This paper was presented at the Association for Education in Journalism and
Mass Communication in San Antonio, Texas August 2005.
If you have questions about this paper, please contact the author
directly. If you have questions about the archives, email
rakyat [ at ] eparker.org. For an explanation of the subject line,
send email to
[log in to unmask] with just the four words, "get help info aejmc," in the
body (drop the "").
Role of Media in Childhood Obesity
Mass Communication Theory & Methodology Division
AEJMC 2005 Convention
August 10-13, San Antonio, Texas
The role of media in childhood obesity:
A look from mass communication perspectives
Ph.D. Student, UNC-CH University Fellow
School of Journalism and Mass Communication
University of North Carolina at Chapel Hill
Campus Box 3365
Chapel Hill, NC 27599
[log in to unmask]
Recent years have witnessed the rapid increase in obesity among
American children. Obesity research has been done mostly by scholars
in health-related fields. Although there is a wealth of studies
regarding the role of media in childhood obesity, most of them
address only one or two aspects of the relationships and none has
given a panorama to the issues. Moreover, few studies are guided by
media effects theories. This paper explicates key concepts related to
childhood obesity, synthesizes the existing literature in the area,
and links media effect theories to the research findings for
explanation and prediction purposes. It attempts to serve as a brief
but comprehensive map for new explorers from mass communication perspectives.
The role of media in childhood obesity:
A look from mass communication perspectives
Recent years have witnessed the rapid increase in obesity among
American children. According to the U.S. Centers for Disease Control
and Prevention (CDC), since 1980 the proportion of overweight
children aged 6-11 has more than doubled, and the rate for
adolescents (ages 12-19) has tripled (CDC, 2004a, online). The
rising rates of childhood obesity pose a significant public health
challenge for us. While there are many causes of the problem,
children's media use and media effects on children are important
pieces of the puzzle – during the same period in which childhood
obesity has increased so drastically, there has been an explosion in
media targeted to children: TV shows and advertisement, specialized
cable networks, video games, and internet Websites. Along with this
media explosion, children spend more and more time with media and
logic suggests that, the more media exposure, the greater effect on children.
Obesity research has been done mostly by scholars in health-related
fields. Although there is a wealth of studies regarding the role of
media in childhood obesity, most of them address only one or two
aspects of the relationships and none has given a panorama to the
issues. Moreover, few studies are guided by media effects theories.
As the role of media in childhood obesity has aroused increasing
concerns, more and more mass media researchers have taken part in
childhood obesity research, although it is relatively a new ground
for them. By explicating key concepts, synthesizing the existing
literature in the area, and linking media effects theories to the
research findings for explanation and prediction purposes, this study
attempts to serve as a brief but comprehensive map for new explorers
from mass communication perspectives.
Defining Childhood Obesity
Although a variety of definitions of childhood obesity are in use,
and no commonly accepted standard has yet emerged, the body mass
index (BMI) is most widely used to indicate obesity, as it is the
tool recommended by U.S. Centers for Disease Control and Prevention
to screen for overweightness in children (CDC, 2004a, online). BMI is
calculated as weight in kilograms divided by the square of height in
meters (kg/m2). Since children's body fatness changes over the years
as they grow (see Figure on left for example, source from CDC, 2004b,
online), and girls and boys differ in their body fatness as they
mature, BMI for children must be age and gender specific and is
referred to as "BMI-for-age", which is plotted on gender specific
growth charts released by CDC (CDC, 2004b, online). The CDC
classifies children as "overweight" or "obese" if they are above the
95% percentile for their age and gender, and "at risk of being
overweight" or "at risk of obesity" if they are between the 85% and
95% percentile. Children who have from the 5th up to the 85th
percentile are considered having an acceptable weight (see Table 1).
< 5th percentile
At risk of obesity
85th – 95th percentile
> 95th percentile
BMI is used widely because of the relative ease and accuracy of the
basic measurements. Besides BMI, other measurements, such as skinfold
thickness, and percentage body fat, have been used as dependent
variables to assess childhood obesity. Percentage body fat is
considered an ideal measurement for obesity but is impractical to
measure, as it is less easy to obtain (Cole, Bellizzi, Flegal, &
Dietz, 2000). It can be estimated from densitometry or from total
body water converted to fat-free mass (FFM). For boys, risk of
overweight is usually defined as _20%Fat and the presence of
overweight is defined as _25%Fat; for girls, the cutoff for risk of
overweight is _25%Fat and that for presence of overweight is _30%Fat
(Malina & Katzmarzyk, 1999). As for skinfold thickness, some
researchers maintain that it is more sensitive and reliable in
measuring obesity than BMI, and obesity should be defined as a tricep
skinfold equal to or greater than the 85th percentile, and
superobesity defined as a tricepts skinfold equal to or greater than
the 95th percentile for children or adolescents of the same age and
gender (Dietz and Gortmaker, 1985).
