Childhood obesity - research
University Ss. Cyril and Methodius – Skopje
Medical Faculty
CHILDHOOD OBESITY
Student:
Mentor:
Rodna Guguljanova
Prof. Mome Spasovski MD, PhD
Skopje, June 2015
CONTENT:
1. Abstract ……………………………………………………………………………………………….2
2. Introduction ………………………………………………………………………………………...3
3. Definition of child overweight and obesity ………………………………………….4
3.1. Social-economic factors ……………………………………………………………..5
4. Risk factors of childhood obesity …………………………………………………………6
4.1. Main results related to key messages …………………………………….….7
4.2. Conclusion and future perspectives …………………………………………...9
5. Prevention ……………………………………………………………………………………………10
5.1. Local governments’ role in reversing the obesity epidemic ……….10
6. Community should do ………………………………………………………………………….11
7. Conclusion ………………………………………………………………………………………….…17
8. References ……………………………………………………………………………………….…..18
1
1. Abstract
Childhood overweight and obesity are major public health problems worldwide. Traditionally,
a heavy child meant a healthy child, and the concept “bigger is better” was widely accepted.
Today, this perception has drastically changed based on evidence that overweight and obesity in
childhood are associated with a wide range of serious health complications and increased risk of
premature illness and death later in life.
The purpose of my seminar paper is to write and make aware of this problem. Childhood
obesity (target group: 2 years-18 years old) continues to be a major challenge for almost all
countries in the European Region. The statistics are disturbing, with rising rates of overweight
and obesity reported in many countries of the region during the past few decades.
Programs now clearly demonstrate that childhood obesity can be prevented. Cardiovascular
fitness, physical function and quality of life can also be markedly improved. There are several
ways to reach these goals. It is high time to stop multiplying basic experimental programs,
except for original unexplored aspects, and act at the highest possible level. Funding should be
invested in implementing widespread prevention and treatment strategies..
Some of the strategies and methods used to decrease the number of overweighed children have
showed success. Health organizations and institutions all over the world are trying hard to help
with this problem.
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2. Introduction
Obesity has always existed, although it used to be very rare in children. Trouble arose when its
prevalence started rising dramatically first in wealthier countries then all around the world. This
led to the understanding that obesity reflects a loss of adaptation of individuals to their
environment. This came as a surprise because of the belief that the environment was supposed to
have reached a peak in its quality since humankind has been acting on it.
A few years were sufficient to observe that 80% of obese children around 10 years old would
likely become obese adults. Despite such an alarming situation, great confusion about the way to
tackle obesity still persists for two main reasons: this condition is much more complex than we
had initially thought, and our understanding of it is still limited. Complexity applies to the
underlying pathways, which, like in cancers, vary among individuals, although the general
mechanism is always that energy intake exceeding energy expenditure leads to its storage in the
form of fat tissue. Obesity-related science permitted a number of fascinating discoveries, not
least that adipose tissue is an endocrine organ, that the gut flora is also an organ, and that both of
these interact continuously with the brain. Gene expression is modified from conception onward
via epigenetic mechanisms, i.e. through, for instance, the nutritional environment, pollutants and
microbiota. This process starts in utero, indicating that good health is also dependent on the
mother’s lifestyle before birth. Complexity also applies in the clinical diagnosis, management
and prevention of obesity.
The prevalence of obesity in children is increasing in most regions of the world. Recent data
indicate that this trend has leveled off in some developed countries like the US, Australia, and
some European countries, but the level is still too high. As the causal pathway leading to obesity
already starts early in life it is important to understand the causes and mechanisms leading to this
disorder and to find a way for effective primary prevention interventions in young children.
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3. Definition of child overweight and obesity
In recent years, BMI has been used as a valid, if indirect, measure of adiposity in adults, and
increasingly accepted as measure of adiposity in older children and adolescents for survey
purposes and this has led to various approaches to selecting appropriate BMI cut-off values to
take account of the fluctuations in BMI during normal growth.
