Role of television in childhood obesity prevention

Addressing childhood obesity through increased physical activity

Obesity is affecting an increasing proportion of children globally. Despite an appreciation that physical activity is essential for the normal growth and development of children and prevents obesity and obesity-related health problems, too few children are physically active. A concurrent problem is that today's young people spend more time than previous generations did in sedentary pursuits, including watching television and engaging in screen-based games. Active behavior has been displaced by these inactive recreational choices, which has contributed to reductions in activity-related energy expenditure. Implementation of multifactorial solutions considered to offer the best chance of combating these trends is urgently required to redress the energy imbalance that characterizes obesity. The counterproductive 'shame and blame' mentality that apportions responsibility for the childhood obesity problem to sufferers, their parents, teachers or health-care providers needs to be changed. Instead, these groups should offer constant support and encouragement to promote appropriate physical activity in children. Failure to provide activity opportunities will increase the likelihood that the children of today will live less healthy (and possibly shorter) lives than their parents.

Frequency and types of foods advertised on Saturday morning and weekday afternoon English- and Spanish-language American television programs

OBJECTIVE

To describe food advertised on networks serving children and youth, and to compare ads on English-language networks with ads on Spanish networks.

DESIGN

Analysis of television food advertisements appearing on Saturday morning and weekday afternoons in 2005-2006. A random sample of 1,130 advertisements appearing on 12 networks catering to Spanish-language, children, youth, Black youth, and general audiences were analyzed.

MAIN OUTCOME MEASURES

Each advertisement was coded for the nature of the item promoted, the selling propositions used, and any nutritional claims made.

ANALYSIS

Cross-tabulations using Fisher's exact test (P < .05 criterion).

RESULTS

One-fifth of commercials were for food. Food ads were especially prevalent on Saturday programs and children's networks. Seventy percent of food ads were for items high in sugar or fat. More than one fourth of food advertisements were for fast-food restaurants, which were especially common on MTV and Spanish-language networks. Ads for fruits and vegetables were rare (1.7%). One nutrition-related public service announcement was found for every 63 food ads.

CONCLUSIONS AND IMPLICATIONS

Food advertisements continue to promote less-healthful items. Until marketing of high calorie, low-nutrient food to children is restricted, education and media literacy remain the best strategies for mitigating advertising effects.

Changes in food advertisements during 'prime-time' television from 1991 to 2006 in the UK and Canada

Food advertisements on mainstream television have received less research attention than those on children's television. Little is known about how television food advertisements vary internationally or if there have been changes over recent years. We describe food-related television advertisements and the nutrient content of foods advertised during prime-time television in Ontario, Canada and the UK in 1991 and 2006. Information on what advertisements were broadcast were obtained from video recordings and audience research bureaux. Data on nutrient content of foods advertised were obtained from manufacturers and standard food tables. The proportion of advertisements that were food related decreased between 1991 and 2006 in both countries. The frequency of food-related advertisements was relatively constant in Canada but decreased between 1991 and 2006 in the UK. In 1991, advertisements for beverages and meals predominated in both countries. By 2006, food-related advertisements in Canada were dominated by meals and restaurants. In the UK advertisements for food stores and beverages predominated. The 'TV diet' in Canada in 1991 was relatively high in fat, high in alcohol and low in fibre, compared to current recommendations. By 2006, this had changed to high in fat and sodium and low in fibre. The 'TV diet' in the UK in 1991 was high in fat, sodium, sugar and alcohol and low in fibre compared to current recommendations. By 2006, the UK 'TV diet' was high in sodium, sugar and alcohol and low in fibre. Foods advertised on 'prime-time' television do not reflect a healthful diet.

Mealtime television viewing and dietary quality in low-income African American and Caucasian mother-toddler dyads