In an attempt to evaluate the validity of BMI as an indicator of the
risk and presence of childhood obesity, Malina and Katzmarzyk (1999)
applied the aforementioned reference and cutoff values to several
ethnically diverse samples, with use of triceps skinfold thickness
and estimated percentage body fat as the criteria for obesity,
finding that BMI has high specificity, high efficiency, but low and
variable sensitivity. "Allowing for the ease of measuring height and
weight in the field setting, the BMI is an acceptable and valid
indicator of the risk of overweight and the presence of overweight in
adolescents" (p. 136S).
National BMI reference data are now available in many countries, and
the definitions of "at risk of obesity" (BMI _ 85%) and "obesity"
(BMI _ 95%) are widely used and recommended. In recent years, some
scholars have attempted to achieve a uniform international reference
data system for international comparison. It seems, however, the rush
to use a universal definition of childhood obesity is premature and
impractical (Reilly, 2002). By now, those countries that do not have
their own national BMI reference data usually use U.S. CDC standard
for reference, as it is recommended by the World Health Organization
for international comparison.
The Role of (Mass) Media
The role of media is not a monolithic concept. Instead, several
decades of media research and literature have made it a composite
concept consisting of several dimensions, including type of media,
media use, media content, media influence, and the cause-effect
process. The role of media has been a central concept in the
empirical school of mass communication research ever since the early
days of the field. Much of the inquiry has been focused on whether
the media have any effect, how much effect, which medium (e.g.,
newspaper or television) has effect on what aspect (e.g., perception
of reality) of the audience, or under what conditions or
circumstances may the effect occur.
Media and Childhood Obesity
The role of media in childhood obesity has drawn significant
attention from researchers from a variety of disciplines, including
medical sciences, public health, child development, advertising, and
mass media. Although the vast majority of the relevant literature
comes from health-related fields, some attention has been given from
a media perspective. Pediatricians, child development experts,
nutritionists, and media researchers have examined the role of media
in childhood obesity in one or more of the following aspects: (a)
What is the relationship between the amount of time children spend
using media and childhood obesity? Can reducing children's media use
time result in weight loss? (b) What is the relationship between
children's media use and their physical activities? Does children's
media use time displace their time spent on physical activities? (c)
What is the effect of media on children's eating behaviors? To what
extent are children influenced by food advertising to make food
choices? What is the food content in food ads and non-ads media
programs? Does unhealthy food prevail over healthy food?
Media use time and obesity
A simple way to find out the role of media in childhood obesity
would be to link obesity directly to the amount of time spent using
media. Such attempts have been included in most of the research on
A vanguard work, study analyzed a large data set from a national
survey of more than 13,000 American children, the National Health
Examination Survey (NHES), finding a significant association between
the amount of time children spent watching television and the
prevalence of obesity: among children aged 12 to 17, the prevalence
of obesity increased by 2% for each additional hour of television
viewing, controlling for other variables such as race and
socio-economic status. Since then, several more large-scale national
studies have also discovered such a correlation between media use and
body weight. use data from the 1988 to 1994 waves of the National
Health and Nutrition Examination Surveys (NHANES) to explore the
relationship between TV watching and obesity among boys and girls
aged 8 to 16, finding that both boys and girls who watch 4 or more
hours of TV have more body fat and greater body mass index (BMI) than
those who watch less than 2 hours per day. Another study using the
1988-1994 NHANES data discovers that TV watching time is positively
associated with obesity among girls .
As cross-sectional studies, like the aforementioned, cannot reveal
causal relationships, some researchers use longitudinal or
experimental methods, which are commonly considered more appropriate
ways to demonstrate cause and effect. conducted a randomized
controlled trial in which the amount of time a group of 3rd and 4th
graders spent with TV, videos, and video games was reduced and the
other group's was controlled. The intervention involved a "turnoff"
period of no screen time for 10 days, followed by limiting TV time to
7 hours per week as well as learning selective viewing. At the end
of a 6-month curriculum, students who received the intervention
achieved statistically significant reductions in their television
viewing and meals eaten in front of a TV set, as well as decreases in
BMI, triceps skinfold thickness, waist circumference, and
waist-to-hip ratio. longitudinal study is another example of an
attempt to demonstrate a causal relationship. In this study,
preschoolers are enrolled and followed into early
adolescence. Findings suggest that TV watching is an independent
predictor of the change in the child's BMI, and the researchers
conclude that children who watch the most television during childhood
have the greatest increase in body fat over time.
