Couch potatoes or french fries: are sedentary behaviors associated with body mass index, physical activity, and dietary behaviors among adolescents?

Parental influences on youth television viewing

OBJECTIVE

To assess associations among youth television (TV) viewing and parental TV viewing, parental knowledge of the American Academy of Pediatrics (AAP) recommendations to limit children's TV viewing time to < or = 2 hours per day (knowledge), and parental limits on the frequency of children's TV viewing (rules).

STUDY DESIGN

Adult participants in the 2002 Styles surveys answered questions about their weekly TV viewing, knowledge, and rules. TV viewing time of children of the adult participants (520 boys and 525 girls) age 10 to 18 years was also collected. Associations between hours of child TV viewing and parental TV viewing, parental knowledge, and parental rules were quantified using linear regression techniques.

RESULTS

Variables included in multivariate regression models accounted for 8% to 18% of the variance in TV viewing among boys and girls. Parent TV viewing was significantly associated with TV viewing in 10- to 12-year-old and 16- to 18-year-old boys and girls. Knowledge was not associated with TV viewing in boys and girls in this sample. Rules were associated with TV viewing in boys and girls of all ages.

CONCLUSIONS

Our findings suggest that parental TV viewing and rules limiting their child's TV time may play an important role in children's weekly TV viewing time.

Television viewing and exposure to food-related commercials among European school children, associations with fruit and vegetable intake: a cross sectional study

Background

Fruit and vegetable intake is low among European children and exposure to TV is negatively associated with the intake of fruit and vegetables. The aim of the present study was to explore exposure to food commercials on TV in nine European countries. Associations between such exposure and intake of fruit and vegetables and possible mediating effects of attitudes toward and liking of fruit and vegetables were assessed.

Methods

A cross-sectional survey was performed in nine European countries, i.e. Austria, Belgium, Denmark, Iceland, the Netherlands, Norway, Portugal, Spain and Sweden, from October-December 2003, as a part of the Pro Children study. Data on usual intake of fruit and vegetables, and related correlates were collected by means of a self-administered questionnaire among 11-year-old school children (mean age 11.4 (sd = 0.48), 50.2% boys). Complete data was available for 13,035 children. Differences in exposure to TV ads between countries, gender and social class were explored by analysis of variance. Multiple linear regression analysis was used to test associations between exposure to TV ads and intake and to assess mediating effects.

Results

The large majority of children in all nine countries report recent exposure to a number of TV ads for food, and they were more often exposed to ads for unhealthy food than for fruit and vegetables (mean of 2.2 (sd = 1.0) unhealthy ads vs. mean of 1.7 (sd = 1.0) healthy ads; p < 0.001). Boys reported somewhat higher TV viewing than girls did (2.5 (sd = 1.7) vs. 2.2 (sd = 1.6) hours per day; p < 0.001), and children from lower social classes reported higher TV viewing than higher social class children did (2.4 (sd = 1.7) vs. 2.0 (sd = 1.5); p < 0.001). Across all countries, exposure to TV ads for healthy foods was positively associated (r = 0.09–0.16) with reported fruit and vegetable intake. This association was in part mediated by attitudes toward and liking of fruit and vegetables.

Conclusion

Exposure to TV ads for fruit and vegetables appear to be associated with fruit and vegetable consumption among European school children. This relationship is in part mediated through cognitive factors such as attitudes and preferences concerning fruit and vegetables.

Snacking behaviours of adolescents and their association with skipping meals

Background

Snacking is likely to play an important role in the development of overweight and obesity, yet little is known about the contexts of snacking in adolescents or how snacking may influence other dietary habits, like meal skipping. This study examines the contexts in which adolescents snack and whether these contexts are associated with demographic characteristics of adolescents and with meal skipping.

Methods

A cross-sectional, self-reported online food habits survey was administered to 3,250 secondary students in years seven and nine. The students were drawn from 37 secondary schools in Victoria, Australia during 2004–2005. Frequencies of meal skipping, and snacking in eight contexts, were compared across gender, year level and region of residence. Logistic regressions were performed to examine associations between snacking contexts and meal skipping adjusting for gender and region.

