Claudia Willis (ccw885)NTR338WFinal Draft

EFFECTIVENESS OF PREVENTION PROGRAMS ON CHILD OBESITY

Abstract

The increase in childhood obesity has become an international issue.

Obesity is a leading factor in many deadly diseases. In recent years studies have

been conducted to try to find the best method of lowering obesity rates. The

evaluation of prevention programs during and after school has shown some

positive influence in solving this epidemic. Studies have been separated by focus

either in nutrition education, physical activity, or both. In this review, a variety of

outcome measures including anthropometrics, questionnaires, behavioral

analysis, and diet were compared to evaluate what methods result in the highest

amount of positive change in health. Some differences were found in BMI and

healthy food intake but overall there is still a large need for longer-lasting

changes to be implemented to prevent obesity.

Introduction

Child obesity rates have been increasing for several decades, and has

now become an international epidemic [8]. This is largely due to a shift in lifestyle

habits such as unhealthy eating and inadequate physical activity. It is estimated

that over one-third of children in our nation fall under the category of overweight

or obese [5]. Child obesity is a large link in a chain leading to long-term adult

health risks, like cardiovascular disease and diabetes. The consensus of

literature on the matter agrees that the most effective way to address the

problem of child obesity and the associated life threatening diseases leading into

adult obesity is through prevention interventions. The focus of this research is to

evaluate the effectiveness of afterschool programs in correcting and preventing

childhood obesity.

It is important to outline three main factors that influence the prevalence of

child obesity; behavior, environment, and family [10]. A child’s behavior and

attitude towards a healthy lifestyle for example depression, low self-esteem, or

social anxiety can cause over-eating especially in the post adolescent

demographic. Additionally, sedentary behavior is probably the biggest contributor

to a lack of adequate physical exercise. Children are now more involved in

watching television or using electronics; therefore, they are not burning as much

energy as they would if they were taking part in physical activities. This leads to

the environmental factors that increase the likelihood of child obesity. The media

plays a role in constantly exposing youth to advertisements of unhealthy food

items and sedentary influencers that are targeted specifically to children. School-

based policy is a direct environmental influence on the amount of physical activity

and nutrient-rich foods available to children. Nationwide, only 4.2% of elementary

schools require daily physical education for all students [3], while it is

recommended that children get at least 60 minutes of moderate to rigorous

exercise a day [10]. Another example is community influence; low-income areas

are less likely to provide healthy food choices, grocery stores, community

gardens, or neighborhood health initiatives. Lastly, family influences like

socioeconomic status affects a child’s health outcome. For example, some

families cannot afford expenses such as sport equipment to join a team. Also

cultural background affects the types of foods eaten, along with ideals on home

cooking versus eating out. Family influences include a genetic predisposition to

obesity and certain ethnicities that are more genetically inclined towards obesity

[10]. African-American and Latin-American populations are the most at risk for

child and adult obesity [5].

There are a variety of factors to evaluate when determining the efficacy of

afterschool programs in preventing child obesity; there are major differences in

the successes and failures of the many programs implemented and evaluated.

Greater positive results are outlined by specific factors. One factor was the

experience of leaders implementing the program and the outside support they

received. The most effective physical intervention program, led by trained study

personnel with exercise-related education had the most significant results in

lowering BMI (body mass index)[5]. Another study suggested nurses and staff

training would have greatly influenced the success of the program, because

parent involvement would have aided the children in sustaining the practices they

learned and continued exposure to the habits [14]. Attendance was an area

where many programs struggled; success rates were much higher in programs

with greater attendance [3]. The focus of many programs split between nutritional

and physical activities. For example, some programs implemented exercise and

eating habit lessons while others focused specifically on either physical

improvement or providing information on healthy eating habits. The method of

exercise influences results, for example, the intense forms of aerobic activity

provided significant outcomes in reducing BMI and other biological determinants,

rather than providing a less intense form of exercise like play time [5]. Longevity

of the program was a varying factor in many of the programs, some as short as

eight weeks and the longest being almost four years [3]. One three-year HOP’N

(Healthy Opportunities for Physical Activity and Nutrition) program had a positive

