all people have a wide range of 
intelligences, i.e., a repertoire of capacities necessary to solve problems. 
Finally, this view takes a globalizing approach through which the contents of different 
subjects are reinforced and aligned with the plans and policies of the Ministry of Public 
Education of Mexico (SEP). 
 
 
 

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4.5.2 Effectiveness of the educational strategy “I Prefer Plain Water” 
A previous study evaluated the effectiveness of the educational strategy to increase water 
consumption of first, second, and third graders in Mexico City. For this purpose, a 
community intervention test was conducted across eight elementary schools in the 
Coyoacán Delegation during the 2014-2015 school year. A 3-day beverage consumption 
record (two weekdays and one weekend day) was obtained from all participants. All 
schools were provided with water bottles inside the classrooms, and the children received 
a reusable 600-mL bottle. The schools were randomly assigned to an educational 
intervention group (IG) or a control group (CG). The IG had the educational strategy 
applied. At the end of the educational session cycle 4 months after baseline, a second 
record of beverage consumption was obtained, and a third was obtained at the end of the 
school year (4 months after the second). The strategy was considered effective if the 
students increased their water consumption by more than 220 mL. 
For the analysis, 777 of the 1,105 children included were considered: 413/986 in the IG 
and 364/762 in the CG with a median age of 7.1 years (range 5.6 to 9.4 years). The 
children for whom the record of drinks was obtained at all three times were analyzed. 
From the baseline record to the end (8 months), the IG median increase in water 
consumption was 167 mL (P < 0.001) compared with the CG, which increased 37 mL. The 
educational strategy was effective for 166/413 of the children in the IG compared with 
95/364 of the children in the CG (P < 0.001). The IG showed an 80 mL increase in their 
median total liquid consumption from baseline to first record and a 41 mL increase from 
the baseline record to the final record. In comparison, the CG increased 33 and 38 mL, 
respectively. These changes were not significant between the two groups but were 
significant within the IG from baseline to the first record. Significant differences were 
found with regard to the consumption of sugary beverages between groups (P = 0.027). 
The IG decreased 42 mL (16.8%), and the CG decreased 36 mL (14.6%) from baseline to 
the final record. Regarding the consumption of soft drinks, the IG decreased the 
consumption from 41 mL to 0 mL, whereas the CG reduced from 83 to 33 mL from 
baseline to the final record (P < 0.001). Figure 1 shows the change in beverage 
consumption in the groups at all three times. 
After water, dairy drinks were consumed most often, with a similar median for both 
groups throughout the trial (i.e., no significant differences). The consumption of hot 
drinks, soft drinks, and functional beverages was low and did not significantly change 
throughout the trial. 
 
 
 
 

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Figure 1. Change in beverage consumption, Intervention Group (IG) vs Control Group (CG) 
 
* Friedman related samples 
 
The “I Prefer Plain Water” educational strategy effectively increased the consumption of 
water and reduced the consumption of sugary beverages and soft drinks when evaluated 
over the short term (4 months after its implementation); however, its long-term 
effectiveness (1 year later) has not been established. 
According to the transtheoric model that uses the stages of change to integrate the 
processes and principles of change through the main theories of intervention, the 
maintenance stage in which the change in behavior persists occurs when the behavior is 
maintained for 6 months or more (17). Based on this idea, the effectiveness of this 
educational strategy will be evaluated 1 year after the intervention. 
 
Baseline 
Time 1 
Final 
Water 
Total liquids 
Sugary beverages 
Soft drinks 
GI 
CG 
GI 
CG 
CG 
IG 
IG 
CG 

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5.0 DESCRIPTION OF THE PROBLEM  
Obesity prevention in young children should be considered a matter of the highest priority 
because it is necessary to promote healthy lifestyle behaviors that include (among others) 
an increased consumption of water and a decreased consumption of sugary drinks. 
Studies have shown that school-based interventions affect obesity prevention. To date, 
educational strategies that promote adequate water consumption have been proposed as 
short-term strategies. Evidence exists of the need to reinforce these programs so that 
children continue with their acquired habits. 
The educational strategy "I prefer plain water" favorably modifies water consumption 
when evaluated in the short-term; however, whether this observed change is maintained 
throughout early elementary education, a period that education specialists have 
established as essential to sustain healthy habits throughout life, is unknown. 
 