Results

The most common contexts for snacking among adolescents were after school (4.6 times per week), while watching TV (3.5 times per week) and while hanging out with friends (2.4 times per week). Adolescents were least likely to snack all day long (0.8 times per week) or in the middle of the night (0.4 times per week). Snacking contexts were variously associated with gender, year level and region. In contrast, meal skipping was associated with gender and region of residence but not year level. Adolescents who reported more frequent snacking on the run, on the way to or from school, all day long, or in the middle of the night were more likely to skip meals.

Conclusion

These data suggest adolescents snack frequently, especially in their leisure time. In addition, adolescents who snack on the run, on the way to or from school, all day long or in the middle of the night are more likely to skip meals than are adolescents who don't snack at these times. Understanding the contexts in which adolescents snack, and their associations with skipping meals, may assist those involved in the promotion of healthy food habits among adolescents.

Physical activity and sedentary behaviors among Finnish youth

PURPOSE

There is general concern about the low level of physical activity and the high amount of time devoted to sedentary behavior among adolescents. This study aimed to determine the proportion of young Finns meeting the current guidelines for youth physical activity (>or= 60 min of moderate- to vigorous-intensity physical activity per day) and TV viewing (< 2 h.d(-1)) and to examine associations between physical activity and different sedentary behaviors.

METHODS

The study population consisted of 6928 boys and girls, members of the northern Finland birth cohort 1986 who, in 2001-2002, at age 15-16 yr, responded to a mailed questionnaire inquiring about their time spent in moderate to vigorous (MVPA), light (LPA), and commuting (CPA) physical activity, and different sedentary behaviors.

RESULTS

Fifty-nine percent of the boys and 50% of the girls reported 60 min or more of total physical activity per day. Only 23% of boys and 10% of girls reported 60 min of MVPA per day. Forty-eight percent of boys and 44% of girls reported more than 2 h of daily TV viewing. High amounts of TV viewing and computer use were associated with lower levels of physical activity in both genders.

CONCLUSION

Many adolescents exceeded the recommended level of TV viewing and did not meet current recommendations for health-related physical activity. The inverse associations of physical activity with TV viewing and computer use suggest that measures aimed to reduce sedentary behaviors may, at least partly, increase physical activity among youth.

Media use and obesity in adolescent females

OBJECTIVE

In the context of growing public health concern with the obesity rates among children and adolescents, much attention has focused on the role of television as a contributor to the problem. Less attention has been devoted to interactive media (internet surfing and video games), despite the fact that these forms of entertainment are fast gaining in popularity among youth. This study investigated the relative associations of TV viewing and interactive media use with body fat and BMI, controlling for both physical activity participation and cardiovascular fitness.

RESEARCH METHODS AND PROCEDURES

Female high-school adolescents (N = 194) were assessed for cardiovascular fitness (cycle ergometer), percent body fat (DXA), and BMI. Time spent in moderate, vigorous, and sedentary activities was assessed with a 3-day recall.

RESULTS

Multivariate regression analysis showed that only interactive media use was associated with percentage body fat and BMI, and the relationship remained strong even after controlling for physical activity participation and cardiovascular fitness.

DISCUSSION

It appears that, among this group of adolescent females, the association between interactive media use and obesity is not explained by a reduction in moderate or vigorous activity commensurate with media use.

Socioeconomic status and health behaviors in adolescence: a review of the literature

OBJECTIVE

The goal of this review was to determine the direction of associations between SES and health behaviors during the period of adolescence.

METHOD

We searched the PsychInfo and Pubmed databases for studies that measured the association between SES and cigarette smoking, alcohol consumption, marijuana use, diet, and physical activity in adolescents between 10- and 21-years old.

RESULTS

Associations between SES and health behaviors conformed to two patterns. First, low SES was associated with poorer diets, less physical activity, and greater cigarette smoking. Second, there was no clear pattern of associations between SES and alcohol consumption or marijuana use.

CONCLUSION

Results from this review indicate that, although some associations between SES and health behaviors exist during adolescence, the associations are not as robust as those in adulthood. Efforts to curb poor diet, inactivity, and smoking behaviors should target low SES adolescents, whereas efforts to curb teen drinking and marijuana use may be useful across the SES spectrum.