influence on increasing children’s physical activity but provided no impact

changes on BMI [7]. An additional problem many of the programs faced was

seasonal changes; consistency was lost over the summers when the program

could not run, and this negatively affected some results [2]. Another negative

feature of some studies is a lack of follow up evaluations. This is key in keeping

sustainability of the program after the fact and evaluating how much influence a

program made following into adulthood. There is no overwhelming evidence in

support or against the idea that afterschool programs are definitive in preventing

child obesity, but there are positive results to examine. The purpose of these

studies is to introduce lifestyle changes, such as eating healthier and doing more

physical exercise starting at a young age with the hope that these practices are

continued into adulthood. The objective of this review is to evaluate what

methods of intervention in afterschool programs provide the best results for

preventing obesity.

Methods

A literature search was done in order to collect studies for this review. The

first search was conducted using the University of Texas at Austin library

“ScoUT” database. This search engine looks through all available educational

based literature from a variety of subject specific resources like Wiley Online

Library, PubMed, Web of Science, and a number of Journals pertaining to

nutritional studies. The necessary inclusion criteria included: (1) must be

published in English; (2) must be available online; (3) limit to articles from peer-

reviewed publications; (4) must be published between 2010-2015. This narrowed

the related articles. Some keywords and sentences used were “child obesity and

physical activity” or “child obesity prevention AND intervention”. My second

search was done using the Endnote search engine exclusively linked to the

PubMed database, after typing in the keywords “Child Obesity prevention

programs AND after school AND school based” it resulted in a number of

additional case studies to review on.

Six main articles were chosen that provided a variety of subject

characteristics to compare but all still following a similar design for intervention.

A study conducted by C. Howe et al. pertained strictly to young overweight male

black boys and the physical results from intense physical activity intervention.

This study is unique in that it includes only one demographic with a specific

program focus on physical activity, but designed to have a short duration of only

ten months. The outcome measures of this small sample of 106 participants

cluster-randomized trial were body composition, cardiovascular fitness, and

physical activity assessments [5]. A study lead by Z. Yin et al. much like the

previous study also focused strictly on physical activity intervention with similar

intensity but for a greater period of time of three years versus ten months. This

cluster-randomized trial had a medium sample of 572 participants. Researchers

focused on finding differences in percent body fat and cardiorespiratory fitness

levels [22]. This next study by author U. Meyer et al. was a cluster-randomized

trial with a medium sample size of 502 subjects conducted in Switzerland. This

study also focused on a strictly physical activity intervention much like the ones

previously mentioned. The duration of this study was one of the longest because

although the intervention was only 9 months, follow ups were conducted three

years later, making it almost four years in length from start to finish. Some

outcome measures such as percent body fat, aerobic fitness levels, and physical

activity levels were considered and analyzed in this time. One unique outcome

measure in this study was a questionnaire on quality of life conducted before and

after the intervention [13]. The HOP’N program study by D. Dzewaltowski et al.

provided the largest sample of 961 participants. This study design was much

heavier on follow up and consistency of habits throughout the three-year

duration, rather than immediate results. This randomized control trial focused on

both physical activity and nutrition education. The outcomes measured in HOP’N

were BMI, physical activity levels, and pre/post tests [7]. Another study

conducted by L. Nabors et al. is similar to the HOP’N study in that it has a split

focus on nutritional education and physical activity, but unlike the other studies it

used a sample of only 54 participants for this pilot study. The outcome measures

include parent and child satisfaction ratings, pre/post surveys, and coaching

interviews [14]. This last study by C. Herscovivi et al. was a randomized trial with

a medium sample size of 369 subjects. This was the only study with the sole

focus of the intervention program be nutritional education based. This study took

place in a low-income area of Argentina. Outcomes were compared by gender

and evaluated by BMI and intake questionnaires [16].

Results

A total of 22 articles were chosen to evaluate for this review, with a main

focus on six particular intervention studies. Five of which were randomized

control trials, and one pilot study. The number of participants in each study

ranged from 54 to 961, and ages varied from 1st to 5th grade. Two of the studies

were conducted abroad in Switzerland and Argentina, while the other four were

conducted all across the United States. Across the six main studies there were a

variety of demographics included. African-American, Latin-American, and

Caucasian ethnicities were the most prevalent and accounted for. Most studies

also documented gender percentages and socio-economic status by income

area or qualification for free/reduced lunch. The results of this research will be

compared by outcome measures, and additionally evaluated by program focus;

(1) physical activity (PA), (2) nutrition and health education (NTR), and (3) both

nutrition education and physical activity (PA+NTR).

