 |
|
Television Watching, Energy Intake, and Obesity in US Children
Results From the Third National Health and Nutrition Examination Survey, 1988-1994
Carlos J. Crespo, DrPH, MS;
Ellen Smit, PhD, RD;
Richard P. Troiano, PhD, RD;
Susan J. Bartlett, PhD;
Caroline A. Macera, PhD;
Ross E. Andersen, PhD
Arch Pediatr Adolesc Med. 2001;155:360-365.
ABSTRACT
| |
Objectives To examine the relationship between television watching, energy intake,
physical activity, and obesity status in US boys and girls, aged 8 to 16 years.
Methods We used a nationally representative cross-sectional survey with an in-person
interview and a medical examination, which included measurements of height
and weight, daily hours of television watching, weekly participation in physical
activity, and a dietary interview. Between 1988 and 1994, the Third National
Health and Nutrition Examination Survey collected data on 4069 children. Mexican
Americans and non-Hispanic blacks were oversampled to produce reliable estimates
for these groups.
Results The prevalence of obesity is lowest among children watching 1 or fewer
hours of television a day, and highest among those watching 4 or more hours
of television a day. Girls engaged in less physical activity and consumed
fewer joules per day than boys. A higher percentage of non-Hispanic white
boys reported participating in physical activity 5 or more times per week
than any other race/ethnic and sex group. Television watching was positively
associated with obesity among girls, even after controlling for age, race/ethnicity,
family income, weekly physical activity, and energy intake.
Conclusions As the prevalence of overweight increases, the need to reduce sedentary
behaviors and to promote a more active lifestyle becomes essential. Clinicians
and public health interventionists should encourage active lifestyles to balance
the energy intake of children.
INTRODUCTION
MORE US adults are overweight now than 20 years ago and the prevalence
of overweight among American children and adolescents is also increasing.1, 2, 3, 4, 5
Troiano et al3 reported on the trends of overweight
status using data from several national cross-sectional surveys of US children.
Overweight was defined by age- and sex-specific 85th and 95th percentiles
of body mass index (BMI) using data from cycles 2 (1963-1965) and 3 (1966-1970)
of the National Health Examination Survey (NHES). Using data from phase 1
(1988-1991) of the Third National Health and Nutrition Examination Survey
(NHANES III), they reported that the prevalence of overweight was 22% when
defined by the 85th percentile and 11% when defined by the 95th percentile.
A subsequent update using the data from both phases of NHANES III (1988-1994)
suggested that the increase in overweight prevalence had continued between
1991 and 1994.6
It is clear that obesity is detrimental to the health of adults, and
an increasing number of studies show that overweight children are at higher
risk of developing dyslipidemia, hypertension, diabetes mellitus, and other
weight-related morbidities.7, 8, 9, 10, 11, 12
Behavioral, environmental, and social factors in addition to a genetic predisposition
may be associated with a child becoming overweight. Other factors associated
with childhood obesity include time spent in front of a television or computer
monitor, availability of facilities for participation in physical activities,
and the opportunities to safely engage in sports, play, and exercise.13, 14, 15, 16, 17, 18, 19, 20
Since children are in a continuous state of physical growth, their energy
needs in relation to body weight are difficult to study in large epidemiologic
studies. Changes in energy intake in 2 large population-based studies show
that even though the reported total energy and fat intake has not increased
substantially in England or the United States in the last decade, the number
of overweight persons has increased in both countries.1, 21, 22
Neither the contribution of declining physical activity or increasing sedentary
behavior to the apparent positive energy balance23, 24, 25
nor the association between energy intake and sedentary behaviors using a
national representative sample of US children has been established.
In this article, we investigate the association between obesity, sedentary
behavior, and energy intake among children and adolescents. The purpose of
this study is to examine how the prevalence of obesity is associated with
physical activity, television watching, and energy intake using a national
representative sample of US children aged 8 through 16 years.