6.0 JUSTIFICATION 
The Mexican government identified the promotion of water consumption as a major 
strategy to reduce the energy density of the diet and thereby help prevent the problems 
of overweight, obesity, and other diseases associated with the excessive intake of sugary 
beverages. Thus, the National Agreement for Nutritional Health (ANSA) considers 
increasing the intake of water and discouraging the consumption of sugary beverages as a 
priority with regard to the population. 
The educational strategy “I Prefer Plain Water” favorably affected water consumption and 
decreased the consumption of sugary beverages and soft drinks among early elementary 
school children in Mexico City when evaluated over the short term. The study of its long-
term effectiveness is necessary to establish public health policies that maintain healthy 
lifestyles over time to enhance the quality of life of the population. 
 
7.0 GENERAL OBJECTIVES 
This proposal seeks to evaluate the effectiveness of the number of educational strategy 
interventions to increase the percentage of water consumed among early elementary 
school students over a 1-year follow-up period. 
7.1 Primary Objective  
This study seeks to compare the percentage of water consumed among early elementary 
school children receiving one, two, or three interventions of the educational strategy “I 
Prefer Plain Water” at a 1-year follow-up evaluation. 
 

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7.2 Secondary Objective  
This study seeks to compare the monthly water consumption of participating schools 
during the follow-up period. 
This study seeks to describe the annual body mass index (BMI) of the participating 
students during the follow-up period. 
 
8.0 HYPOTHESES 
The percentage of water consumed will be greater in the group of children who will 
receive all three interventions. 
  
9.0 STUDY DESIGN 
Experimental, analytical, longitudinal, and prospective designs will be employed. The 
assignment will be conducted by each school. 
Community Intervention Test 
 
10.0 POPULATION 
10.1 Target Population 
Children who attend elementary public schools of the Coyoacán Delegation are the target 
population. 
10.2 Eligible Population 
First graders attending public elementary schools under the epidemiological surveillance 
of the Ajusco and Santa Úrsula Health Centers will be recruited during the 2017-2018 
school year. 
 
11.0 SELECTION CRITERIA 
11.1 Inclusion Criteria 
 Healthy children (according to the investigator) 
 Both girls and boys 
 Children whose parents agree to participation in the study through verbal 
informed consent 
 Children whose parents sign a privacy notice 

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11.2 Exclusion Criteria 
 Children who present with any pathology that interferes with the free 
consumption of water or with the proper execution of the study 
 Children for whom it is not possible to obtain a baseline record of beverage 
consumption 
 
11.3 Elimination Criteria 
 Children who do not attend more than two educational sessions within each grade 
level 
 Children with incomplete or improperly completed beverage records 
 
12.0 MATERIAL AND METHODS 
 
12.1 Human Resources for The Preparation of the Study 
- 
Three general Practitioners 
- 
One odontologist 
-     Two nurses 
-     One computer technician 
-     One social worker 
-     Four nutritionists 
 
12.2 Material Resources for the Preparation of the Study 
 
Educational program by grade level (Appendix I) 
Session 
Theme 
I. Water goes through my body 
Importance of water for health 
II. Am I drinking enough water? 
The color of urine as an indicator of the volume 
of water consumed 
III. I love water “Matarile, rile, ron” 
Ecology and water care 
IV. Together we take care of our health 
Commitment to water consumption 
 
Educational material (Appendix I) 
- Teacher by grade level 
• 
Hand puppet 
• 
Handbook for each grade level 
 
- Students by grade level 
CD 
• 
Corresponding audio-story 
• 
Exhort "1, 2, 3... I prefer to drink more water " 
• 
Water Song 
• 
Cheer for healthy urine 
Poster 
• 
Individual conclusions poster 

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Pimentel-Hernández C et.al. Versión 1.0  Fecha 19 de abril del 2017 
• 
Group conclusions poster 
• 
Healthy urine poster "Watch the color and have control" 
 
Games 
• 
Group game with dice and tokens (Fountains and Waterfalls, Waterthon Water-
challenge) 
 
Others 
• 
Wristband with the slogan “I Prefer Plain Water” 
• 
Mobile app for personal, group, and family commitments  
 
- Family 
• 
Diptych 
 
Method 
12.3 Site and Participants 
A community intervention trial will be conducted within the Coyoacán Delegation located 
in southern Mexico City. The four IG schools included in the previous study will be invited 
to participate. First graders will be recruited during the 2017-2018 school year. A medical 
examination (Appendix II) will be conducted for all participants within the school facilities 
as a direct benefit to the community. Documents regarding the original medical 
examination will be provided to the parents to be turned in at the school as requested, 
and a copy of the children’s document will be obtained for parents who consent to their 
participation in the study. All healthy children whose parents sign a privacy notice 
(Appendix IV) and complete the 3-day baseline consumption of beverages questionnaire 
will be included (Appendix V) after reading an information letter (Appendix III), being given 
the opportunity to ask questions, clarify doubts, and agree to participate in the study. The 
parents will express their acceptance via verbal informed consent. The verbal consent 
process will be documented in the file of each participant. 
 