Media use and physical activity
The role of media in childhood obesity can be complicated, and
linking obesity directly to media use time may oversimplify the
situations. As common knowledge suggests that physical activity is
closely associated with health, some researchers pay more attention
to the relationship between children's media use and their physical
Based on a "zero-sum" assumption, it is logical to assume that an
increase in time spent using media means a decrease in time spent on
physical activities. Contrary to such an assumption, however, most
relevant research finds weak or no significant relationship between
media use time and physical activity time. In other words, the time
children spend using media does not necessarily displace their time
spent in physical activities. For instance, Anderson et al.'s (1998)
large-scale NHANES study finds no relationship between TV viewing
time and the number of bouts of vigorous physical activity. Another
study of a small sample of preschool children conducted in Texas
finds a weak relationship between TV viewing and physical activity .
Media effect, dietary habits, and nutrition conception
The fact that most studies have not discovered a significant
relationship between children's media use time and their physical
activity (energy expenditure) time calls for deeper thoughts. It
appears that media use time only, as a predictor, cannot explain
obesity in the sense that it displaces children's time spent on
physical activity. Since food (energy intake) is another primary
contributor to health, researchers reason, based on media effect
theories, that the food-related content in media that children are
exposed to may be an important factor in obesity.
Since children, compared to adults, are assumed much more susceptible
to media exposure, some researchers contend that food-related
programming content and food advertising have a powerful effect on
children's food choices and eating behaviors. manipulated
advertising shown to children aged 5 to 8 at a summer camp, with one
group viewing ads for fruit and juice and the other for candy and
Kool-Aid, finding that children's food choices are significantly
affected by which ads they saw. A more recent study finds that
students in grades 7-12 who watch more TV than other students tend to
frequently eat fast food . Some researchers assert that food ads may
also lead to children's misconceptions of the healthy versus
unhealthy food. A number of studies have supported such an
assertion. For instance, show a group of 4th and 5th graders a
series of paired food items and asked them to choose the healthier
item from each pair, for example, corn flakes or frosted flakes.
Findings indicate that children who watch more TV are more likely to
choose the less healthy food choice as opposed to the healthy one.
In summary, media may play an important role in childhood
obesity. First, the majority of relevant research finds a link
between the amount of time children spend watching TV and their body
weight or body mass index. Secondly, because no significant
displacement relationship has been found between children's media use
and physical activity, it is reasonable to suspect that children's
dietary habits, another primary factor leading to health, is affected
by media. In fact, a considerable part of the relevant literature has
answered such a question by finding that food-related content in
media, both programming and commercials, has significant associations
with children's food preferences, conceptions of healthy food, and
their eating behaviors.
The Cultivation Role of Media
Children's media exposure typically begins with television. Most
children start watching television before they learn to read. As
children have fewer external sources for information about the
reality, it is logical to presume that television viewing is highly
related to children's conceptions about the world (Gerbner, Gross,
Morgan, Signorielli, & Shanahan, 2002; Signorielli & Staples, 1997).
In other words, in terms of dietary habits, media could powerfully
affect children's conceptions of nutrition, food choices, and eating
Cultivation analysis represents a set of theoretical and
methodological assumptions and procedures designed to assess the
long-term contribution that television viewing makes to people's
conceptions of social reality (Gerbner, Gross, Morgan, Signorielli, &
Shanahan, 2002; Signorielli & Morgan, 1990). This theoretical
orientation is concerned with the more general and pervasive
consequences of cumulative exposure to cultural media such as
television, rather than how individual messages, programs, or even
genres of programs may produce immediate change in audience attitude
and behaviors. Over the past decades, although the perspective and
body of cultivation theory have been subject to criticism, the fact
remains that cultivation studies continue to find a positive relation
between watching more television and having conceptions about the
world that reflect the images seen on television (Signorielli & Morgan, 1996).
The theory of cultivation states that television has become people's,
and increasingly children's, most common and constant learning
environment, because its centralized mass production and routine use
of a coherent set of images and messages are produced and appeal to
the entire population – its socially constructed version of reality
bombards all classes, groups, and ages with the same perspectives
(Signorielli & Morgan, 1996). Television has its ability to
standardize, streamline, amplify, and share with virtually all
members of society the common cultural norms, and therefore, is the
"wholesale distributor of images that form the mainstream of our
popular culture" (p. 114).