PARTICIPANTS, MATERIALS, AND METHODS
The NHANES III was conducted by the National Centers for Health Statistics
of the Centers for Disease Control and Prevention, Atlanta, Ga. This survey,
as in previous NHES and NHANES, was designed to provide national reference
data for a variety of diseases, chronic conditions, and health indicators
of the population of the United States and selected subpopulations. A detailed
explanation of NHANES III has been previously described.26
Briefly, NHANES III is a nationally representative sample of the civilian,
noninstitutionalized population of the United States. It oversampled the very
young and the very old, blacks, and persons of Mexican ancestry to produce
reliable estimates of their health conditions.
The NHANES III consisted of a home interview and a detailed clinical
examination conducted in a mobile examination center. Our analytic sample
consists of 4069 children, aged 8 to 16 years, who completed the physical
activity questionnaire and the body measurement component at the mobile examination
center, and who also responded to a home interview. Those children who had
a proxy answer to the physical activity and television questions in the mobile
examination center were excluded from our analyses (N = 9). Interviewing staff
consisted of experienced persons, many of whom were of Hispanic origin and/or
were bilingual in English and Spanish. All staff attended yearly training
sessions to ensure maintenance of effective interviewing and body measurements
skills. Information on the respondent's race and ethnicity was used to classify
persons as non-Hispanic white, non-Hispanic black, or Mexican American. Age
was defined as the age in years at the time of the household interview.
Participating children were asked: "How many times per week do you play
or exercise enough to make you sweat or breathe hard?" These activities did
not exclude school-related involvements such as physical education. The interview
also included a question on the number of hours of television watched the
previous day. We estimated the percentage of children who reported being active
most days of the week as children who reported participating in physical activity
at least 5 times per week as recommended by the Surgeon General's Report on
Physical Activity and Health.27, 28
Participants were classified into 7 categories of physical activity from 1
or less time per week to 8 or more times per week.
Assessment of hours of television watched the previous day was obtained
during the home interview and again during the mobile examination center visit.
These 2 interviews were approximately 1 to 3 weeks apart. Television watching
may vary from day to day (2-day agreement:  = 0.10). We therefore used
the average of the 2-day television-watching recall to estimate the percentage
of children watching television for 1 hour or less, 2 hours, 3 hours, 4 hours,
and 5 or more hours per day.
Body composition was estimated using BMI, which is calculated as weight
in kilograms divided by the square of height in meters, since this is significantly
and positively related to percentage of body fat and total body fat in boys
and girls.29, 30, 31, 32, 33, 34, 35, 36
We used data from cycles 2 and 3 from the NHES to establish age- and sex-specific
cutoff points for the definition of obesity. Cycle 2 was conducted from 1963
to 1965 and examined children aged 6 to 11 years, while cycle 3 was conducted
from 1966 to 1970, and examined adolescents between the ages of 12 and 17
years. These 2 cycles of NHES provide the earliest national data for height
and weight between children and adolescents. We defined obesity as the 95th
percentile of BMI from data obtained during the NHES (1963-1970), which has
a high specificity for excess body fat in children.3, 4
As part of the examination, a trained diet technician obtained information
on food intake using a 24-hour dietary recall. The dietary interviewers used
the Dietary Data Collection system, which is an automated standardized interactive
dietary interview and coding system, and was specifically designed for NHANES
III by the Minnesota Nutrition Coordinating Center. Participants were asked
to report all foods and beverages consumed, excluding plain drinking water,
during the previous 24 hours, from midnight to midnight. The food database
for this system was linked to the US Department of Agriculture's (USDA) Survey
Nutrition Database and produced total energy intake.26
Statistical analyses were carried out using SAS, SUDAAN, and STATA.36, 37, 38 For NHANES III, sampling
weights were calculated taking into account the unequal probability of selection
resulting from the cluster design and from planned oversampling of certain
subgroups. All analyses incorporated the sampling weights. We used the svymean
estimation procedure in the STATA software to calculate the prevalence, SEs
and 95% confidence intervals, and the PROC RLOGIST from SUDAAN to calculate
estimated relative risk and the 95% confidence intervals.