Measurement of television viewing in children and adolescents: a systematic review

The relationship between television (TV) viewing and overweight in children is likely to be influenced by the quality of measures used. We systematically reviewed studies related to overweight in children that had included a measure of TV exposure. Literature searches were conducted in MedLINE, PsychInfo, SportDiscus and ISIWeb of Science. Methods of assessing TV viewing were evaluated, including the type of measure, the administration procedure and reported psychometric properties. The majority of studies assessed TV viewing using self-report surveys and very few studies used direct observation. The validity or reliability of measures was often not examined. The majority of tools that were evaluated were compared with another self-report measure or an objective measure of physical activity. TV viewing measures should be selected that are specific to the research question, the study design, as well as methodological feasibility. However, it is recommended that measures of TV viewing be used only if they have psychometric data to support their validity and reliability. Selecting measures that are valid and reliable enables us to examine with greater accuracy the influence of TV viewing on childhood overweight, as well as the efficacy of interventions designed to reduce TV viewing in children.

Adolescent screen-viewing behaviour is associated with consumption of sugar-sweetened beverages: The role of habit strength and perceived parental norms

The association between adolescent screen-viewing behaviour (i.e., television viewing and computer use) and the consumption of sugar-sweetened beverages was studied in a Dutch sample of adolescents (N=383) using self-administered questionnaires. In particular, the previously understudied role of habit and perceived parental norms in the execution of these behaviours was investigated. Results showed that screen-viewing behaviour was associated with consumption of sugar-sweetened beverages (r=.32). Habit strength of both behaviours correlated with a large effect size (r=.50). The interaction between both behaviours was underlined by the finding that consumption of sugar-sweetened beverages was explained by perceived parental norms regarding screen-viewing behaviour (beta=.12; adjusted for the behaviour and perceived parental norm regarding sugar-sweetened beverage consumption). Consequences of the identified role of habit and parental norms in the interplay between sedentary behaviour and consumption of sugar-sweetened beverages among adolescents are discussed.

Are computer and cell phone use associated with body mass index and overweight? A population study among twin adolescents

Background

Overweight in children and adolescents has reached dimensions of a global epidemic during recent years. Simultaneously, information and communication technology use has rapidly increased.

Methods

A population-based sample of Finnish twins born in 1983–1987 (N = 4098) was assessed by self-report questionnaires at 17 y during 2000–2005. The association of overweight (defined by Cole's BMI-for-age cut-offs) with computer and cell phone use and ownership was analyzed by logistic regression and their association with BMI by linear regression models. The effect of twinship was taken into account by correcting for clustered sampling of families. All models were adjusted for gender, physical exercise, and parents' education and occupational class.

Results

The proportion of adolescents who did not have a computer at home decreased from 18% to 8% from 2000 to 2005. Compared to them, having a home computer (without an Internet connection) was associated with a higher risk of overweight (odds ratio 2.3, 95% CI 1.4 to 3.8) and BMI (beta coefficient 0.57, 95% CI 0.15 to 0.98). However, having a computer with an Internet connection was not associated with weight status. Belonging to the highest quintile (OR 1.8 95% CI 1.2 to 2.8) and second-highest quintile (OR 1.6 95% CI 1.1 to 2.4) of weekly computer use was positively associated with overweight. The proportion of adolescents without a personal cell phone decreased from 12% to 1% across 2000 to 2005. There was a positive linear trend of increasing monthly phone bill with BMI (beta 0.18, 95% CI 0.06 to 0.30), but the association of a cell phone bill with overweight was very weak.

Conclusion

Time spent using a home computer was associated with an increased risk of overweight. Cell phone use correlated weakly with BMI. Increasing use of information and communication technology may be related to the obesity epidemic among adolescents.

Associations between television viewing and consumption of commonly advertised foods among New Zealand children and young adolescents

OBJECTIVES

To explore how time spent watching television (TV) is associated with the dietary behaviours of New Zealand children and young adolescents.

DESIGN

Secondary data analysis of a nationally representative, cross-sectional survey.

SETTING

In homes or schools of New Zealand school students.

PARTICIPANTS

In total, 3275 children aged 5 to 14 years.