Media content is the core element in cultivation process. Cultivation
analysis generally begins with identifying and assessing the most
recurrent and stable patterns in television content. This stage is
indispensable because hypotheses concerning television contribution
to viewers' conceptions about social reality cannot be formulated
without reliable information on the images and portrayals media
present. Much cultivation research has provided empirical support for
the assumption that there are many critical discrepancies between the
real world and the "world as portrayed on television", in other
words, the TV world is a distorted reflection of the real world.
Although they often match dominant ideologies and values, the shape
and profiles of the television world rarely match "objective reality"
(Signorielli & Morgan, 1996, p.120). For example, an early
cultivation study finds that television drama tends to "sharply
under-represent older people," although those over 65 constitute a
rapidly growing segment of the U.S. population (Gerbner, Gross,
Morgan, Signorielli, & Shanahan, 2002, p. 51). One of the most
examined aspects of television content in cultivation analysis is sex
or gender role stereotyping. Many studies have found that women are
underrepresented and that most television characters are extremely
gender-typed (Signorielli & Morgan, 1996).
With certain media content patterns identified and assessed,
cultivation theory then contends that those who spend more time
"living" in the world of television are more likely to give the
"television answer" – they see the "real world" in terms of the
images, values, portrayals, and ideologies that emerge through the
lens of television. More specifically, cultivation analysis
investigates whether the differences in the attitudes, beliefs, and
actions of light and heavy viewers reflect difference in their
viewing patterns and habits, independent of, or in interaction with
the social, cultural, and personal factors that differentiate light
and heavy viewers (Signorielli & Morgan, 1996; Gerbner, Gross,
Morgan, Signorielli, & Shanahan, 2002). For example, studies have
found considerable support for the proposition that heavy exposure to
the world of television cultivates exaggerated perceptions of the
number of people involved in violence in any given week, as well as
numerous other inaccurate beliefs about crime and law enforcement
(Gerbner, Gross, Morgan, Signorielli, & Shanahan, 2002). One example
of this is the "mean world syndrome." Researchers have found that
long-term exposure to television, in which frequent violence is
virtually inescapable, tends to cultivate the image of a relatively
mean and dangerous world – responses of those heavier compared to
lighter viewers suggest the conception of reality in which greater
protection is needed, most people "cannot be trusted," and most
people "just look out for themselves" (Gerbner, Gross, Morgan,
Signorielli, & Shanahan, 2002, p.52). Some researchers also tested
the hypothesis that television can affect reality perceptions because
people simply forget that what they see on TV is not real (Mares,
1996). Findings indicate that those who tended to confuse fiction
programs for reality see the world as a meaner, more violent, and
also are more likely to give "TV answers" to questions about social
Mainstreaming and resonance are two of the "after-the-fact" processes
that explain the cultivation effect of media. "Mainstreaming" means
that heavy viewing may absorb or override differences in perspectives
that ordinarily develop from other factors and influences (Gerbner,
Gross, Morgan, Signorielli, & Shanahan, 2002). As a process,
mainstreaming represents the theoretical elaboration and empirical
verification of the assertion that television cultivates common
perspectives (Signorielli & Morgan, 1996). "Resonance" means that the
congruence of the television world and real-life circumstances may
resonate and lead to significantly amplified cultivation patterns
(Signorielli & Morgan, 1996). In other words, heavy television
viewers who have experienced physical violence, for example, get a double dose.
In short, the theory of cultivation attempts to understand and
explain the dynamics of media as a distinctive feature of the modern
age. Designed mainly for television and focusing on its pervasive and
recurrent patterns of representation, cultivation analysis examines,
proves, and explains the enduring and common consequences of growing
up and living with television, in other words, the cultivation of
stable, resistant, and widely shared assumptions, images, and
conceptions reflecting the institutional characteristics and
interests of the medium itself and the larger society (Gerbner,
Gross, Morgan, Signorielli, & Shanahan, 2002; Signorielli & Morgan,
1990; Signorielli & Morgan, 1996).
The Cultivation Role of Media in Childhood obesity
Most Americans under 45 began watching television before they could
read or probably even speak (Signorielli & Morgan, 1996). Children
today spend an average of five and a half hours per day using media,
the equivalent of a full time job, and more time than they spend
doing anything else except for sleeping (Roberts & Foehr, 2004).