The first study evaluated is the most intense PA program on the spectrum

for physical activity interventions. This study by C. Howe et al. has the most

significant changes in outcome measures from baseline to follow up. The study

design for this program had a vigorous schedule of 80 min of MVPA (moderate to

vigorous physical activity) lead by a trained personnel staff five days out of the

week. When looking at the results of these African-American male participants,

the intervention group had a significant lower body fat percentage of -2.25 versus

the control group, which only lowered -0.63 (figure 1). The intervention group with

higher attendance was also successful in lowering BMI by -0.2 while all other

groups BMI actually increased (figure 2). The intervention group with the greater

attendance was able to improve their Vmax oxygen levels, which was a unique

outcome measure for this study. The largest change by far was the amount of

MVPA (figure 3). From baseline to follow up it increased 34.8 minutes a day [5].

The following strictly PA intervention study conducted by Z. Yin et al. was

similar in that it that it included 80 min of PA, but was lead by a less qualified

staff. The study stated that there were no significant differences in any of the

outcome measures from baseline to follow up. Although the control group did

improve in some of the outcome measures many of the results fluctuated due to

some faults in the study design. For example WC (waist circumference) improved

in the intervention groups after a one-year follow up, but by the three-year follow

up WC lowered to a similar value of that at baseline. Similar trends in the other

outcome measure values like %BF (percent body fat) were present [22].

This next PA focused study conducted by U. Meyer et al., provided no

significant results in primary outcomes from pre-to-post intervention. Only one of

the secondary outcomes improved despite no significant changes in body

composition from the skin fold tests, there were increases in the shuttle run test

for the intervention group versus the control group at the three year follow up

after the nine month intervention (figure 4). A problem in the reliability of these

results is due to a 58% drop out rate by the end of the last follow up [13].

The HOP’N study conducted by D. Dzewaltowski et al. is one example of

a study that tried to incorporate both physical activity and nutritional health into

the design (PA+NTR). Although this PA+NTR focused study resulted in no

anthropometric changes in BMI between intervention and control groups there

was a significant change in MVPA in the overweight intervention group. From

baseline to one-year follow up MVPA went from less than 12 minutes to about

15, then from one-year to two-year follow up it increased to about 18 minutes of

MVPA (figure 5). The PA of this study was less vigorous than in other PA

interventions because it used “sports engagement” as the form of PA instead of a

stricter measurement of MVPA by heart rate or Vmax oxygen levels. The study

incorporated some nutritional education by presenting some information on

important health practices before each PA lesson, researchers also recorded F/V

(fruit and vegetable) intake by counting the choice in snack that participants

chose each day [7].

In this next PA+NTR focused study by L. Nabors et al., incorporated a

design that allowed for playtime, which included some physical activity, but there

were no outcomes based on any anthropometric or clinical measures. The

results of this study showed that children in the intervention groups had a decline

in the number of unhealthy sweet food items, and increase in fruit intake. This

was measured using pre/post testing and recall of meals. Also 71.4% of the

intervention participants correctly identified non-healthy foods and 91% were able

to identify healthy food items based off the “Traffic Light Diet” nutrition education

lessons [14]. Both PA+NTR focused studied used untrained personnel when

leading these programs.

This last NTR only focus study conducted by C. Herscovici et al. placed an

emphasis on gender differences in low-income areas in Argentina. These results

were heavily outlined by nutrient education outcomes versus physical activity

outcomes. Although there was no significant change in BMI the nutrition and

health programs helped provide significant positive results in the female

demographic. The girls in the intervention groups made more choices in

consumption of healthy food items versus the boy intervention groups. Overall

the program positively influenced the intake of healthy food items, but was

unable to significantly change the intake of unhealthy food items (figure 6). This

intervention was unique in that it was able to modify the cafeteria food being

offered at the intervention schools, and supplemented meals with healthier food

items to choose from [16].