RESULTS
Table 1 presents the cross-sectional
prevalence estimates of hours of television watched per day by sex, age, and
race/ethnicity among US children. Overall, almost half of US children aged
8 to 16 years watched more than 2 hours of television a day. More boys than
girls watched more than 2 hours of television (38% and 48%, respectively).
Among race/ethnicity groups, a higher percentage of non-Hispanic black (65%)
and Mexican American (53%) children watched television for 3 or more hours
than non-Hispanic white children (37%). On the average, 17% of non-Hispanic
black children watched 5 hours or more a day, whereas only 9% of Mexican American
and 6% of non-Hispanic white children watched television for 5 or more hours
a day.
|
|
|
|
Table 1. Prevalence (per 100) and 95% Confidence Intervals (CIs) of
Daily Television Watching Habits Among US Children Aged 8 to 16 Years, 1988
to 1994
|
|
|
Table 2 shows the prevalence
of obesity, total energy intake, and percentage of children who are active
5 or more days per week. Total energy intake was consistently higher among
boys than girls, regardless of age or race/ethnic groups. Boys reported being
more physically active than girls; however, only 56.7% of US children aged
8 to 16 years engage in physical activity 5 or more days per week. Non-Hispanic
white boys had the highest prevalence of participating in physical activity
5 or more days per week (72.4%), while non-Hispanic black girls had the lowest
prevalence of participating in physical activity 5 or more days per week (41.8%).
|
|
|
Table 2. Unadjusted Prevalence (per 100) of Obesity, Total Energy Intake,
and Percentage of Time Participating Most Days of the Week ( 5 Days) in
Physical Activity Among US Children Aged 8 to 16 Years, 1988 to 1994
|
|
|
Figure 1 shows the prevalence
of obesity among US children according to hours of television watched per
day. The prevalence of obesity increased as hours of television watching increased.
Obesity was lowest among children who reported watching 1 hour or less of
television per day. The prevalence of obesity according to weekly participation
in vigorous physical activity showed no clear trends for either boys or girls
(data not shown).
|
|
|
|
Figure 1. Prevalence of obesity by daily
hours of television watched among US children aged 8 to 16 years, from 1988
to 1994.
|
|
|
We subsequently examined whether television watching was related to
energy intake in boys and girls. Figure 2 shows adjusted energy intake by hours of television watching in
boys and girls. After adjusting for age, BMI, race/ethnicity, family income,
and weekly bouts of physical activity, we found that total energy intake was
positively associated with hours of television watched more so among girls
(R = 0.43) than among boys (R
= 0.26). The mean adjusted energy intake of girls who watched 1 hour or less
of television was 7748 kJ/d, whereas mean energy intake of girls who watched
5 or more hours of television a day was 8468 kJ/d. These results indicate
that energy intake has a tendency to increase with increased television watching,
especially when comparing those watching 1 hour or less of television and
those watching 5 or more hours a day.
|
|
|
|
Figure 2. Relationship between total daily
energy intake and daily hours of television watched among US children aged
8 to 16 years, from 1988 to 1994. Total energy intake was adjusted for age,
body mass index, race/ethnicity, family income, and weekly bouts of physical
activity. The P value measured the main effects in the model.
|
|
|
Table 3 shows the estimated
relative risk of obesity by hours of television watching after adjusting for
several correlates (eg, age, race/ethnicity, family income, energy intake,
physical activity). A higher prevalence of obesity was significantly associated
with higher television watching among girls. We found no consistent association
between prevalence of obesity and weekly bouts of vigorous physical activity.
|
|
|
|
Table 3. Association Between Obesity and Television Watching Among
US Boys and Girls Aged 8 to 16 Years, 1988 to 1994*
|
|
|
COMMENT
Our findings provide estimates of the distribution of television-watching
habits in US children aged 8 to 16 years and how television watching relates
to obesity. We found that increased television watching is associated with
a higher prevalence of obesity among girls, but not among boys. Children who
watched the most number of hours of television a day had the highest prevalence
of obesity; this held true after controlling for age, race/ethnicity, and
family income (Figure 1) (Table 3).