12.4 Intervention 
At all participating schools, the principal investigator will conduct an approximately 1-hour 
briefing for parents to 1) explain the study's operational generalities and answer all 
questions and 2) provide instructions for completing the beverage consumption survey. 
Subsequently, the 3-day baseline record of beverage consumption will be collected. 

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At the beginning of the school year, first grade teachers will be trained by a nutritionist 
(one per school) to dispense the educational sessions (Appendix VI, VII, VIII), and the 
manual and materials for both teachers and students will be delivered. 
The students will receive four educational sessions of approximately 1 hour. These 
sessions will be given every 2 weeks, and some will be supervised by a nutritionist. 
The four schools will be assigned to one of the following three groups based on school 
enrollment and the interest of the teachers in participating: 
Students in Group I will receive the education strategy only during the first grade; students 
in Group II will receive the educational strategy during first and second grades; and 
students in Group III will receive the educational strategy during first, second, and third 
grades. 
 
 
1st grade 
2nd grade 
3rd grade 
Group I 
X 
 
 
Group II 
X 
X 
 
Group III 
X 
X 
X 
 
With the delivery of the first educational session, free access to water will be initiated 
through Welltek water dispensers, model WT-POU-300 A (approved and certified by 
Cofepris and the National Institute of Physical Educational Infrastructure; INIFED), installed 
inside the classrooms. Children will also receive a reusable 600-mL bottle (twice) so that 
they may consume water throughout the day. The availability of water will be guaranteed 
during four school cycles. 
 
12.5 Evaluation Process 
In September 2017, the medical examination of the students and the process of inclusion 
will be performed; instructions will be sent to parents, and teacher training will be 
conducted. During October 2017, the baseline record regarding the consumption of 
beverages will be collected (Time 1). The educational sessions will be given from 
November 2017 to January 2018. A second record (Time 2) will be obtained at the end of 
the interventions in each group (end of June), and a third record (Time 3) will be obtained 
from each group 1 year after completing the interventions (end of June). 
 
 
 

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Baseline 
End of 1st grade End of 2nd 
grade 
End of 3rd 
grade  
End of 4th 
grade  
Group 
I 
X 
X 
X 
 
 
Group 
II 
X 
X 
X 
 
Group 
III 
X 
X 
X 
 
 
 
Evaluation 1 year after completing the number of interventions associated with 
each group 
 
In addition to measurements at baseline and at each evaluation time, body weight will be 
measured, and lean mass, fat free mass, fat percentage, total body water, and BMI will be 
analyzed using a body composition analyzer via electrical bioimpedance (TANITA TBF-310 
GS). Height will be measured using a portable stadiometer (dry mark, model 213, Hambur 
Germany). Participants will be measured in light clothing (T-shirt and sport shorts) and 
without shoes. A nutritionist will be calibrated to perform the measurements. BMI will be 
classified using the WHO values standardized by age and gender. 
The following table summarizes the procedures to be performed throughout the trial. 
 
12.6 Measuring Instrument 
Beverage consumption will be recorded through a beverage journal that will be completed 
at home by the parents for 3 days (two weekdays and one weekend day). Focus groups 
will be established to modify this record (Appendix IV) and make it more understandable 
Procedure 
Sep 
2017 
Jun 
2018 
Sep 
2018 
Jun 
2019 
Sep 
2019 
Jun 
2020 
Sep 
2020 
Jun 
2021 
School medical 
examination 
X 
 
 
 
 
 
 
 
Weight, size, and body 
composition 
measurements 
X 
X 
 
X 
 
X 
 
X 
Instructions for 
completing the daily 
beverage record 
X 
X 
 
X 
 
X 
 
X 
Teacher training 
X 
 
X 
 
X 
 
 
 
Daily beverage record 
X 
X 
 
X 
 
X 
 
X 
Group I intervention 
X 
 
 
 
 
 
 
Group II Intervention 
X 
 
 
 
 
Group III Intervention 
X 
 
 

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Pimentel-Hernández C et.al. Versión 1.0  Fecha 19 de abril del 2017 
and practical for completing to improve the percentage of properly completed and 
collected journals. 
The beverage categories will be based on the 2006 National Health and Nutrition Survey, 
as follows: 
1. Water: bottled water, pitcher, mineral, or tap water; 
2. Soft drinks: cola or flavored refreshment; 
3. Sugary beverages: juices and nectars, "flavored water" (i.e., water made with powder or 
syrup), noncarbonated refreshments, and orange juice; 
4. Bottled flavored waters; 
5. Hot drinks: black coffee, tea, infusions, or cocoa; 
6. Drinkable dairy products: milk, drinkable yogurt, milkshakes, atole, whole milk, skim 
milk, fat-free milk, lactose-free milk, flavored milk, or probiotic beverages; 
7. Light drinks: light or zero-calorie soft drinks, zero-calorie flavored drinks, or zero-calorie 
teas; 
8. Bottled teas with calories; and 
9. Functional beverages: sports, energy, or isotonic beverages. 
 