Discussion and Conclusion

When analyzing an accumulation of data from a variety of outcome

measures, trends begin to arise between certain study designs and positive

results. For example BMI changes were evident when PA program intervention

was vigorous. Also researchers were much more likely to increase F/V healthy

food intake than to decrease unhealthy food intake in intervention participants.

These trends help outline the attributes that when incorporated into a study’s

design provide better outcomes in results. Incorporating a strict program focus is

more likely to result in more positive data than split focus. For example if

nutritional education is the main focus, researchers should stick to making

differences in knowledge outcomes and not expect drastic BMI changes from

lessons on healthy food items. A more intense PA guided exercise routine that

incorporates MVPA not just “playtime” exercise. Also restricting the program

duration to one or two years in length. Too long of a program looses participants’

interest, but one year is enough to make anthropometric changes that

participants will want to continue improving upon. Lastly outside program

involvement pertaining to using trained personnel, experienced coaches, and

incorporating a high amount of parent involvement.

When looking at the results from the PA interventions you can tell how one

result in particular indicated the importance of consistency. In the study

conducted by C. Howe et al., the changes in MVPA from base line to follow up

ten months later show a consistent increase of not only duration of exercise but

also vigor [5]. It would be beneficial for the study to follow up again multiple years

later to see if that consistency and increase of MVPA remained. This point of

consistency is important to evaluate because continuing these healthy exercise

habits is the only way to ensure prevention of obesity in later years. We cannot

truly evaluate the success of an obesity prevention program imposed on children

unless we can also determine the outcome of their health as an adult. The

following PA study by U. Meyer et al., which resulted in no significant differences

in any outcomes from the beginning of the study to the end of it, were due to

many holes in its design. The study had a skew in results due to gaps in the

program duration. Duration of the program was a huge problem. There were

three studies that lasted up to three years or more from baseline to follow up, and

all of those studies had a lower number of positive results on outcome measures

than any of the other programs that were shorter in length [7,13,22]. Logically,

one would think with a longer program it would allow for more repetition and

therefore a more consistent change in habits. In these studies that wasn’t the

case at all. The problem most likely lies in that the programs are school-based,

and during the summers no school takes place so there is a lot of time and data

that is lost.

The two PA+NTR studies had some interesting trends in common.

Although these programs focused on physical activity and nutritional education,

the outcome measures for nutrition education were more positive than for those

of physical education. In both studies there was no change in BMI for intervention

groups, but there were positive changes in eating habits and improvements in

intake of healthier food items [7,14].

The one NTR study was completely dependent on behavioral changes

and changes in knowledge about nutritional food items. Many of the differences

in base line to follow up were determined by diet recall of participants. For

example, the children would interview and fill out questionnaires that asked them

what they ate the day before. When dealing with participants that young of age

their memory isn’t always reliable and this leaves room for many errors in

accurately documenting data [16].

Some of the strengths in these studies were the use of large sample sizes,

providing multiple follow-ups to track progress, using trained personnel, and

having a varying amount of intervention program. This variety ranged from

programs that provided four workshops over a six month period to a daily boot

camp type work out five days a week over a ten month period. Many of the

studies conducted built off of one another to improve upon the mistakes made in

other studies. For example, in the gender comparison study they provided

healthy snacks and were able to modify the cafeteria menu items [16]. Another

gender specific study using an all female group called the “LA Sprouts” did

something similar in emphasizing an even greater focus on providing and

growing healthy food items, to have these nutritionally superior food items as

immediate choices [9]. This influences what the participants consume, and with

exposure to healthier food items you are more likely to eat them rather than just

learning about healthy food items but never actually seeking them out to eat. This

was just one example of how these studies are continuously improving upon one

another to be more effective.

Some limitations of these studies included, low parental involvement, high

drop out rates, gaps in program duration, consideration of sexual maturation, and

reliability of diet recalls in children. Participation was a huge challenge for many

studies. It is normal to lose participants over time in a study, but many long-term

studies had to suffer loosing large portions of their participants. This lead to an

increase of sample sizes and monetary compensation for continued involvement.