Boys (12.4%) exhibit a somewhat higher prevalence of obesity than girls
(10.9%). More alarming is the fact that the prevalence of obesity has more
than doubled in less than 1 generation. Using the age- and sex-specific 95th
percentile of BMI as the cutoff point from data collected between 1963 and
1970 NHES, our results indicate prevalence estimates of obesity to be greater
than 10%. If in 1963 through 1970, the top 5% were classified as obese, we
now have approximately 12% of US children in this category.
We found that energy intake has a tendency to increase with increased
television watching, with girls consuming on average an extra 732.2 kJ (175
kcal) a day when comparing those watching 1 hour or less of television with
those watching 5 or more hours a day. When taking into account that the hours
spent watching television represent hours doing little or no physical activity,39, 40 and the cumulative effect of these
extra 732.2 kJ (175 kcal) a day, the net result could be a positive energy
balance that may be linked to childhood and adult obesity.
Our finding that television watching was more closely associated with
obesity than physical activity may be partially explained by the lack of sensitivity
of the NHANES III questionnaire to accurately measure physical activity in
children. We must, therefore, be cautious in interpreting these results based
on one 24-hour dietary recall and 1 question on self-reported weekly bouts
of physical activity in this group of children, because of the substantial
intraindividual and interindividual variability. Thus, there is a possibility
that the associations we have observed with obesity may be attenuated because
of the unreliability of these measures.41, 42
In addition, the ability to accurately measure both physical activity and
television-watching habits are influenced by 2 factors. First, how well does
self-report of physical activity reflect what children and adolescents are
actually performing over the time frame that the question is being asked?
Second, can a single report of physical activity accurately represent the
usual physical activity patterns of children and adolescents? It may be that
multiple days of observation during the year, over several years, are needed
to reliably estimate the usual physical activity and television-watching patterns
of young children.
Boys reported engaging in more physical activity (66.7% are active 5
d/wk) than girls (46.1% are active 5 d/wk), and they consume more kilojoules
(10 506 kJ/d [2511 kcal/d]) than girls (7945 kJ/d [1899 kcal/d]). Boys
and girls may be different in how they deal with weight gain. For example,
we found more girls than boys, aged 12 to 16 years, reporting that they had
attempted to lose weight in the past 12 months (22.6% and 9.9%, respectively).
Our findings are similar to those of Steen et al,43
who found that the prevalence of overweight was not substantially different
between boys and girls. Other researchers have also found that despite the
high prevalence of obesity in boys, few of them reported trying to lose weight.43, 44, 45, 46, 47, 48
The boys perceived themselves as significantly less overweight and were happier
with their "looks" than girls. Also, girls seem to be less likely to think
of themselves as exercisers. More research is needed to understand how weight
loss practices and body image perceptions are related to energy intake, television
watching, and physical activity in boys and girls.
Previous studies have found an indirect association between these 2
behaviors (physical activity and television watching). DuRant et al24 assessed television watching and physical activity
by direct quantitative observation and its association with body composition
in 5- to 6-year-old children. As expected, children were less active during
their longest bout of television watching, while physical activity increased
in periods of low television watching. Correspondingly, the authors concluded
that children engage in more physical activity when they are not watching
television. We conducted a regression analysis to examine the relationship
between daily hours of television watching and weekly bouts of physical activity.