To examine maternal demographic characteristics and depressive symptoms as predictors of TV viewing during mealtimes, and to investigate how mealtime TV viewing predicts mothers' and toddlers' food consumption. A prospective, cross-sectional survey design was employed with 199 African American and 200 Caucasian, low-income, mother-toddler dyads enrolled in eight Early Head Start programs in a Midwestern state. Mothers completed the Toddler-Parent Mealtime Behavior Questionnaire to assess toddler mealtime behavior. Data were analyzed using a three-step multiple regression: (a) step one was to determine what characteristics predicted family TV viewing during mealtime; (b) step two was to determine whether TV viewing during mealtime predicted maternal food consumption, and (c) step three was to determine whether TV viewing during mealtime predicted toddler food consumption. Direct and indirect effects of TV watching were explored via path models. Maternal race, education, and depressive symptoms predicted 8% of the variance in TV viewing during mealtime (P < or = 0.001). African American mothers and mothers who had fewer years of schooling and exhibited more depressive symptoms tended to watch more TV during mealtime. More TV viewing during mealtime predicted mothers' intake of 'more' unhealthy foods. Mothers' food consumption was the single best predictor of toddlers' food consumption, while TV viewing during mealtime had an indirect effect through mothers' TV viewing. TV viewing practices affect mothers' food consumption and mealtime behaviors; this, in turn, impacts toddlers' food consumption. Practical interventions are needed to positively influence the nutritional habits of lower-income mothers. Reducing mothers' "unhealthy" food consumption while watching TV may offer one effective strategy.

Overweight in children and adolescents associated with TV viewing and parental weight: Project HeartBeat!

BACKGROUND

Parental obesity and TV viewing are risk factors for childhood obesity. This study assessed the association of children's TV viewing and computer use with body mass and examined whether parental weight status modified the association.

METHODS

Cross-sectional associations of parental weight status, hours of TV viewing and computer use, and children's body composition were studied in a subsample of 526 black and nonblack children, aged 8, 11, and 14 years at baseline, enrolled in Project HeartBeat!, a longitudinal study of cardiovascular disease risk factors, 1991-1995. BMI, fat-free mass (FFM), and percent body fat (PBF) were calculated from children's body composition measured at baseline. Children's TV viewing and computer use habits and parental height and weight were self-reported. Multivariate regression analysis was used in assessing inter-relations of parental weight status and child's TV viewing and computer use habits with BMI, FFM, PBF, and risk for overweight status (BMI > or =85th percentile), adjusting for age, gender, race, and Tanner stage.

RESULTS

Children of one or two overweight/obese parents watched an average of 22+/-6 minutes or 30+/-11 minutes more TV per day than children of normal-weight parents, respectively (both p<0.01). In multivariate regression analyses, BMI and PBF increased significantly by 0.42 kg/m(2) and 1.14% (both p<0.001), respectively, for each hour of TV watched among children with overweight parents, but not for those with normal-weight parents (p(interaction)<0.05). Similar results were observed for total screen time.

CONCLUSIONS

These study findings are consistent with a genetic contribution of parental weight; however, overweight/obese parents may also exhibit behavior patterns that negatively influence children's TV viewing and have an impact on child overweight status. The effect of parental BMI on children's BMI may have both a genetic and an environmental linkage.

Food-related advertising geared toward Mexican children

BACKGROUND

Overweight and obesity have dramatically increased in recent years. In 2006, the prevalence of overweight and obesity among 6- to 12-year-old children was 26% in Mexico. Food advertising has shown to be a contributor to childhood obesity. The purpose of this study was to evaluate the frequency and types of food advertisements geared toward children living in Baja California.

METHODS

Two local channels and three national channels, during a period of 7 h on weekday afternoons and 6 h on weekend mornings, were recorded for 7 days. A total of 235 h were recorded and analyzed.

RESULTS

A total of 8299 advertisements were registered; 22% were food-related and 50% were geared toward children. The average of food-related advertisements (FRAs) per half an hour was 4, and half of them were geared toward children. During the time that children may be watching television, 50% of all FRAs were potato and corn chips, desserts and cakes, juices, sweetened cereals, candies, cookies, sweetened beverages and fast foods, which comprises a higher percentage of adult-oriented FRA (32 versus 22%).

CONCLUSION

Children are systematically more exposed than adults to advertisements for high-energy-dense foods.

Objectively measured physical activity, physical activity related personality and body mass index in 6- to 10-yr-old children: a cross-sectional study

Background

The prevalence and level of overweight in childhood is rapidly increasing. One potential contributor to the rise in overweight is a decline in physical activity (PA). The purpose of this study was to compare levels and patterns of PA and PA related personality in normal-weight (NW) and overweight (OW) 6- to 10-yr-old children.