RESULTS

The odds of being overweight or obese increased with duration of TV viewing for children and adolescents when controlling for age, sex, ethnicity, socio-economic status and physical activity. Children and adolescents who watched the most TV were significantly more likely to be higher consumers of foods most commonly advertised on TV: soft drinks and fruit drinks, some sweets and snacks, and some fast foods. Both children and adolescents watching two or more hours of TV a day were more than twice as likely to drink soft drinks five times a week or more (P = 0.03 and P = 0.04, respectively), eat hamburgers at least once a week (both P = 0.02), and eat French fries at least once a week (both P < 0.01).

CONCLUSIONS

These findings suggest that longer duration of TV watching (thus, more frequent exposure to advertising) influences the frequency of consumption of soft drinks, some sweets and snacks, and some fast foods among children and young adolescents. Efforts to curtail the amount of time children spend watching TV may result in better dietary habits and weight control for children and adolescents. Future studies examining the impact of advertising on children's diets through interventions and international comparisons of legislation would provide more definitive evidence of the role of advertising in child and adolescent obesity.

Longitudinal and secular trends in physical activity and sedentary behavior during adolescence

OBJECTIVE

There is little epidemiologic research on longitudinal and secular trends in weight-related health behaviors throughout the stages of adolescence. In particular, few data are available to assess secular trends in various sedentary behaviors. The objective of this research was to investigate longitudinal and secular trends in physical activity and sedentary behavior in a large, diverse cohort of adolescents.

METHODS

Project EAT-II is a 5-year longitudinal study (N = 2516) that includes 2 cohorts that allow for the observation of longitudinal changes from early to midadolescence (junior high to high school; n = 806; mean baseline age: 12.8 +/- 0.8 years) and mid- to late adolescence (high school to post-high school; n = 1710; mean baseline age: 15.8 +/- 0.8 years). EAT-II also examined secular trends in health behavior from 1999 to 2004 in midadolescence. The main outcome measures of the mixed-model regression analyses used in this research were self-reported weekly hours of moderate to vigorous physical activity, television/video viewing, and leisure-time computer use.

RESULTS

Our findings indicate substantial longitudinal changes in moderate to vigorous physical activity, particularly among girls (decreasing 5.9-4.9 hours/week from early to midadolescence and 5.1-3.5 hours/week from mid- to late adolescence), and leisure-time computer use, particularly among boys (increasing 11.4-15.2 hours/week from early to midadolescence and 10.4-14.2 hours/week from mid- to late adolescence). Secular trends further indicate dramatic increases in midadolescent computer use from 1999 to 2004; girls increased from 8.8 to 11.1 hours/week, and boys increased from 10.4 to 15.2 hours/week.

CONCLUSIONS

These adolescents experienced unfavorable shifts in activity patterns, such as longitudinal decreases in moderate to vigorous physical activity, coupled with longitudinal and secular increases in leisure-time computer use. Developing effective health promotion strategies that address a wide array of changing behavioral patterns will be important in promoting long-term health and active lifestyles among adolescents and young adults.

Children's television viewing and objectively measured physical activity: associations with family circumstance

BACKGROUND

The contribution of family circumstance to physical activity and television viewing has not been widely investigated in pre-adolescents, and available information is inconsistent. This study examines whether television viewing and objectively measured physical activity vary by different indicators of family circumstance.

METHODS

Data from the 2001 Children's Leisure Activity Study and the 2002/3 Health, Eating and Play Study, involving Australian children in Grades Prep (mean age 6y) and 5-6 (mean age 11y), were combined. Children wore accelerometers for six consecutive 24 hour periods. Average min/day in low-intensity activity (1.0-1.9 METs) and moderate-to-vigorous-intensity activity (>or=3 METs) were calculated. Parents reported children's television viewing and family circumstance. Linear regression analyses were conducted separately for young girls, young boys, older girls and older boys.

RESULTS

Complete data were available for 2458 children. Parental education and, to a lesser extent, employment level were inversely associated with television viewing. Children in single-parent families, those whose fathers were not in paid employment, and those without siblings tended to spend more time in low-intensity activity than their peers. Children with siblings spent more time in moderate-to-vigorous-intensity activity; associations were stronger for girls. Maternal education was positively associated with moderate-to-vigorous-intensity activity for younger children. Maternal employment was positively associated with moderate-to-vigorous-intensity activity for older children. Multivariable models did not demonstrate a cumulative explanatory effect.