This problem is still ongoing, and keeping participants involved in a study is

difficult but many research teams are developing ways to improve upon this

problem.

From an initial perspective to now, I thought that research on the topic of

child obesity would result in more positive findings. Although some difference has

been made, an issue of this spectrum and morbidity should have a greater

amount of significant changes. A problem of this magnitude needs a solution,

and the steps being taken are still minimal compared to the drastic changes

necessary. Ideas for future research are coming about to generate these

changes like using celebrity lead programs to motivate children to participate in

more exercise activities and lower drop out rates. Also gearing research to

propose policy changes like increasing budgets for school lunch programs to be

able to afford healthy options. Ultimately, a lifestyle change needs to be made

starting from the beginning of schooling. Greater education on nutrition and what

healthy foods are, along with intensely guided physical activity, are what will

make the greatest influence starting from a young age.

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Appendix

Figure 1: C. Howe et al.

Figure 2: C. Howe et al.

Figure 3: C. Howe et al.

Figure 4: U. Meyer et al.

Figure 5: D. Dzewaltowski et al.

Figure 6: C. Herscovici et al.

CHARTS:

ARTICLE

TYPE OF STUDY

DESIGN # OF SUBJECTS

OUTCOMES

MEASURES

RESULTS DISCUSSION POINTS

Lngterm effcts of a KISS fitness & adiposity

Intervention-PA

Cluster-randomized control trial

50228 classes15 schols(289 followup)

BFAerobic fitnisPAQualofLIfe

SkinfoldShuttle runAccelomtrquestionare

I>C group in AFEffects not maintained

9 monthsfollow up-3yrsnot already fat kidsin switzerland

Gender diff and obese prevention in ARG

Intervention-NTR ed

Randomized trial

369 cldrn9-11 yrolds6 schls

Intake of healthy v unh Questionares

BMI

Girls had better results

6monthsbetter at promoting healthy foods than cutting back unhelth foods-boys v girls-poor ppl

HOP’N Intervention-PA-NTR ed

RCT 9613-4 grade8 schools

Chng in ageGndr BMI z-scPA -accelomtr

BMIsPA v sedPre/post tests

PA vs sed was positive BMI – no sig changePre/post =+R

Time= 3yrsSplit focusG+BF/V eval

10-month PA in Black boys

Intervention-PA

RCT 1068-12 yrsonly black boys

ATT- <60%NATT->60%CNTRL

CVBody compPA

ATT dcrs in %BFCV- similar -CNTLbest

Time= 10 mnth

Impact of 3 yr ASOPP in elem schl

Intervention-PA

Cluster random

5723rd grd18 schools

Only for 60% atten

%BFCRFCMM

%BF & CRF positive for intervention- no diff in cholesterol or BP b/t cntl and interv grps

80 min wkoutTime = 3 yrLost over summers

Impl of ASOPP; help young chld towrd improved hlth

Intervention-NTR ed- play time

pilot 54 chld2 schools

Traffic light diet- eating habitsCHEE/CATCH- Activity levels (AL)

Prnt/chld satisfactionPre/post surveyCoaching – MI interviewing

Incrs in ALRest of data insig

Nurses and training improving resultsGreen v redComm problemScl1 – blk/classschl2- wht/gym

Study Type n Age Duration Location Intervention

C. Howe et al.

Randomized Control

I=62C=44106

8-12 10 months USA PA (physical activity)AS (after school)

Z. Yin et al.

Cluster Randomized

574 7-9 2 yrs and 9 months

USA PAAS(FitKid Program)

U. Meyer et al

Cluster Randomized Control

I=297C=205502

6-13 9 months (then followup 3 yrs later)

Switzerland PAAS(KISS program)

D. Dzewaltowski et al.

Cross-sectional Randomized Control Trial

961 9-11 3 yrs USA PA+NTRAS(CATCH and HOP’N programs)

L. Nabors et al.

Pilot 54 4-9 2 yrs (summers only)

USA PA+NTRAS(CATCH and Traffic Light Diet programs)

C. Herscovici et al.

ProspectiveRandomized Control Trial

I=205C=164369

9-11 6 months Argentina NTRDS (during school)