Methods

Subjects were grouped into OW (N = 59, BMI = 24.2 ± 4.8 kg/m²) or NW (N = 61, BMI = 15.7 ± 1.5 kg/m²) according to International Obesity Task Force cut-offs. PA was assessed by accelerometry. Parents filled in a questionnaire on PA and sedentary behaviour and PA related personality of their child (born tired, moves slowly, is often tired, lacks energy, avoids physical efforts, prefers watching playing children instead of joining them, is always active, needs to let himself/herself go, has a lot of energy).

Results

NW children spent on average 77 min/day in MVPA, whereas OW children only 57 min/day (p = .001). OW children had fewer 5, 10 and 20 min bouts of MVPA (p = .01). OW and NW children showed identical PA patterns on both week days and weekends, although at different levels. According to parents' report, a greater percentage of OW children was not engaged in any sport (46% versus 23%, chi² = 6.3, p = .01). OW children had a less active personality (p < .001), watched more TV during weekend (p < .01), but no differences were found in outside play or non-active play. BMI of mother and father explained 29% of the variance in children's BMI z-score (p < .001). PA related personality, screen behaviour during weekend and MVPA explained an additional 12% (p < 0.01).

Conclusion

The results of this study demonstrate that NW children spent on average 20 min per day more in MVPA. PA patterns were similar in NW versus OW children, although at different levels. Greatest differences in PA according to weight status were found in the afternoon during after school hours. This is the first study to show distinct PA related personality traits in OW children compared to NW peers.

Nutrition and body weights of Canadian children watching television and eating while watching television

OBJECTIVE

To examine whether eating while watching television poses a risk for poor nutrition and excess body weight over and above that of time spent watching television.

DESIGN

We analysed data of grade 5 students participating in a comprehensive population-based survey in the Canadian province of Nova Scotia. This survey included the Harvard's Youth Food Frequency Questionnaire, students' height and weight measurements, and a parent survey. We applied multivariable linear and logistic random effects models to quantify the associations of watching television and eating while watching television with diet quality and body weight.

SETTING

The province of Nova Scotia, Canada.

SUBJECTS

Grade 5 students (n 4966).

RESULTS

Eating supper while watching television negatively affected the consumption of fruits and vegetables and overall diet quality. More frequent supper while watching television was associated with more soft drink consumption, a higher percentage energy intake from sugar out of total energy from carbohydrate, a higher percentage energy intake from fat, and a higher percentage energy intake from snack food. These associations appeared independent of time children spent watching television. Both watching television and eating while watching television were positively and independently associated with overweight.

CONCLUSIONS

Our observations suggest that both sedentary behaviours from time spent watching television as well as poor nutrition as a result of eating while watching television contribute to overweight in children. They justify current health promotion targeting time spent watching television and call for promotion of family meals as a means to avoid eating in front of the television.

The clinical and laboratory assessment of the sleepy child

Excessive sleepiness is defined as sleepiness that occurs in a situation when an individual would usually be expected to be awake and alert. Hypersomnia is characterized by recurrent episodes of excessive daytime sleepiness (EDS) or prolonged nighttime sleep, which affects the everyday life of the patient. Clinical surveys have reported that EDS is a complaint observed in up to 68% of normal high school children, with a negative impact in academic achievement and extracurricular activity. Clues toward recognizing childhood daytime sleepiness may be sleeping longer hours than expected for age, daytime naps beyond normal for age, being sleepy when other children of the same age are active and alert, and sleeping more than previously. Causes of EDS are arbitrarily divided into 3 categories: insufficient nighttime sleep, fragmented nighttime sleep, and increased drive of sleep. A list of various causes of EDS in children has been discussed. A detailed history along with examination of the upper airway is crucial in evaluating patients with EDS. Appropriate screening tools such as sleep logs, sleepiness scales, and sleep questionnaires further help in identifying and quantifying the degree of sleepiness. Confirmatory tests such as polysomnography, multiple sleep latency test, and actigraphy along with referral to a sleep physician may be necessary in appropriate cases. Details of other ancillary testing such use of cerebrospinal fluid orexin levels, HLA subtyping, and so on have also been provided.