According to the principles of cultivation theory, in terms of
dietary habits, media could powerfully affect children's conceptions
of nutrition, food choices, and eating behaviors.
Food-related media content
Media content is determinant in the cultivation effect. Previous
research has found evidence that the food-related content in media is
unbalanced and misleading. First, much research has found that the
majority of commercials during children's programming promote foods
with low nutritional value, including candy, soft drinks, sugared
cereals, potato chips, and other high-salt, high-fat snacks. For
example, as cited in Signorielli and Lears (1992), Gerbner, Gross,
Morgan and Signorielli's (1981a) analysis of prime time and weekend
daytime commercials finds that food adverting accounts for more than
one quarter of such commercials; food-related activities occurred in
over 40% of commercials; sweets, snacks, and junk foods make up
nearly half of food commercials.
Another study assembles data from seven sites across the U.S.
representing a diverse range of medium-to-large television markets,
content analyzes the children programs in the seven sampled program
sources, such ABC, CBS, and NBC . A significant difference was found
in this study between the proportion of healthy food ads and the
unhealthy proportion - snacks and drinks make up 18.4% of all ads,
fast food ads make up 5.7%, whereas the healthy food category makes
up only 2.8% .
Kotz and Story's (1994) study assesses the TV commercials in
children's Saturday morning programming, finding that high-sugar
cereals were the most advertised food product, and other highly
advertised items include food rich in fat and sugars, most of which
had low nutritional value. They conclude that, given the findings of
this study, it is evident that food advertising aimed at children
attempts to persuade children to adopt eating patterns contrary to
the principles of national dietary recommendations.
Byrd-Bredbenner and Grasso (1999) studied the commercials in
prime-time programs most often watched by 2- to 11-year-olds and
found that 89% of food and beverage advertisements focused on taste,
convenience, and low cost; only 10% of the ads used nutrition or
health factors alone to sell the products. A later study of
Byrd-Bredbenner and Grasso (2000) content analyzes and compares the
advertisements broadcasted in 1992 and 1998 to create a description
of the health information conveyed in top-rated, prime time network
television advertisements, finding that the foods most intensely
advertised tend to be the ones overconsumed relative to the Dietary
Guidelines for Americans and other dietary recommendations; the
intake of soft drinks, a heavily advertised food on television, tends
to be inversely correlated with milk consumption, a food almost never
advertised on television; intake of fruits and vegetables is lower
than the recommended amounts.
study analyzes the trend in television advertising targeted to
children, and compares results to the historical perspective of the
last quarter century. Based on the Food Guide Pyramid and USDA Child
Nutrition criteria, they evaluate the advertising content of the 16
videotaped hours of Saturday morning children's programming on 4
network channels, finding that 63% of the 353 commercials analyzed
are for food products and the overall nutritional quality of
commercials remains poor, promoting a high-fat, low-fiber diet. The
study concludes that children's television food advertising continues
to send inappropriate nutrition messages, with no improvement noted
in 25 years.
Misleading messages about food, however, are not only found in
commercials. Paying attention to non-ad media programs, several
studies compare the nutritional value of food servings in TV shows
with the established recommended nutritional guidelines. For
instance, another analysis conducted by Gerbner, Gross, Morgan and
Signorielli (1981b) finds that prime time nutrition portrayal was
anything but balanced: in a week-long sample of prime time and
weekend daytime children's programming broadcast, eating, drinking,
or talking about food occurred about nine times per hour; grabbing a
snack was virtually as frequent as breakfast. study content analyzes
the sampled top-ranked prime time shows, finding that food references
occur almost 5 times per 30 minutes, 60% of which are for
low-nutrient beverages such as coffee, soft drinks, and
alcohol. This study also finds that snacks make up 72% of the food
references, the vast majority of which tend to be sweet and salty, in
other words, unhealthy. A third finding of this study is that
characters in the analyzed programs eat more between-meal snacks than
regular meals and food consumption stultifies social and emotional
needs more often than hunger. Byrd-Bredbenner, Finckenor, and
Grasso's (2003) study identifies, content analyzes, and describes the
health-related content (HRC) presented in the top-ranked prime-time
network programs for the age 2 to 11 year-old category. Results
reveal that viewers see one HRC-containing scene approximately every
four minutes; foods and alcoholic beverages are frequently shown and
consumed; in most scenes, the HRC portray negative health behaviors.