Difficulties in making comparisons between surveys that used different national reference
curves led to the establishment of an expert panel, convened by the International Obesity Task
Force (IOTF), which proposed a set of BMI cut-offs based on pooled data collected from Brazil,
Britain, Hong Kong, Singapore, the Netherlands, and the USA. The panel agreed that overweight
and obesity would be defined in children according to the BMI centile curves that passed through
the cut-off points of BMI 25 and 30 at age 18. The resulting set of age- and gender-specific BMI
cut-off points for children was published in 2000. A more detailed version of this approach,
extending the cut-offs to include BMI 35 and 40 at age 18, at monthly intervals from age 2 to 18
years was published in 2012.
Fig 1: Comparisons of measured and selfreported estimates of overweight and obesity in
selected countries
Overweight defined by IOTF criteria (includes
obese).
Source: OECD 2013
4
The highest child obesity prevalence levels in this region are found in several southern European
countries. The Child Obesity Surveillance Initiative which has introduced a uniform surveillance
methodology in several European countries, shows overweight prevalence (including obesity)
among children aged 7-8y to range from 15% in Norway to 36% in Italy.
Table 1: Child obesity in selected European countries
3.1.
Socio-economic factors
Examination of differences in the distribution of overweight and obesity among children coming
from different social classes (defined by family income levels or educational levels of the main
income earner, or local indices of deprivation) shows a complex pattern.
In countries which are not economically developed, or are undergoing economic development,
overweight and obesity levels tend to be higher among families with larger incomes or higher
educational attainment. In Brazil, in 2005, 38% of 11-year-old children in higher-income families
were overweight or obese (WHO definition), compared with 26% of children in middle-income
families and 20% of children in lower income families. In China there is a similar association
between child overweight and family income level and educational level. In a review across many
developing countries, the determinants of risk of obesity were found to be: “high socioeconomic
status, residence in metropolitan cities, female gender, unawareness and false beliefs about
nutrition, marketing by transnational food companies, increasing academic stress, and poor facilities
for physical activity”.
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4. Risk Factors of Childhood Obesity
The IDEFICS study (Identification and prevention of dietary- and lifestyle-induced health effects
in children and infants) investigated the etiology of diet- and lifestyle-related diseases and disorders
with a strong focus on overweight and obesity in a large population-based cohort of 16,228
European children aged 2 to 9 years who were recruited from eight European countries. According
to a standardized protocol, weight status and related health outcomes such as blood pressure and
insulin resistance, direct behavioral determinants such as physical activity and diet and indirect
determinants such as social/ psychological factors and consumer behavior were measured. In this
way, the study tried to disentangle the causal pathways leading to obesity and other health
outcomes by analyzing the complex interplay of potential risk factors. Details of the objectives,
original study design, the proposed measurements and a description of the study sample have been
published previously. Furthermore, the IDEFICS study developed, implemented and evaluated a
setting-based community-oriented intervention programme for primary prevention of obesity in a
controlled study design. For this purpose, in each country intervention and control regions were
selected with a comparable socio-demographic profile. In the intervention regions, a coherent set of
intervention modules were implemented, focusing on diet, physical activity and stress-coping
capacity captured in six key messages.
Based on the major suspected risk factors for the development of obesity, i.e. physical activity,
dietary and stress-related behaviors, the IDEFICS intervention focused on three main intervention
areas formulated as six key messages:
(1) increase daily physical activity levels,
(2) decrease daily television (TV) viewing time,
(3) increase the consumption of fruit and vegetables,
(4) increase the consumption of water,
(5) strengthen parent-child relationships and
(6) establish adequate sleep duration patterns (see Figure 2).
Figure 2:
6
Figure3: Percentage
of
children
adhering
recommendations based on the six key messages
to
4.1.