Lifestyle and Risk of Cardiovascular Disease and Type 2 Diabetes in Women: A Review of the Epidemiologic Evidence

Cardiovascular disease is the leading cause of death among both women and men in the United States, accounting for nearly half of all deaths and considerable morbidity. Type 2 diabetes is a major risk factor for cardiovascular disease and one that is particularly potent in women; its prevalence has increased dramatically in recent years. Epidemiologic data indicate that cardiovascular disease and type 2 diabetes share common risk factors and are largely preventable; indeed, findings from the Nurses' Health Study suggest that 74% of cardiovascular disease cases, 82% of coronary heart disease cases, and 91% of diabetes cases in women could be prevented by not smoking, engaging in regular physical activity, maintaining a healthy weight, eating healthier food, and drinking moderate amounts of alcohol. This article reviews lifestyle risk factors and preventive strategies for cardiovascular disease and type 2 diabetes among women.

A Review of Family Meal Influence On Adolescents’ Dietary Intake

Recent concerns about adolescent nutrition and unhealthy weights have prompted an examination of the myriad influences on dietary intake during adolescence. Included here are a summary of the literature on family influence on dietary intake, specifically during adolescence and within the family context, a summary of family meal patterns, and a systematic review of the known influences of family meals on dietary intake. Because of the complexity of families in today’s society, models were developed to depict the broad context of familial influences on adolescent nutritional behaviours and attitudes and to describe what is known and not known about family meal influences on adolescent dietary intake and quality. A systematic review of the literature revealed seven articles specifically related to adolescents, family meals, and dietary intake, which were analyzed for strength of evidence and plausibility. In spite of data collection methods relying on self-report, results suggested that family meals were associated with improved dietary intakes. Families in today’s societies are complex. Nevertheless, parents have the potential to influence positively, through family meals, what food is provided, where it is provided (e.g., home, restaurant), and within what type of atmosphere it is provided.

Associations between children's television advertising exposure and their food consumption patterns: A household diary–survey study

In a diary-survey study in 234 households with children aged 4-12 years, we investigated the associations between children's exposure to food advertising and their consumption of (a) advertised food brands, (b) advertised energy-dense food product categories, and (c) food products overall. Relations were examined using multiple hierarchical regression analysis, while controlling for various child (i.e., age, sex, television viewing time) and family variables (i.e., family income and consumption-related communication styles). Results showed that children's exposure to food advertising was significantly related to their consumption of advertised brands (beta=.21) and energy-dense product categories (beta=.19). The relation between advertising exposure and overall food consumption only held in lower-income families (beta=.19). In addition, consumption-related family communication was an important moderator of the relations between advertising and the food consumption variables. Socio-oriented family communication (i.e., striving for harmony and conformity) was particularly successful in reducing these relations. In conclusion, consistent with communication theories predicting spill-over effects of advertising, the impact of television food advertising exceeded the advertised brand and generalized to more generic unhealthy consumption patterns. Theoretical and societal consequences, as well as the important role of the family are discussed.

Primary prevention of childhood obesity: an interdisciplinary analysis

The primary prevention of childhood obesity requires combined efforts by stakeholders at various societal levels, based on the knowledge from multiple disciplines. The goal of the present study was therefore to analyze current preventive approaches and delineate implications for future prevention research and practice by integrating knowledge from genetics, law, economics, psychology, and social ethics. Inconclusive evidence on the etiology of obesity, a complex, multifactorial condition, likely complicates prevention, leading to a lack of specificity regarding target groups, focus, and techniques. It is recommended to increase the specificity of prevention by explicitly considering risk factor evidence, including evidence on genetic factors. Because the institutional and legal framework of primary obesity prevention in children is insufficient in many countries, considering the risk factors for childhood obesity is also crucial for establishing a basis for legal regulations. Companies from sectors concerned with food intake and physical activity may be involved in preventive action, e.g., for initiating self-defeating sanctions. Long-term behavior change may be enhanced through the systematic application of behavior modification techniques within primary prevention programs. Overall, an interdisciplinary perspective furthers understanding of the complexity of this condition and can inform public health strategies on the primary prevention of childhood obesity.

Stability of television viewing and electronic game/computer use in a prospective cohort study of Australian children: relationship with body mass index

Background

While much cross-sectional data is available, there have been few longitudinal investigations of patterns of electronic media use in children. Further, the possibility of a bi-directional relationship between electronic media use and body mass index in children has not been considered. This study aimed to describe longitudinal patterns of television viewing and electronic game/computer use, and investigate relationships with body mass index (BMI).