With the food-related media content analyzed and understood, numerous
studies have revealed the relation between exposure to food-related
media content and children's food preferences and nutritional
knowledge with ample empirical evidence. Positive relationships
between heavy television viewing and poorer nutrition knowledge have
been found, even controlling for other factors that might be related
to either heavy viewing or low knowledge, such as parent education,
child's reading level, and socio-economic status; heavy television
viewing and/or more-frequent exposure to low-nutrition foods also is
found related to children' preference for unhealthy foods and to poor
eating habits (Brown & Wash-Childers, 2002).
Several of these studies were conducted in the tradition of
cultivation analysis, with the assumption that television dominates
the symbolic environment of children's life. These studies sought to
ascertain if there is a relationship between television viewing and
having views of the world that are more reflective of the images seen
on television than those in fact. From the perspective of
cultivation theory, Signorielli and Lears (1992) examined children's
conceptions about nutrition as revealed in their answers to survey
questionnaires. Two hypotheses were tested: 1. The relation between
watching television and having poor eating habits is positive; 2. The
relation between watching television and having unhealthy conceptions
about food and the principles of nutrition is positive. In operation,
"watching television" was measured by "daily television-viewing
time." There were two sets of questions in the survey related to
eating habits (e.g., "how often do you eat a snack each day?") and
conception about food and nutrition (e.g., "which of the following is
the best example of a nutritious breakfast, a glass of orange juice
and a bowl of cereal with milk, three pancakes and three pieces of
cinnamon toast, or a glass of apple juice and two pieces of toast?"),
the children's answers to which were combined into an additive index
as measurement for the "eating habits" variable and the "conception
of nutrition" variable. A strong positive relation was found between
watching more television and giving answers to these questions that
reflect poor knowledge of nutrition, and having bad eating habits
(e.g., eating sugared cereal for breakfast, frequently eating at a
fast food restaurant, frequently eating sugared or fat-laden salty
snacks, and frequently drink soda or sweetened fruit drinks). To shed
further light on the relation between watching more television and
children's conceptions about nutrition, Signorielli and Staples
(1997) expanded and replicated the 1992 study, finding that the more
television the children watched the more likely they were to select
an unhealthy food when choosing which foods they would rather eat,
which is consistent with cultivation theory assertions.
Alternative Explanations of the Role of Media in Obesity
As cultivation theory has its weaknesses, such as overgeneralizing
media audience, and overgeneralizing media content, the theories of
social learning and priming can offer complement explanations for the
media effects on childhood obesity.
According to social learning theory (Bandura, 2002), children learn
by observing the behavior of others and the outcomes of those
behaviors; one major source of observed behavior is the mass media,
specifically television; media characters who serve as models may be
attended by children and, depending whether their eating behaviors
are rewarded or punished, they would either disinhibit or inhibit
children's imitation of the behavior respectively.
According to the theory of priming (Roskos-Ewoldsen, Roskos-Ewoldsen,
& Dillman-Carpentier, 2002), media, whose ubiquitous nature in
people's lives makes it a powerful tool for priming how they think
and believe, influences their later judgments and behavior. As
applied from the field of cognitive and social psychology to the
media, priming refers to the effects of the media content on people's
later behavior or judgments related to the content. For example,
media can prime aggressive thoughts and feelings, aggressive
behaviors, the information and criteria that people use in making
judgments of political figures, and various stereotypes that
influence how people make judgments of other people from the
stereotypes group (Roskos-Ewoldsen, Roskos-Ewoldsen, &
Dillman-Carpentier, 2002). In other words, the food-related content
in media can powerfully influence children's later conceptions and
judgments of food and nutrition, and their eating behavior.
No individual research works so far, however, were found from the
literature to study the role of media in childhood obesity from
either a social learning or priming perspective.
Hypotheses, Model, and Future Research
In accordance with previous childhood obesity studies and cultivation
theory principles, the role of media in childhood obesity can be
hypothesized as the followings:
H1: The more time children spend using media, the greater their BMI
H2: There is a negative relationship between children's amount of
time spent using media and amount of time they spend on physical activity.
H3: Children who spend more time with media are more likely to have
H4: Children who spend more time with media have less healthy dietary habits.