We found an inverse association between television watching and physical activity
for both boys (ß coefficient, -0.06; P
= .02) and girls (ß coefficient, -0.075; P
= .01). Although small, this correlation has been confirmed in other validity
studies among children.49
Our study is also limited to television watching and does not include
time spent on the computer. More research is needed to develop better tools
to assess physical activity and to assess time spent on the computer or playing
computer games in addition to just watching television. Another limitation
of our study is that our findings are cross-sectional and cannot distinguish
if high television watching causes obesity or if being obese causes children
to watch too much television. Our findings do confirm that the prevalence
of obesity has increased since 1963, and that energy intake in conjunction
with excess television watching and little physical activity may play a role.
CONCLUSIONS
Our results show that the prevalence of obesity is greater among children
who watch 4 or more hours of television a day. Our findings also show that
girls report engaging in less physical activity than boys, and provide support
for a major national campaign to promote reductions in sedentary behavior,
such as television watching, and to increase the opportunities for both boys
and girls to participate in lifetime physical activities. Sound dietary practices
and reductions in sedentary behavior may help in preventing further increases
in the prevalence of obesity of US children.
AUTHOR INFORMATION
Accepted for publication October 4, 2000.
From the School of Medicine and Biomedical Sciences, State University
of New York, Buffalo (Dr Crespo); Schools of Public Health (Dr Smit) and Medicine
(Drs Bartlett and Andersen), Johns Hopkins University, Baltimore, Md; National
Cancer Institute, National Institutes of Health, Bethesda, Md (Dr Troiano);
and the Division of Nutrition and Physical Activity, Centers for Disease Control
and Prevention, Atlanta, Ga (Dr Macera).
Corresponding author: Ross E. Andersen, PhD, Division of Geriatric
Medicine and Gerontology, The Johns Hopkins School of Medicine, 4940 Eastern
Ave, Suite 025, Baltimore, MD 21224 (e-mail: andersen{at}jhmi.edu).
Reprints:
Carlos J. Crespo, DrPH, MS, Department of Social and Preventive Medicine,
School of Medicine and Biomedical Sciences, State University of New York at
Buffalo, 270 Farber Hall, Buffalo, NY 14214-3000 (e-mail: ccrespo{at}buffalo.edu).
REFERENCES
| |
1. Kuczmarski RJ, Flegal KM, Campbell SM, Johnson CL. Increasing prevalence of overweight among US adults: the National Health
and Nutrition Examination Surveys, 1960 to 1991. JAMA. 1994;272:205-211.
ABSTRACT
2. Flegal KM, Troiano RP, Pamuk ER, Kuczmarski RJ, Campbell SM. The influence of smoking cessation on the prevalence of overweight
in the United States. N Engl J Med. 1995;333:1165-1170.
FREE FULL TEXT
3. Troiano RP, Flegal KM, Kuczmarski RJ, Campbell SM, Johnson CL. Overweight prevalence and trends for children and adolescents: the
National Health and Nutrition Examination Surveys, 1963 to 1991. Arch Pediatr Adolesc Med. 1995;149:1085-1091.
ABSTRACT
4. Kuczmarski RJ. Trends in body composition for infants and children in the US. Crit Rev Food Sci Nutr. 1993;33:375-387.
ISI
| PUBMED
5. Seidell JC. Obesity: a growing problem. Acta Paediatr Suppl. 1999;88:46-50.
PUBMED
6. Troiano RP, Flegal KM. Overweight children and adolescents: description, epidemiology and
demographics. Pediatrics. 1998;101:497-504.
FREE FULL TEXT
7. Simsolo RB, Romo MM, Rabinovich L, Bonanno M, Grunfeld B. Family history of essential hypertension versus obesity as risk factors
for hypertension in adolescents. Am J Hypertens. 1999;12:260-263.
FULL TEXT
|
ISI
| PUBMED
8. Daniels SR, Morrison JA, Sprecher DL, Khoury P, Kimball TR. Association of body fat distribution and cardiovascular risk factors
in children and adolescents. Circulation. 1999;99:541-545.