Methods

This prospective cohort study was conducted in elementary schools in Victoria, Australia. 1278 children aged 5–10 years at baseline and 8–13 years at follow-up had their BMI calculated, from measured height and weight, and transformed to z-scores based on US 2000 growth data. Weight status (non-overweight, overweight and obese) was based on international BMI cut-off points. Weekly television viewing and electronic game/computer use were reported by parents, these were summed to generate total weekly screen time. Children were classified as meeting electronic media use guidelines if their total screen time was ≤14 hrs/wk.

Results

Electronic media use increased over the course of the study; 40% met guidelines at baseline but only 18% three years later. Television viewing and electronic game/computer use tracked moderately and total screen time was positively associated with adiposity cross-sectionally. While weaker relationships with adiposity were observed longitudinally, baseline z-BMI and weight status were positively associated with follow-up screen time and baseline screen time was positively associated with z-BMI and weight status at follow-up. Children who did not meet guidelines at baseline had significantly higher z-BMI and were more likely to be classified as overweight/obese at follow-up.

Conclusion

Electronic media use in Australian elementary school children is high, increases with age and tracks over time. There appears to be a bi-directional association suggesting that interventions targeting reductions in either screen time or adiposity may have a positive effect on both screen time and adiposity.

Trends and sociocultural factors for childhood overweight in La Reunion Island

OBJECTIVE

To examine time trends (study 1) and sociocultural factors associated with childhood overweight (study 2) in La Reunion Island.

DESIGN

Study 1: a longitudinal analysis of anthropometric data available from health services in the town of Saint-Pierre. Study 2: a case - control study.

SUBJECTS

Study 1: 1753 children born between 1977 and 1996. Study 2: 101 six-year old overweight children sex-matched with 101 non-overweight children.

MEASUREMENTS

Study 1: overweight at birth (birth weight>4 kg) and at age 4 and 6 using French references and references from the International Obesity Task Force. Study 2: parental and perinatal data, child's lifestyle and representation of food, all collected from the mother.

RESULTS

Study 1: a dramatic increase in the prevalence rate of overweight at 4 and at 6 is observed, more severe in girls. Study 2: multivariate logistic regressions showed that mother's overweight was the only variable significantly associated with overweight in both the sexes. The other associated factors were related to sociocultural and family features and sedentarity. Logistic probability functions derived from these data are proposed as a tool for detection of at risk families.

CONCLUSION

Our results show the need for a targeted prevention of overweight. We offer a proposal based on education and behaviour modification in La Reunion Island.

Children’s Preference for Large Portions: Prevalence, Determinants, and Consequences

BACKGROUND

Proliferation of large portions of snack and fast foods parallels dramatic increases in childhood obesity. This study investigates the prevalence, determinants, and consequences of large portions in children's diets.

METHODS

As part of the 2003 Children's Lifestyle and School-performance Study, we surveyed 4,966 children in Nova Scotia regarding their usual portion sizes of french fries, meats, vegetables, and potato chips using three-dimensional graduated food models. We measured heights and weights and assessed dietary intake with the Harvard Youth Adolescent Food Frequency Questionnaire. Diet quality was summarized using the Diet Quality Index International (DQI-I). Parents were surveyed on food habits and socioeconomic background.

STATISTICAL ANALYSIS

We used multilevel regression methods to examine determinants of children's large portion size choice and to evaluate the effect of this selection on energy intake, diet quality, and overweight.

RESULTS

Children reported preference for portions of french fries, meats, and potato chips that are larger and vegetable portions that are smaller than what is recommended. Children from socioeconomically disadvantaged families or who frequently eat while watching television and in fast-food restaurants preferred larger portions of french fries and potato chips. Consequences of consuming large portions of these foods included poor diet quality and increased energy intake. Consuming large portions of vegetables was associated with lower energy intake and better diet quality.

CONCLUSIONS

Successful marketing of large portions of french fries and potato chips may be at the expense of diet quality and appropriate energy intake. Policy regulations and nutrition education emphasizing appropriate portion sizes provide opportunities to prevent overweight and improve future health.

Predictor factors for childhood obesity in a Spanish case-control study

OBJECTIVE

The aim of this study was to identify and characterize factors associated with childhood obesity risk related to lifestyle and perinatal life influences (dietary pattern, physical activity, family history of obesity, breast-feeding, sedentary behavior, and birth weight) in a case-control study design.