Main results related to key messages
Diet: There are identified four major dietary patterns: snacking, sweet/fat,
vegetables/wholemeal, and protein/water in children´s dietary behaviour assessed by food frequency
questionnaires.
Further effects of dietary behavior can be observed taking TV viewing additionally into account as
potential risk factor.
TV viewing: Some organizations have investigated the association between daily TV
time and the presence of a TV/video/DVD in the child´s bedroom and overweight /obesity by
estimating odds ratios adjusted for sex, age and parental education. Both, having a TV in the child´s
bedroom and consumption daily TV time of more than 60 minutes showed a positive association with
the weight status of children in all countries. It could also be shown that, independent of taste
preferences, children who watched more TV had a higher propensity to consume foods high in fat
and/or sugar.
Moreover, associations between screen habits and sweetened beverage consumption were
observed which could also be seen longitudinally: children who were exposed to commercial TV at
baseline (T0) had a higher risk of consuming sweetened beverages at T1. A further longitudinal
analysis revealed a substantial impact of TV viewing and other screen habits on the consumption of
sugary drinks and on increase in BMI.
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Physical activity: A ‘movability index’ was developed as a tool for urban planners to
reflect opportunities for physical activity in the urban environment of children. Based on
geographical data, the index integrated different urban measures such as the availability of
destinations, i.e. playgrounds, green spaces and sport facilities, as well as the street connectivity
considering intersections, foot paths and cycle lanes that were both assessed using a so-called
kernel density approach (Figure 4). Additionally, residential density and land use mix were included
in the index. In a pilot study that was conducted in the intervention region in Germany, it was
shown that opportunities for physical activity in the urban neighborhood of school children, i.e.
short routes and particularly the availability of destinations were positively associated with physical
activity levels.
Figure 4: Availability of playgrounds within the
German intervention community, Delmenhorst,
estimated via kernel density
The analysis of physical activity concentrated on its effect on bone stiffness and weight status.
The duration of moderate-to-vigorous physical activity (MVPA) is showing huge variations
across Europe and had a protective effect against overweight/obesity, in particular in school-age
children. The prevalence of obesity was elevated in children exercising less than the
recommended 60 minutes moderate-to-vigorous physical activity per day (Figure 5).
Figure 5: Duration of MVPA (60
sec. interval) by age and weight
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Family life: Is is observed a clear gradient of an increasing prevalence of
overweight/obese children ranging from a prevalence of 17.1% among those sitting always
together to a prevalence of 36.2% among those who reported to never/rarely sit together during
meals.
Sleep: Sleep duration is showing marked variation across Europe, but exhibited
an ecological correlation with the prevalence of overweight/obesity. This correlation was
confirmed by individual level analysis as sleep duration was negatively associated with weight
status, particularly in school-age children (see Table 2).
Table 2: Odds ratios (OR) and 95% confidence intervals (CI) for the association between sleep
duration and overweight/obesity (reference > 11 hours)
Multivariate linear regression and quantile regression models confirmed an inverse relationship
between sleep duration and measures of overweight/obesity. The estimate for the association of
sleep duration and body mass index (BMI) was approximately halved after adjustment for fat
mass (FM), but remained statistically significant. The strength of this association was also
markedly attenuated when adjusting for insulin mainly for the upper BMI quantiles. This means
that the inverse relationship between sleep duration and BMI is mainly explained by the
association between sleep duration and FM.
4.2.
Conclusion and future perspectives
The above summary of some of the results obtained from the IDEFICS cohort confirms that
childhood obesity results from a complex interplay of a variety of health-related lifestyle factors.
The living environment, social conditions, economic pressures and family lifestyles have
drastically changed over recent decades. Often both parents are working and the time spent
together with their children is limited. Self-prepared meals from local ingredients are replaced by
fast and ready-made foods. Concerns about safety on the streets, limited availability of play
spaces, exposure to TV and increased time playing computer games have pushed physical
activity out of the daily lives of young people. These changes profoundly impact children’s
health, particularly those in the most vulnerable groups.