 
13.0 SAMPLE SIZE 
Considering the results of the previous study where a mean difference of 80.74 mL was 
found with regard to water consumption with an SD of 399 mL as well as considering an α 
of 0.05 and a β of 0.1, we used the following formula to calculate a significant difference 
in means 
n = [ (Z1- α+ Z1- β) 2 * s2]/d2  
       [ (1.96 + 1.28)2 * 3992]/80.742 = 256.36 
N = 257 children 
The sample should include 329 first graders (allowing for a 28% loss margin) who will 
attend the 2017-2018 school year. This sample represents all of the four intervention 
schools that participated in the previous study. 
 
 
 
 
 

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2016-2017 school enrollment of the intervention schools participating in the previous 
study 
School 
Health 
Center 
First 
grade 
Total 
Second 
grade 
Total 
Third 
grade 
Total 
Total 
school 
enrollment 
Ramón 
Durand 
Ajusco 
32 
32 
64 
31 
32 
63 
26 
27 
53 
341 
Xitle 
Ajusco 
27 
29 
25 
81 
28 
27 
29 
84 
31 
30 
29 
90 
529 
Guillén de 
Lampart 
Santa 
Úrsula 
28 
26 
27 
81 
31 
32 
30 
93 
27 
27 
 
54 
475 
Tlamatini 
Santa 
Úrsula 
34 
35 
34 
103 
36 
37 
36 
101 
33 
33 
33 
99 
600 
 
329 
 
278 
 
243 
1,604 
 
 
 
 
 
Group I 
Xitle 
81 
 
 
Group II 
Guillén de Lampart 
81 
 
Group III 
Ramón Durand 
Tlamatini 
167 
       
        
Based on the school enrollment of the current school year (2016-2017), schools with the 
same number of first graders will be assigned to Groups I and II. For Group III, the schools 
with the highest and lowest enrollments will be added. 
 
 
 
 
 

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14.0 STUDY VARIABLES 
Variable 
Operational definition 
Variable type 
Unit of 
measurement 
Outcome variables 
Percentage of 
water consumed 
Average consumption of 
water/average 
consumption of total 
liquids 
Numeric/continuous 
% 
Total liquid 
Consumption 
Average amount of total 
liquids consumed per child 
over a 3-day period 
Numeric/continuous 
mL 
Water 
consumption 
Average amount of water 
consumed per child over a 
3-day period 
Numeric/continuous 
mL 
Effectiveness of 
educational 
strategy 
Increase in the percentage 
of water consumed, 1 year 
after completing the 
interventions within each 
group relative to baseline 
Qualitative/dichotomous 
 1: yes 
2: no 
Secondary variables 
Age 
Years old at the beginning 
of the school year 
Numeric/continuous 
Years 
Gender 
The sex indicated on each 
child's birth certificate 
Qualitative/dichotomous 
1: male 
   2: female 
BMI 
Indicator of the 
relationship between 
weight and height 
Numeric/continuous 
kg/m2 
Health condition 
Health condition that (in 
the opinion of the 
investigator) enables the 
participant to have free 
consumption of water 
Qualitative/dichotomous 
1: healthy 
    2: sick 
Water 
consumption per 
school 
Quantity of water 
consumed in 1 month per 
participating school 
Numeric/continuous 
L 
 
 

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Operational Definitions 
Educative intervention: Number of times that a student will receive the educational 
strategy for each elementary school year that they attend 
Educational strategy: Set of activities aimed at teaching the importance of hydrating with 
water and promoting its consumption to maintain one’s health (Appendix I) 
 
15.0 STATISTICAL ANALYSIS 
The analysis will be performed using the IBM SPSS version 22.0, and non-parametric 
statistics will be used. 
Baseline measurement of beverage consumption (Time 1). The basal consumption of the 
different beverage categories will be summarized using medians, minimums, and 
maximums. We will apply the Kruskal-Wallis test (K of independent samples) to compare 
the differences in baseline beverage consumption among the three groups. 
Baseline measurement and at the end of the interventions (Times 1 and 3). The percentage 
of water consumed at baseline will be compared with that 1 year after finishing the 
intervention for each group using the Wilcoxon test. 
Comparison among the three groups. The percentage of water consumed will be 
compared among the three groups 1 year after the intervention is completed using 
Friedman’s test of related samples. 
 