FREE FULL TEXT
9. Moran R. Evaluation and treatment of childhood obesity. Am Fam Physician. 1999;59:861-863.
ISI
| PUBMED
10. Sinaiko AR, Donahue RP, Jacobs DR Jr, Prineas RJ. Relation of weight and rate of increase in weight during childhood
and adolescence to body size, blood pressure, fasting insulin, and lipids
in young adults: the Minneapolis Children's Blood Pressure Study. Circulation. 1999;99:1471-1476.
FREE FULL TEXT
11. Moussa MA, Shaltout AA, Nkansa-Dwamena D, et al. Factors associated with obesity in Kuwaiti children. Eur J Epidemiol. 1999;15:41-49.
FULL TEXT
|
ISI
| PUBMED
12. US Department of Health and Human Services, National Institutes of
Health National Heart, Lung, and Blood Institute. Update on the Task Force Report on High Blood Pressure
in Children and Adolescents: A Working Group Report From the National High
Blood Pressure Education Program. Bethesda, Md: National Institutes of Health; 1996. NIH publication
96-3790.
13. Livingstone MB, Strain JJ, Prentice AM, et al. Potential contribution of leisure activity to the energy expenditure
patterns of sedentary populations. Br J Nutr. 1991;65:145-155.
FULL TEXT
|
ISI
| PUBMED
14. Okamoto E, Davidson LL, Conner DR. High prevalence of overweight in inner-city schoolchildren. AJDC. 1993;147:155-159.
15. Guo SS, Chumlea WC. Tracking of body mass index in children in relation to overweight in
adulthood. Am J Clin Nutr. 1999;70:145S-148S.
16. Guggenheim K, Poznanski R, Kaufmann NA. Attitudes of adolescents to their body build and the problem of juvenile
obesity. Int J Obes. 1977;1:135-149.
ISI
| PUBMED
17. Golan M, Fainaru M, Weizman A. Role of behaviour modification in the treatment of childhood obesity
with the parents as the exclusive agents of change. Int J Obes Relat Metab Disord. 1998;22:1217-1224.
FULL TEXT
|
ISI
| PUBMED
18. Thakur N, D'Amico F. Relationship of nutrition knowledge and obesity in adolescence. Fam Med. 1999;31:122-127.
PUBMED
19. Crisp AH, Stavrakaki C, Halek C, Williams E, Sedgwick P, Kiossis I. Smoking and pursuit of thinness in schoolgirls in London and Ottawa. Postgrad Med J. 1998;74:473-479.
ABSTRACT
20. Averett S, Korenman S. Black-white differences in social and economic consequences of obesity. Int J Obes Relat Metab Disord. 1999;23:166-173.
FULL TEXT
|
ISI
| PUBMED
21. Prentice AM. Obesity in Britain: gluttony or sloth? BMJ. 1995;311:437-439.
FREE FULL TEXT
22. McDowell MA, Briefel RR, Alaimo K, et al. Energy and Macronutrient Intakes of Persons Ages
2 Months and Over in the United States: Third National Health and Nutrition
Examination Survey, Phase 1, 1988-1991. Hyattsville, Md: National Center for Health Statistics; 1994:1-24.
Advance Data From Vital and Health Statistics, No. 255.
23. Bernard L, Lavallee C, Gray-Donald K, Delisle H. Overweight in Cree schoolchildren and adolescents associated with diet,
low physical activity, and high television viewing. J Am Diet Assoc. 1995;95:800-802.
FULL TEXT
|
ISI
| PUBMED
24. DuRant RH, Baranowski T, Johnson M, Thompson WO. The relationship among television watching, physical activity, and
body composition of young children. Pediatrics. 1994;94:449-455.
FREE FULL TEXT
25. Andersen RE, Crespo CJ, Bartlett SJ, Cheskin LJ, Pratt M. 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. 1998;279:938-942.
FREE FULL TEXT
26. National Center for Health Statistics, Centers for Disease Control
and Prevention. NHANES III Reference Manuals and Reports. Washington, DC: US Dept of Health and Human Services; 1996.