Even if children decide to accept healthy eating and activity patterns, their lives will
change considerably as they become teenagers. Healthy routines can easily be lost and replaced
by unhealthier habits, perhaps because of the influence of marketing or peer pressure.
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5. Prevention
5.1.
Local Governments’ Role in Reversing the Obesity Epidemic
Many aspects of our physical environment that influence our health are created, managed, and
maintained by local governments. For example, local policies and incentives can affect the
presence and absence of parks, sidewalks, bike lanes, mixed-use development, healthy food
retailers, and farmers markets. Public schools—although not under the authority of local
governments—also have a vital role in ensuring that children have access to healthy food and
sufficient opportunities for physical activity during the school day.
Clearly, local governments and public school systems can make a real difference in creating
healthy food and activity environments that benefit all people living in their communities.
Aside from the health benefits, there are also economic benefits to local governments for
creating walkable, safe, and food-secure environments. For example, home values are expected
to rise faster in “smart communities” that are made pedestrian-friendly by employing mixed-use
development, sidewalks, and traffic-calming features.
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6. Communities should do
Increase availability of healthier food and beverage choices in public
service venues
Limited availability of healthier food and beverage choices (e.g., foods with low calorie, sugar, fat, and
sodium content) can be a barrier to healthy eating and drinking. Public service venues, such as schools,
child care centers, city and county buildings, prisons, and juvenile detention centers, are key venues for
increasing the availability of healthier foods. Improving the availability of healthier food and beverage
choices (e.g., fruits, vegetables, and water) may increase the consumption of healthier foods.
Improve availability of affordable healthier food and beverage choices
in public service venues
Healthier foods are generally more expensive than less healthy foods, posing an economic
barrier to healthier eating, particularly among low-income populations (Drewnowski, 2004).
Public schools and local governments can improve the affordability of healthier foods and
beverages sold in public service venues by establishing policies that lower prices of healthier
foods and beverages relative to the cost of less healthy foods sold in vending machines,
cafeterias, and concession stands in schools and local government facilities. Other strategies to
make healthy food more affordable include offering coupons or vouchers redeemable for
healthier foods and incentives or bonuses for the purchase of healthier foods.
Improve geographic availability of supermarkets in underserved areas
Supermarkets have a larger selection of healthy food at lower prices compared to smaller grocery
stores and convenience stores. However, research indicates that low-income, minority, and rural
communities have fewer supermarkets as compared to more affluent areas (Larson, Story, &
Nelson, 2008; Morland, Wing, Diez Roux, & Poole, 2002). Increasing the number of
supermarkets in areas where they are currently unavailable or where availability is limited is one
way to increase access to healthy foods, particularly for economically disadvantaged
populations.
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Provide incentives to food retailers to locate in and/or offer healthier
food and beverage choices in underserved areas
Limited availability of healthier food and beverage choices in underserved communities poses a
significant barrier to improving nutrition and preventing obesity (Morland, Wing, & Diez Roux,
2002). Local governments can offer financial and nonfinancial incentives to food retailers (e.g.,
grocery stores) to open new stores and/or to offer healthier food and beverage choices in areas
with few healthy food options. Financial incentives include, but are not limited to, tax breaks, tax
credits, loans, loan guarantees, and grants to cover start-up and investment costs. Nonfinancial
incentives include supportive zoning, negotiation assistance, and capacity building for small
businesses that want to initiate sales of healthier foods and beverages.
Improve availability of mechanisms for purchasing foods from farms
Farmers markets, farm stands, community-supported agriculture (CSA), pick your own, and
farm-to-school initiatives are all ways to purchase food from farms. Increasing the availability of
such mechanisms for purchasing foods from farms may reduce costs of fresh foods through
direct sales, increase the availability of fresh foods in areas without supermarkets, and improve
the nutritional value and taste of fresh foods by harvesting produce at ripeness rather than at a
time conducive to shipping (M. Hamm, personal communication, May 19, 2008).