METHODS

Cases were 185 obese (body mass index >97th percentile) children and adolescents (6-18 y old) from the Navarra region of Spain and control subjects were matched by sex and age. Anthropometric data were collected, and a personal interview about lifestyle parameters (dietary patterns, physical activity, family history of obesity, breast-feeding and sedentary behaviors) was performed with each participant. Conditional logistic regression was used to identify predictive factors of obesity.

RESULTS

Leisure time physical activity proved to be a protector factor against obesity (odds ratio [OR] 0.94, 95% confidence interval [CI] 0.92-0.96), whereas family history of obesity (OR 4.18, 95% CI 2.20-8.62), watching television (OR 2.02, 95% CI 1.09-3.77), and sugar-sweetened beverage consumption (OR 1.74, 95% CI 1.05-2.89) were associated with a higher obesity risk.

CONCLUSION

Our results suggest that leisure time physical activity, family history of obesity, watching television, and sugar-sweetened beverage consumption are important predictive variables for childhood obesity, whereas other factors including breast-feeding, birth weight, and time spent sleeping did not appear to play an important role in the development of childhood obesity.

Do interventions to limit sedentary behaviours change behaviour and reduce childhood obesity? A critical review of the literature

We sought to determine whether interventions that emphasize decreasing sedentary behaviours in children and adolescents result in behaviour change and weight control. A comprehensive literature search was conducted to identify all comparative studies of interventions to reduce sedentary behaviour among children, alone or in combination with other health messages. Two investigators evaluated articles for eligibility and validity. As methods, settings and interventions differ across studies, results were synthesized narratively. Twelve studies met the inclusion criteria and provided relevant data. Six targeted clinic-based populations that were overweight or at risk of overweight, and six were population-based prevention studies. Approaches varied, but all reduced sedentary behaviour and improved weight indices. An emphasis on decreasing sedentary behaviours is an effective intervention to decrease sedentary behaviours and control weight in children and adolescents.

For comparison: experience with a children’s obesity camp

BACKGROUND

The alarming rise in childhood obesity has resulted in a number of bariatric surgical initiatives. To interpret the outcomes, a comparison with a nonoperative approach is prudent.

METHODS

In 2003, 2004, and 2005, we measured the outcomes produced by an isolated summer camp in North Carolina for 74, 99, and 89 obese children and adolescents with a mean age of 12.7 +/- 2.3, 13.0 +/- 1.9, and 13.2 +/- 1.8 years and initial body mass index (BMI) of 33.1 +/- 5.7, 33.4 +/- 6.4, and 32.9 +/- 7.0 kg/m2, respectively. The camp featured a 1700/d caloric diet, daily aerobic and resistance weight training exercise, nutrition classes, and weekly sessions with a psychologist. The changes in weight, BMI, body shape measurements, and fitness level were assessed. The average length of stay was 4.3, 4.2, and 4.4 weeks, respectively, in 2003, 2004, and 2005.

RESULTS

The BMI, body shape, and weight change measures significantly improved during each of the summers. The campers lost 1.6, 2.0, and 1.8 kg/wk during each of the 3 years. Their waist measurements decreased by 9.1 +/- 5.12 cm, 9.9 +/- 5.6 cm, and 8.1 +/- 5.8 cm. Significant improvements occurred in the timed sprints, .5-mile (0.8-km) run, and vertical jump. Of those campers staying for two summers, 4.4% continued to reduce their BMI despite growth, 56.5% maintained their BMI at less than the initial baseline measurement, and 39.1% increased their BMI to greater than the baseline. The co-morbidities also improved. One camper, aged 15 years, weighing 211 kg, progressed from being able to walk 3 steps to managing the 100-yard (91-m) dash in 42 seconds after losing 35 kg in 8 weeks.

CONCLUSION

Diets, exercise, and behavioral modification are useful approaches in severely obese children that can, in some, produce significant albeit expensive long-term results. Recidivism is a problem. Surgical outcomes must compare favorably with these outcomes.