27. Pate R, Corbin C, Pangrazi B. Physical activity for young people: President's Council on Physical
Fitness and Sports. Res Digest. 1998;3:1-7.
28. US Department of Health and Human Services. Physical Activity and Health: A Report of the Surgeon
General. Atlanta, Ga: Centers for Disease Control and Prevention and National
Center for Chronic Disease Prevention and Health Promotion; 1996.
29. Strauss R. Childhood obesity. Curr Probl Pediatr. 1999;29:1-29.
PUBMED
30. Dietz W. Physical activity and childhood obesity. Nutrition. 1991;7:295-296.
ISI
| PUBMED
31. Cole TJ, Power C, Preece MA. Child obesity and body-mass index. Lancet. 1999;353:1188.
32. Widhalm K, Schonegger K. BMI: does it really reflect body fat mass? J Pediatr. 1999;134:522-523.
PUBMED
33. Malina RM, Katzmarzyk PT. Validity of the body mass index as an indicator of the risk and presence
of overweight in adolescents. Am J Clin Nutr. 1999;70(1, pt 2):131S-136S.
34. Guillaume M. Defining obesity in childhood: current practice. Am J Clin Nutr. 1999;70(suppl):126S-130S.
35. Dietz WH, Bellizi MC. Introduction: the use of body mass index to assess obesity in children. Am J Clin Nutr. 1999;70:123S-125S.
36. SAS Institute Inc. SAS/STAT User's Guide, Version 6. Cary, NC: SAS Institute Inc; 1989.
37. Shah BV, Barnwell BG, Bieler GS. SUDAAN User's Manual, Release 7.5. Research Triangle Park, NC: Research Triangle Institute; 1997.
38. STATA Corp. STATA User's Guide, Release 6. College Station, Tex: Stata Press; 1999.
39. Epstein LH, Valoski AM, Vara LS, et al. Effects of decreasing sedentary behavior and increasing activity on
weight change in obese children. Health Psychol. 1995;14:109-115.
FULL TEXT
|
ISI
| PUBMED
40. Robinson TN. Reducing children's television viewing to prevent obesity: a randomized
controlled trial. JAMA. 1999;282:1561-1567.
FREE FULL TEXT
41. Pate RR. Physical activity assessment in children and adolescent. Crit Rev Food Sci Nutr. 1993;33:321-326.
ISI
| PUBMED
42. Puhl J, Greaves K, Hoyt M, Baranowski T. Children's Activity Rating Scale (CARS): description and calibration. Res Q Exerc Sport. 1990;61:26-36.
ISI
| PUBMED
43. Steen SN, Wadden TA, Foster GD, Andersen RE. Are obese adolescent boys ignoring an important health risk? Int J Eat Disord. 1996;20:281-286.
FULL TEXT
|
ISI
| PUBMED
44. Perl MA, Mandic ML, Primorac L, Klapec T, Perl A. Adolescent acceptance of different foods by obesity status and by sex. Physiol Behav. 1998;65:241-245.
FULL TEXT
| PUBMED
45. White DR, Schliecker E, Dayan J. Gender differences in categorizing adolescents' weight status. Psychol Rep. 1991;68:978
FULL TEXT
|
ISI
| PUBMED
46. Rosen JC, Gross J. Prevalence of weight reducing and weight gaining in adolescent girls
and boys. Health Psychol. 1987;6:131-147.
FULL TEXT
|
ISI
| PUBMED
47. Nowak M, Speare R, Crawford D. Gender differences in adolescent weight and shape-related beliefs and
behaviour. J Paediatr Child Health. 1996;32:148-152.
ISI
| PUBMED
48. Felts WM, Parrillo AV, Chenier T, Dunn P. Adolescents' perceptions of relative weight and self-reported weight-loss
activities: analysis of 1990 YRBS (Youth Risk Behavior Survey) national data. J Adolesc Health. 1996;18:20-26.
FULL TEXT
|
|