Provide incentives for the production, distribution, and procurement of
foods from local farms
Increasing the production, distribution, and procurement of food from local farms might expand
the capacity of the food system to produce sufficient quantities of healthier foods and to improve
food security within local communities.
Restrict availability of less healthy foods and beverages in public service
venues
Research has shown that the availability of less healthy foods in schools is inversely associated
with fruit and vegetable consumption and is positively associated with fat intake among students
(Kubik, Lytle, Hannan, Perry, & Story, 2003). Schools can restrict the availability of less healthy
foods by setting standards for the types of foods sold, restricting access to vending machines,
banning snack foods and food as rewards in classrooms, or prohibiting food sales at certain times
of the school day. Other public service venues that can restrict the availability of less healthy
foods include afterschool programs, regulated child care centers, community recreational
facilities (e.g., parks, swimming pools), city and county buildings, and prisons and juvenile
detention centers.
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Institute smaller portion size options in public service venues
Research has documented a relationship between food portion sizes and energy intake (Kral &
Rolls, 2004; Rolls, Roe, & Meengs, 2006). Portion size is the amount (e.g., weight, calorie
content, or volume) of a single food item served in a single eating occasion. Local governments
can regulate food portion sizes served within public service venues such as regulated child care
centers, community recreational facilities (e.g., parks, recreation centers, playgrounds, and
swimming pools), city and county buildings, and prisons and juvenile detention centers.
Limit advertisements of less healthy foods and beverages
Television advertising influences children to prefer and request high-calorie and low-nutrient
foods and beverages and influences consumption among children between the ages of 2 and 11
years (IOM, 2006). Legislation to limit advertising of less healthy foods and beverages is usually
introduced at the Federal or State level. However, local governing bodies, such as district-level
school boards, might have the authority to limit advertisements of less healthy foods and
beverages in areas within their jurisdiction (Joint Center for Political and Economic Studies and
PolicyLink, 2004).
Discourage consumption of sugar-sweetened beverages
Consumption of sugar-sweetened beverages (e.g., carbonated soft drinks, sports drinks,
flavored/sweetened milk, and fruit drinks) among children has increased dramatically since the
1970s and is associated with higher daily caloric intake and greater risk of obesity among
children and adolescents (CDC,2006). Schools and group day care centers contribute to the
problem by serving and/or allowing children to purchase sugar sweetened beverages. Policies
that restrict the availability of sugar-sweetened beverages and 100% fruit juice in schools and
group day care centers may discourage the consumption of sugar-sweetened beverages among
children.
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Increase support for breastfeeding
Research has shown that breastfeeding provides a significant degree of protection against
childhood obesity (IOM, 2005). Despite the advantages of breastfeeding, many women who
work outside the home must bottle-feed their babies because their work setting does not provide
time or private space to breastfeed or to pump breast milk. State and local governments can offer
incentives to private businesses to accommodate breastfeeding among employees; they can also
set policies that require government facilities to support breastfeeding among female employees.
Require physical education in schools
Evidence suggests that school-based physical education (PE) increases students’ level of
physical activity and improves physical fitness (Zaza, Briss, & Harris, 2005). The National
Association for Sport and Physical Education (NASPE) and the American Heart Association
(AHA) recommend that “all elementary school students should participate in at least 150 minutes
per week of physical education, and all middle and high school students should participate in at
least 225 minutes of physical education per week, for the entire school year” (NASPE & AHA,
2006, p. 2). Although school administrators express concerns that PE classes compete with
traditional academic curricula, the Task Force for Community Preventive Services found no
evidence that time spent in PE classes harms academic performance (Zaza et al., 2005)
Reduce screen time in public service venues
When children spend too much time watching television and playing video games, they have less
time for physical activity and they can be exposed to advertising of unhealthy foods and
beverages (Hancox, Milne, & Poulton, 2004; Viner & Cole, 2005). The American Academy of
Pediatrics recommends that children spend no more 2 hours per day watching television
(American Academy of Pediatrics, 2001). State and local policymakers have an important role in
limiting screen time for children in schools, day care centers, and afterschool programs.