CONCLUSION

Individual measures of family circumstance were differentially associated with television, low-intensity activity and moderate-to-vigorous-intensity activity and associations were often not consistent across age-by-gender groups. Interventions may need to be tailored accordingly.

Childhood obesity: strategies for prevention

The incidence of overweight children aged between 6 and 11 years has more than doubled while the incidence for adolescents from age 12 to 19 has tripled between 1980 and 2000. The prevalence is highest among minorities and children belonging to low socioeconomic classes. Because overweight children tend to become obese adults, the future economic burden on the American healthcare system will be significant. This article examines the prevalence of the problem, highlights research and best practice models, and reviews policy trends related to childhood obesity.

Is love of nature in the US becoming love of electronic media? 16-year downtrend in national park visits explained by watching movies, playing video games, internet use, and oil prices

After 50 years of steady increase, per capita visits to US national parks have declined since 1988. This decline, coincident with the rise in electronic entertainment media, may represent a shift in recreation choices with broader implications for the value placed on biodiversity conservation and environmentally responsible behavior. We compared the decline in per capita visits with a set of indicators representing alternate recreation choices and constraints. The Spearman correlation analyses found this decline in NPV to be significantly negatively correlated with several electronic entertainment indicators: hours of television, (rs=-0.743, P<0.001), video games (rs=-0.773, P<0.001), home movies (rs=-0.788, P<0.001), theatre attendance (rs=-0.587, P<0.025) and internet use (rs=-0.783, P<0.001). There were also significant negative correlations with oil prices (rs=-0.547, P<0.025), foreign travel (rs=-0.452, P<0.05), and Appalachian Trail hikers (rs=-0.785, P<0.001). Income was significantly positively correlated with foreign travel (rs=0.621, P<0.005) but negatively correlated with national park visits (rs=-0.697, P<0.005). There was no significant correlation of mean number of vacation days, indicating available vacation time is probably not a factor. Federal funding actually increased during this period, and so was rejected as a probable factor. Park capacity was rejected as limiting since both total overnight stays and visits at the seven most popular parks rose well into the mid-1990s. Aging of baby boomers was also rejected as they are only now reaching retirement age, and thus during the period of visitation decline were still of prime family vacation age. Multiple linear regression of four of the entertainment media variables as well as oil prices explains 97.5% of this recent decline (r=0.975, multiple r2=0.950, adjusted multiple r2=0.925, SE=0.015, F=37.800, P<0.0001). We may be seeing evidence of a fundamental shift away from people's appreciation of nature (biophilia, Wilson 1984) to 'videophilia,' which we here define as "the new human tendency to focus on sedentary activities involving electronic media." Such a shift would not bode well for the future of biodiversity conservation.

Television viewing behaviour and associations with food habits in different countries

OBJECTIVE

Several environmental factors influence adolescents' food habits and television (TV) viewing is thought to be one of these factors. The purpose of the present study was to describe sociodemographic differences in TV viewing and to examine associations of TV viewing with the consumption of sweets, soft drinks, fruit and vegetables in different countries.

METHODS

Data were collected from 162,305 young people completing the 2001/02 Health Behaviour in School-Aged Children survey, a World Health Organization cross-national study on health and health behaviours among 11-, 13- and 15-year-old school pupils. Analyses of variance were used to examine sociodemographic differences in TV viewing and logistic regression analyses to examine associations between TV viewing and food habits.

RESULTS

Large differences were found between countries in reported daily TV viewing time, from an average of 2.0 h in Switzerland to 3.7 h in Ukraine. The results indicate that those most likely to watch TV are boys, 13-year-olds and pupils of lower socio-economic status. Those who watched more TV were more likely to consume sweets and soft drinks on a daily basis and less likely to consume fruit and vegetables daily, although the latter associations were not so apparent among Central and Eastern European countries.

CONCLUSIONS

Given the high TV viewing rates among adolescents and the association with less healthy food options, many young people are at increased risk of overweight or obesity. Interventions to modify TV viewing behaviour are needed. The findings underscore the importance of tackling socio-economic differences.