What is worth noting is that the existing literature on the topic has
mostly examined television only when dealing with media as a
contributor to obesity. Few studies have paid attention to the
computer screen. In fact, since 1995, the so-called "year of the
Internet," the Internet has revolutionized people's lives in many
aspects. In addition, playing computer games is popular among
children. By now, the computer screen is by no means a less
significant role than television screen in children's daily
life. Considering television only cannot reflect the reality
sufficiently. It is necessary, therefore, to take Internet and
computer games into account in our research. Does the computer
screen have a similar role in childhood obesity as television
screen? Do children nowadays spend more time on computer than on
television? Is there a relationship between children's computer use
time and their physical activity time? Are children who spend more
time on TV, computer games, and the Internet more likely to have
unhealthy dietary habits and nutrition misconception? Future research
should combine the Internet, computer games with television,
constituting new definitions of media use and effect concepts. For
example, "amount of time spent using media" means "amount of time
spent on the Internet, computer games, AND watching television".
As a conclusion of previous research, and a guide for future
research, a diagram of the hypothetical model for the role of media
in childhood obesity is hereby presented:
Andersen, R. E., Crespo, C. J., Bartlett, S. J., Cheskin, L. J., &
Pratt, M. (1998). Relationship of physical activity and television
watching with body weight and level of fatness among children:
Results from the Third National Health and Nutrition Examination
Survey. Jama-Journal of the American Medical Association, 279(12), 938-942.
Bandura, A. (2002). Social cognitive theory of mass communication. In
J. Bryant and D. Zillmann (Eds.), Media Effects: Advances in Theory
and Research (2nd ed. pp. 453-488). Mahwah, NJ: Lawrence Erlbaum
Borzekowski, D. L. G., & Robinson, T. N. (2001). The 30-second
effect: An experiment revealing the impact of television commercials
on food preferences of preschoolers. Journal of The American Dietetic
Association, 101(1), 42-46.
Brown, J., & Walsh-Childers, K. (2002). Effects of media on personal
and public health. In J. Bryant and D. Zillmann (Eds.), Media
Effects: Advances in Theory and Research (2nd ed. pp. 453-488).
Mahwah, NJ: Lawrence Erlbaum Associates, Inc.
Byrd-Bredbenner, C., & Grasso, D. (1999). Prime-time health: An
analysis of health content in television commercials broadcast during
programs viewed heavily by children. International Electronic Journal
of Health Education,2(4), 159-169.
Byrd-Bredbenner, C., & Grasso, D. (2000). Health, medicine, and food
messages in television commercials in 1992 and 1998. Journal of
School Health, 70(2), 61-65.
Byrd-Bredbenner, C., Finckenor, M., & Grasso, D. (2003). Health
related content in prime-time television programming. Journal of
Health Communication, 8, 329-341.
Centers for Disease Control and Prevention. (2004a). Over weight
among U.S. children and adolescents. National Health and Nutrition
Examination Survey. Retrieved September 18, 2004 from
Centers for Disease Control and Prevention. (2004b). BMI for children
and teens. Nutrition & Physical Activity. Retrieved September 16,
2004 from http://www.cdc.gov/nccdphp/dnpa/bmi/bmi-for-age.htm
Cole, T.J., Bellizzi, M.C., Flegal, K.M., & Dietz, W.H. (2000).
Establishing a standard definition for child overweight and obesity
worldwide: International survey. British Medical Journal, 320, 1-6.
Crespo, C. J., Smit, E., Troiano, R. P., Bartlett, S. J., Macera, C.
A., & Andersen, R. E. (2001). Television watching, energy intake, and
obesity in US children: Results from the Third National Health and
Nutrition Examination Survey, 1988-1994. Archives of Pediatrics &
Adolescent Medicine, 155(3), 360-365.
Dietz, W. H., & Gortmaker, S. L. (1985). Do we fatten our children at
the television set: Obesity and television viewing in children and
adolescents. Pediatrics, 75(5), 807-812.
Eisenmann, J. C., Bartee, R. T., & Wang, M. Q. (2002). Physical
activity, TV viewing, and weight in U.S. youth: 1999 youth risk
behavior survey. Obesity Research, 10(5), 379-385.
French, S. A., Story, M., Neumark-Sztainer, D., Fulkerson, J. A., &
Hannan, P. (2001). Fast food restaurant use among adolescents:
Associations with nutrient intake, food choices and behavioral and
psychosocial variables. International Journal of Obesity, 25(12), 1823-1833.
Gamble, M., & Cotugna, N. (1999). A quarter century of TV food
advertising targeted at children. American Journal of Health
Behavior, 23(4), 261-267.
Gerbner, G., Gross, L., Morgan, M., Signorielli, N. (1981a). Aging
with television commercials: Images on television commercials and
dramatic programming, 1977-1979. Unpublished manuscript, University
of Pennsylvania, The Annenberg School of Communication, Philadelphia.