Improve access to outdoor recreational facilities
Recreation facilities provide space for community members to engage in physical activity and
include places such as parks and green space, outdoor sports fields and facilities, walking and
biking trails, public pools, and community playgrounds. Access to recreation facilities is affected
by proximity to homes or schools, cost, hours of operation, and transportation. Improving access
to outdoor recreation facilities may increase physical activity among children and adolescents.
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Enhance infrastructure supporting bicycling and walking
Research shows a strong and significant association between bicycling infrastructure and
frequency of bicycling for both recreational and commuting purposes (Dill & Carr, 2003;
Staunton et al., 2003). Infrastructure that supports bicycling includes bike lanes, shared-use
paths, bike routes on existing and new roads, and bike racks in the vicinity of commercial
and other public spaces. Local governments have a vital role to play in developing and
maintaining bicycling infrastructure for local residents.
Walking is a basic form of transportation and can be an important source of daily physical
activity. However, walking can be difficult for residents when communities lack sidewalks,
footpaths, walking trails, and safe pedestrian street crossings. Local governments play a key role
in shaping community infrastructure to support walking by promoting transit, community
planning, and zoning provisions, and by retrofitting existing areas to better serve pedestrians.
Support locating schools within easy walking distance of residential
areas
Improve access to public transportation
Walking to and from public transportation can help individuals attain recommended levels of
daily physical activity (Besser & Dannenberg, 2005). Public transportation includes mass transit
systems such as buses, light rail, street cars, commuter trains, and subways, and the infrastructure
supporting these systems (e.g., transit stops and dedicated bus lanes). Improving access to public
transportation may help promote more active lifestyles.
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Participate in community coalitions or partnerships to address obesity
Community coalitions consist of public- and private-sector organizations working together with
individual citizens to achieve a shared goal through the coordinated use of resources, leadership,
and action. The effectiveness of community coalitions stems from the multiple perspectives,
talents, and expertise that are brought together to work toward a common goal. Local
governments have critical perspectives and resources to share with community coalitions aiming
to prevent obesity by improving the local food and physical activity environment.
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7. Conclusion
To reverse the obesity epidemic, we must change our physical and food environments to
provide more opportunities for people to eat healthy foods and to be physically active on a daily
basis.
Experience points to the importance of several key elements, notably: high-level political
leadership; a structure for multi-sectorial collaboration within government and the effective
engagement of social and community actors; policies to address the food environment and,
timely monitoring and evaluation of population levels of overweight and obesity, dietary risk
factors, levels of physical activity and the impact over time of policies and intervention.
Facilitating factors include adequate and sustainable funds, timely engagement of experts, and an
emphasis on the development of functions, roles and competencies within the wider public health
workforce to drive through implementation.
The government has a focal role in providing a broad range of population-level actions. In
Europe a wide range of population-wide policies and initiatives including policies influencing
food environments and systems, physical activity environments and social marketing campaigns
are currently being promoted and implemented.
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U.S. Department of Health and Human 2. Services. 2008 Physical Activity Guidelines for
Americans. Washington (DC): U.S. Department of Health and Human Services; 2008.
Rideout VJ, Foehr UG, Roberts DF. Generation of M2 Media in the Lives of 8-18 Year
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Infants, Toddlers, Preschoolers, and Their Parents. Menlo Park, CA: The Henry J.
Kaiser Family Foundation; 2006.
Zimmerman FJ, Bell JF. Associations of television content type and obesity in
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Robinson TN. Television viewing and childhood obesity. Pediatr Clin North
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Active Living by Design. (2006). Partnership between local school district and county
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Brownell K, Farley T, Willett W, et al. The public health and economic benefits of taxing
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