Determinants of fruit and vegetable consumption among children and adolescents: a review of the literature. Part I: Quantitative studies

BACKGROUND

In order to more effectively promote fruit and vegetable intake among children and adolescents, insight into determinants of intake is necessary. We conducted a review of the literature for potential determinants of fruit and vegetable intake in children and adolescents.

METHODS

Papers were identified from Medline and PsycINFO by using all combinations of the search terms: "fruit(s) or vegetable(s)" and "children or adolescents". Quantitative research examining determinants of fruit and/or vegetable intake among children and adolescents aged 6-18 years were included. The selection and review process was conducted according to a four-step protocol resulting in information on country, population, design, methodology, theoretical basis, instrument used for measuring intake, statistical analysis, included independent variables, and effect sizes.

RESULTS

Ninety-eight papers were included. A large number of potential determinants have been studied among children and adolescents. However, for many presumed determinants convincing evidence is lacking, mostly because of paucity of studies. The determinants best supported by evidence are: age, gender, socio-economic position, preferences, parental intake, and home availability/accessibility. Girls and younger children tend to have a higher or more frequent intake than boys and older children. Socio-economic position, preferences, parental intake, and home availability/accessibility are all consistently positively associated with intake.

CONCLUSION

The determinants most consistently supported by evidence are gender, age, socio-economic position, preferences, parental intake and home availability/accessibility. There is a need for internationally comparative, longitudinal, theory-based and multi-level studies taking both personal and environmental factors into account. This paper is published as part of the special Pro Children series in the International Journal of Behavioral Nutrition and Physical Activity. Please see [http://www.ijbnpa.org/content/3/1/26] for the relevant editorial.

Tackling the obesity pandemic: a call for sedentary behaviour research

An emerging threat to public health is seen in the dramatic rise in obesity status of Canadians, especially among young people. In addressing the possible factors responsible for these dramatic increases, this paper outlines the importance of understanding sedentariness as an important health behaviour, distinct from physical activity, and identifying the modifiable determinants of sedentary behaviours.

Urinary C-peptide excretion in free-living healthy children is related to dietary carbohydrate intake but not to the dietary glycemic index

This study first examined whether urinary C-peptide (UCP), stored at -20 degrees C, remains stable over the long term, and second, whether the dietary glycemic index (GI) and the glycemic load (GL: GI x g carbohydrates) are related to the 24-h UCP excretion of healthy children. Participants in the Dortmund Nutrition and Anthropometric Longitudinally Designed Study with 24-h urine collections and a simultaneously completed weighed dietary record were included. From these, 3 comparable groups of 7- to 8-y-old children (n = 40 each) from 1990, 1996, and 2002 were randomly selected (total n = 120). C-peptide was measured with a 1-site ELISA. A GI value was assigned to all recorded foods containing carbohydrates (CHO). Statistical equivalence tests corroborated that UCP excretion in the 3 sampling periods was equivalent when corrected for body weight and protein intake (P < 0.05). UCP excretion was associated with the GL after adjustment for body weight, protein, and fiber intake [mean UCP (95% CI) in GL tertiles 1-3: 6.19 (5.37, 7.14) vs. 7.82 (6.77, 9.02) vs. 7.76 (6.71, 8.97) nmol/d, P for difference 0.04]. GI was not significantly related to UCP excretion [adjusted means (95% CI): 7.27 (6.28, 8.41) vs. 6.51 (5.64, 7.51) vs. 7.94 (6.86, 9.18), P for difference 0.2]. In conclusion, UCP retrospectively measured with a 1-site ELISA remained stable for up to 12 y (from 1990 until 2002). The observed positive relation of UCP with GL appears to result largely from its association with the amount of CHO, whereas dietary GI may be relevant only at higher intake levels.

Does eating during television viewing affect preschool children's intake?