16.0 ETHICAL CONSIDERATIONS 
According to the Regulations of the General Law on Health in the Field of Health Research 
and the provisions of Article 17, this project is considered a study with minimal risk. 
As a minimum risk investigation and in accordance with NOM-012-SSA3-2012 (item 11.3, 
paragraph 2), the Research Ethics Committee will be requested to approve the proposal 
that the associated researchers be allowed to request informed consent verbally. To 
guarantee the confidentiality of personal data, a privacy notice will be signed. 
The dignity of the participants will be respected, their rights and well-being will be 
protected, and ethical clinical practices will be followed. 
The team of researchers associated with this study has no conflicts of interest to declare. 
The research protocol will be submitted for approval to the Research Committee and 
Research Ethics Committee of the National Institute of Pediatrics. 
 

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17.0 BIBLIOGRAFÍA 
 
1. Dieta, nutrición y prevención de enfermedades crónicas. Informe de un grupo de 
estudio de la OMS. Ginebra, Organización Mundial de la Salud, 1990 (OMS, Serie de 
Informes Técnicos, Nº 797). 
2. Rolls BJ. Fat and sugar substitutes and the control of food intake. Annals of the New 
York Academy of Sciences. 1997; 819:180-193.  
3. Ludwig DS. The glycemic index: physiological mechanisms relating to obesity, diabetes, 
and cardiovascular disease. Journal of American Medical Association. 2002;287:2414-
2423.  
4. Ebbeling CB, Ludwig DS. Treating obesity in youth: should dietary glycemic load be a 
consideration? Advances in Pediatrics. 2001; 48:179-212.  
5. Ludwig DS, Peterson KE, Gormakaer SL. Relation between consumption of 
sugarsweetened drinks and childhood obesity: a prospective, observational analysis. 
Lancet. 2001; 357:505-508. 
6. Raben A et al. Sucrose compared with artificial sweeteners: different effects on ad 
libitum food intake and body weight after 10 week of supplementation in overweight 
subjects. American Journal of Clinical Nutrition, 2002, 76:721-729.  
7. Mann JI et al. Effects on serum-lipids in normal men of reducing dietary sucrose or 
starch for five months. Lancet. 1970; 1:870--872.  
8. Mattes RD. Dietary compensation by humans for supplemental energy provided as 
ethanol or carbohydrate in fluids. Physiology and Behaviour. 1996; 59:179-187.  
9. Tordoff MG, Alleva AM. Effect of drinking soda sweetened with aspartame or high-
fructose corn syrup on food intake and body weight. American Journal of Clinical 
Nutrition. 1990; 51:963-969. 
10. Harnack L, Stang J, Story M. Soft drink consumption among US children and 
adolescents: nutritional consequences. Journal of the American Dietetic Association. 1999; 
99:436-441.  
11. Ludwig DS, Peterson KE, Gortmaker SL. Relation between consumption of sugar-
sweetened drinks and childhood obesity: a prospective, observational analysis. Lancet. 
2001; 357:505-508.  
12. Théodore F, Bonvecchio A, Blanco I, Irizarry L, Nava A, Carriedo A. Significados 
culturalmente construidos para el consumo de bebidas azucaradas entre escolares de la 
Ciudad de México. Rev Panam Salud Publica. 2011;30(4):327– 34. 

24 
Pimentel-Hernández C et.al. Versión 1.0  Fecha 19 de abril del 2017 
13. Discurso del Presidente de la República en el marco del Día mundial de la salud, 
celebrado el día 2 de abril de 2013. http://www.presidencia.gob.mx/articulos-prensa/dia-
mundial-de-la-salud-2013-la-hipertension/ 
14. Plan Nacional de Desarrollo 2013-2018-DOF_ Diario Oficial de la Federación. 
http://www.dof.gob.mx 
15. Diario Oficial de la Federación. Lineamientos generales para expendio y distribución de 
alimentos y bebidas en las escuelas. 23  agosto 2010. 
16. Wang D, Stewart D. The implementation and effectiveness of school-based nutrition 
promotion programmes using a health-promoting schools approach: a systematic review. 
Public Health Nutr. 2012; 16:1082-1100. 
17. James O. Prochaska, Collen A. Redding, Kerry E. Evers. The transtheorical model and 
stages of change in HEALTH BEHAVIOR AND HEALTH EDUCATION Theory, Research, and 
Practice; 4th edition, Jossey-Bass editors, pp 97-101.