(Cited from Signorielli & Lears, 1992).
Gerbner, G., Gross, L., Morgan, M., Signorielli, N. (1981b). Health
and medicine on television. New England Journal of Medicine, 305,
901-904. (Cited from Signorielli & Lears, 1992).
Gerbner, G., Gross, L., Morgan, M., Signorielli, N., & Shanahan, J.
(2002). Growing up with television: Cultivation processes. In J.
Bryant and D. Zillmann (Eds.), Media Effects: Advances in Theory and
Research (2nd ed. pp. 43-67). Mahwah, NJ: Lawrence Erlbaum Associates, Inc.
Goldberg, M. E., Gorn, G. J., & Gibson, W. (1978). TV messages for
snack and breakfast foods: Do they influence children's preferences?
Journal of Consumer Research, 5(2), 73-81.
Gorn, G. J., & Goldberg, M. E. (1982). Behavioral evidence of the
effects of televised food messages on children. Journal of Consumer
Research, 9(2), 200-205.
Kotz, K., & Story, M. (1994). Food advertisements during children's
Saturday morning television programming" Are they consistent with
dietary recommendations? Journal of American Dietetic Association,
Kunkel, D., & Gantz, W. (1992). Children's television advertising in
the multichannel environment. Journal of Communication, 42(3), 134-152.
Malina, R. M., & Katzmarzyk, R.T. (1999). Validity of the body mass
index as an indicator of the risk and presence of overweight in
adolescents. American Journal of Clinical Nutrition, 70 (suppl), 131S-6S.
Mares, M. (1996). The role of source confusion in television's
cultivation of social reality judgments. Human Communication
Research, 23(2), 278-297.
McCombs, M., & Reynolds, A. (2002). News influence on our pictures of
the world. In J. Bryant and D. Zillmann (Eds.), Media Effects:
Advances in Theory and Research (2nd ed. pp. 1-17). Mahwah, NJ:
Lawrence Erlbaum Associates, Inc.
Proctor, M. H., Moore, L. L., Gao, D., Cupples, L. A., Bradlee, M.
L., Hood, M. Y., & Allison, R. C. (2003). Television viewing and
change in body fat from preschool to early adolescence: The
Framingham Children's Study. International Journal of Obesity, 27(7), 827-833.
Reilly, J.J. (2002). Assessment of childhood obesity: National
reference data or international approach? Obesity Research, 10(8), 838-840.
Roberts, D., & Foehr, U. (2004). Kids & Media in America. Cambridge,
MA: University Press.
Robinson, T. N. (1999). Reducing children's television viewing to
prevent obesity: A randomized controlled trial. Jama-Journal of the
American Medical Association, 282(16), 1561-1567.
Roskos-Ewoldsen, D. R., Roskos-Ewoldsen, B., & Dilman-Carpentier, F.
R. (2002). Media priming: A synthesis. In J. Bryant and D. Zillmann
(Eds.), Media Effects: Advances in Theory and Research (2nd ed. pp.
453-488). Mahwah, NJ: Lawrence Erlbaum Associates, Inc.
Shrum, L. J. (2002). Media consumptions and perceptions of social
reality: Effects and undelying processes. In J. Bryant and D.
Zillmann (Eds.), Media Effects: Advances in Theory and Research (2nd
ed. pp. 69-95). Mahwah, NJ: Lawrence Erlbaum Associates, Inc.
Signorielli, N., & Lears. M. (1992). Television and children's
conceptions of nutrition: Unhealthy messages. Health Communication,
Signorielli, N., & Staples, J. (1997). Television and children's
conceptions of nutrition. Health Communication, 9(4), 289-301.
Signorielli, N., & Morgan, M. (1990). Cultivation analysis: New
directions in media effects research. Newbury Park, CA: Sage.
Signorielli, N., & Morgan, M. (1996). Cultivation analysis: Research
and practice. In M. B. Salwen & D.W. Stacks (Eds.), An integrated
approach to communication theory and research (pp. 111-125). Mahwah,
New Jersey: Lawrence Erlbaum Associates, Publishers.
Story, M., & Faulkner, P. (1990). The prime time diet: A
content-analysis of eating behavior and food messages in television
program content and commercials. American Journal of Public Health,
Wake, M. Hesketh, K., & Waters, E. (2003). Television, computer use
and body mass index in Australian primary school children. Journal of
Paediatr. Child Health, 39, 130-134.