The objective of this study was to examine the effects of television (TV) viewing on children's lunch and snack intake in one condition when the children watched a 22-minute cartoon video on TV (TV group), and in another without the TV (no TV group). Participants included 24 children and their parents, recruited from a university child-care center. Parents reported children's TV viewing habits at home. Overall, children ate significantly less snack and lunch in the TV condition compared with the no TV condition. However, children who reportedly watched more daily hours of TV and who had a higher frequency of meals eaten in front of the TV at home ate more lunch in the TV condition. TV viewing may either increase or reduce children's intake, depending on prior experience with eating during TV viewing.

Preventing the broad spectrum of weight-related problems: working with parents to help teens achieve a healthy weight and a positive body image

A spectrum of eating-, activity-, and weight-related concerns is presented that includes 5 dimensions (weight control practices, level of physical activity, body image, eating behaviors, and weight status) and different levels of severity within each of these dimensions. Multiple interacting factors contribute to the etiology of problems within each of these dimensions in adolescents at the individual, familial, peer, school, community, and societal levels. Families have an important role to play in reinforcing the positive influences at each of these levels and in filtering out the negative influences. Parents can help their children engage in more healthful eating and physical activity behavior and feel better about themselves through (1) role modeling healthful behaviors, (2) providing an environment that makes it easy for their children to make healthful choices, (3) focusing less on weight and more on behaviors and overall health, and (4) providing a supportive environment for their children to enhance communication. Families need to be proactive within our society, which works against the development of a healthy weight and a positive body image in children and adolescents. However, families cannot do it on their own and need support from the more distal environments within which they function.

Psychosocial and environmental correlates of adolescent sedentary behaviors

OBJECTIVE

To determine correlates of sedentary behaviors in adolescents through the examination of psychosocial and environmental variables.

METHOD

The study used a cross-sectional design to evaluate an ethnically diverse clinic-based sample of 878 adolescents who were 11 to 15 years old. Bivariate and multivariate analyses were stratified by gender to assess correlates of sedentary behaviors occurring on the most recent nonschool day (television viewing, computer video games, sitting listening to music, and talking on the phone).

RESULTS

For girls, age, family support, television/video rules, and hills in the neighborhood were associated with sedentary behaviors. Furthermore, psychological constructs such as self-efficacy, enjoyment, change strategies, and pros and cons of change emerged as correlates of sedentary behaviors. A moderator effect revealed that the proportion of girls in the low-BMI group decreased with increased self-efficacy, whereas the proportion of girls in the high-BMI group did not vary significantly by self-efficacy. For boys, age, ethnicity, BMI, cons of change, and self-efficacy were associated with sedentary behaviors.

CONCLUSIONS

This study provides evidence of factors associated and not associated with adolescent sedentary behaviors. Similar to physical activity, measures of specific psychosocial constructs of sedentary behavior demonstrated important associations. The results highlight the need for additional examination of the correlates of sedentary behavior to determine which correlates are mechanisms of behavior change.

Changing impact of gastroesophageal reflux in medical and otolaryngology practice

OBJECTIVES/HYPOTHESIS

A major trend in gastroesophageal reflux disease (GERD) is an observed increased prevalence of the problem, with an associated burden on health care resources. There are relatively few objective reports of increasing prevalence of this disease, and there are no epidemiologic reports that discuss changing practice strategies in managing the disease. The clinical problem is of critical importance to practicing otolaryngologists, who manage the impact of GERD on diseases affecting the ear, nose, and throat. The hypothesis of this thesis is that 1) GERD is an increasing problem affecting outpatient office visits over time, and 2) the disease is increasingly managed with prescription pharmacotherapy.

STUDY DESIGN

Retrospective national medical database review using the National Ambulatory Medical Care Survey.

METHODS

Twelve years of data (1990-2001) were examined with visits weighted to provide U.S. estimates of care. Average annual frequencies and visit rates were calculated for total visits and by age, sex, race, and physician specialty. Selected issues in GERD treatment were also examined, including prescriptions and physician/patient counseling regarding stress management, tobacco abuse, and diet modification. Trends were reported based on changes in care across three time periods to satisfy statistical significance: 1990 to 1993, 1994 to 1997, and 1998 to 2001.

RESULTS

Between 1990 and 1993 and 1998 and 2001, there was a significant increase in U.S. ambulatory care visits for GERD, from a rate of 1.7 per 100 to 4.7 per 100. There were no significant changes in race, although there was a small trend toward increased GERD visits in the age group over 44 years old and in the male sex. Office visits to otolaryngologists increased from 89,000 to 421,000 between the time periods of 1990 to 1993 and 1998 to 2001. This also represented a percent increase in office encounters by otolaryngologists compared with visits by all specialties from 2.9% to 4.4%. Over the three time periods, there was a fall in prescriptions for histamine (H2) blockers from 58.1% to 20.7% of total prescriptions. Over the same three time periods, prescriptions of proton pump inhibitors increased from 13.2% to 64.6%. Physician recommendations for over the counter medications fell from 18.8% to 6.6%. Average annual counseling during ambulatory care visits for GERD was assessed for the period from 1998 to 2001 as follows: diet counseling was provided at 27.2% of encounters, tobacco cessation counseling was provided at 3.9%, and stress management was discussed at 3.9%.

CONCLUSIONS

During the 1990s, there was a substantial increase in the use of ambulatory care services for GERD. Although much of this increase was among the primary care community, otolaryngologists appeared to have an increasingly prominent role in the management of this disease. There have also been dramatic changes in physician prescribing patterns for GERD, with the emergence of the predominant role of proton pump inhibitors. However, the use of physician counseling for lifestyle modification of factors known to affect GERD remains very low. The increasing impact of GERD on physician practice emphasizes the importance of both physician and patient education in the delivery of health care related to this disease.

Role of fried foods and oral/pharyngeal and oesophageal cancers

We investigated the role of fried foods on oral-pharyngeal and oesophageal cancers, using data from two case–control studies conducted in Italy and Switzerland between 1992 and 1999, one with a total of 749 (634 men) cases of oral/pharyngeal cancer and 1772 (1252 men) controls, the other with 395 (351 men) cases of oesophageal cancer and 1066 (875 men) controls. Controls were admitted for acute, non-neoplastic conditions, unrelated to alcohol and smoking consumption. After allowance for sex, age, centre, education, body mass index, tobacco smoking, alcohol drinking and nonalcohol energy intake, the multivariate odds ratios (ORs) for an increment of one portion per week of total fried foods were 1.11 (95% confidence interval (CI): 1.05–1.17) for oral-pharyngeal and 1.16 (95% CI: 1.08–1.26) for oesophageal cancer. The ORs were consistent across strata of gender (OR in men only were 1.10 and 1.16, respectively), age, alcohol, tobacco consumption and body mass index.

BMI from 3–6 y of age is predicted by TV viewing and physical activity, not diet

OBJECTIVE

To investigate whether, diet, physical activity, sedentary behavior or television (TV) viewing predicted body mass index (BMI) among 3-7-y-old children.

DESIGN

A triethnic cohort of 3-4-y-old children was followed for 3 y from 1986 to 1989.

MEASUREMENTS

BMI was assessed at the beginning and end of each measurement year. Heart rate monitoring and observation were used to assess physical activity. Diet (calories, % calories from fat and carbohydrate), sedentary behavior and TV viewing were assessed by direct observation in each year. A repeated measures regression analysis with year as a factor and BMI at the end of each year as dependent variables was run. Nonsignificant variables were removed in a stepwise backward deletion process and significant interactions graphed.

RESULTS

The interactions between minutes of TV viewing per hour and study year and minutes of physical activity per hour and study year were significant (P<0.05). There were also significant main effects for TV viewing, physical activity and BMI from the beginning of the study. The model accounted for 65% of the variance in BMI across the three study years. Plotting the significant interactions demonstrated that physical activity was positively associated with BMI in year 1, and negatively associated in years 2 and 3 with a stronger negative relationship in year 3 than 2. TV viewing became positively associated with BMI during the third study year.

CONCLUSION

Physical activity and TV viewing were the only significant predictors (other than baseline BMI) of BMI among a triethnic cohort of 3-4-y-old children followed for 3 y with both physical activity (negatively associated) and TV viewing (positively associated) becoming stronger predictors as the children aged. It appears that 6 or 7 y is a critical age when TV viewing and physical activity may affect BMI. Therefore, focusing on reducing time spent watching television and increasing time spent in physical activity may be successful means of preventing obesity among this age group.