Extreme obesity: a new medical crisis in the United States

The prevalence of obesity has markedly increased in the past few decades, and this disorder is responsible for more health care expenditures than any other medical condition. The greater the body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters), the greater the risk of comorbidities, including diabetes mellitus, hypertension, obstructive sleep apnea, many cancers, dyslipidemia, cardiovascular disease, and overall mortality. Class III (extreme) obesity, defined as a BMI of 40 kg/m2 or greater, has also increased such that it now affects almost 1 in 20 Americans. The prevalence of extreme obesity is greater among women than among men and greater among blacks than among non-Hispanic whites or Hispanics. The effect of extreme obesity on mortality is greater among young than among older adults, greater among men than among women, and greater among whites than among blacks. The current permissive environment that promotes increased dietary energy intake and decreased energy expenditure through reduced daily physical activity coupled with genetic susceptibility is an important pathogenic factor. The number of bariatric surgical procedures performed annually is relatively small but increasing.

Food advertising targeted at school-age children: a content analysis

OBJECTIVE

To determine whether the contents of food and beverage advertisements are associated with physical activity and athletic ability more often than those for toys and games, and to describe persuasive techniques used in advertising food and beverages to children.

DESIGN

A content analysis of advertisements during 31 hours of school-age children's television programming.

ANALYSIS

Chi-square tests were used to examine differences in depictions of physical activity. Types of persuasive techniques were tabulated and, within each advertisement, categorized as implicit or explicit.

RESULTS

Food and beverage ads depicted children engaged in physical activity and associated the advertised product with athletic ability significantly more than toy and game ads. Food was most often associated with fun and good times (75%), pleasant taste (54.1%), being hip or cool (43.2%), and feelings of happiness (43.2%).

IMPLICATIONS FOR RESEARCH AND PRACTICE

These findings raise concern that greater levels of physical activity and athletic ability in food advertising, in which the product is frequently associated with fun, may promote overconsumption, especially of calorie-dense, nutrient-poor foods. Further research would elucidate whether this concern is warranted. On the other hand, since food advertisements are presumably effective, health educators can use these techniques to formulate messages for nutritious foods. This concept should be tested with well-designed interventions.

Translational research in childhood obesity prevention

This article explores the state of translational research in childhood obesity prevention. Five phases of translational research and emerging findings from basic science that could be useful in the design of obesity prevention programs are described. Few intervention studies have been published, and these are dominated by Phase 3 trials (efficacy), conducted in school settings, with a limited number of studies finding significant effects on Body Mass Index or adiposity. Cost-benefit analyses are lacking. Research is needed to translate basic science findings into novel interventions (Phases 1 and 2) and to translate programs with known behavior change capability into dissemination trials (Phase 5). Translation can be facilitated by enhanced communication between basic science and prevention science researchers, the development of interventions for underused settings, using novel strategies, support by institutions and funding agencies for translation, and the design of interventions with translation in mind.

Overweight and Obesity Status among Adolescents from Mexico and Egypt

BACKGROUND

Obesity is on the rise among adults, adolescents and children worldwide, including populations living in developing countries. This study aimed to describe body mass index of adolescents from Mexico and Egypt and to evaluate non-nutritional correlates from two cohort studies.

METHODS

Questionnaire data and weight and height measurements were collected in two large baseline studies in adolescents between 11 and 19 years old attending public school during the 1998-1999 school year in Mexico (n = 10,537) and the 1997 school year in Egypt (n = 1,502). The authors compared body mass index and correlates stratified by sex and country through multivariate linear regression.

RESULTS

Overall prevalence of overweight and obesity was 19.8 and 7.9%, respectively, among the Mexican adolescents and 12.1 and 6.2%, respectively, among the Egyptian adolescents. Based on U.S. Centers for Disease Control and Prevention (CDC) definition growth charts, for Mexico 18% of boys and 21% of girls were overweight and 11% of boys and 9% of girls were obese. In the Egyptian sample, 7% of boys and 18% of girls were overweight and 6% of boys and 8% of girls were obese. The most consistent correlates of body mass index in the Mexican population were age, years of education, smoking, vitamin intake and participating in sports, whereas the factors correlated among Egyptian adolescents were age and rural residence.

CONCLUSIONS

Obesity and overweight are becoming a problem among Mexican and Egyptian youth. Information about the risk factors associated with excessive weight gain during the adolescent period is a first step towards proposing prevention strategies.

A look at food industry responses to the rising prevalence of overweight

The role of the food industry in the response to the epidemic of obesity is guided by many factors, including the current state of knowledge of the problem. There have been efforts among food and beverage companies to help increase our knowledge about the factors contributing to overweight and to investigate product and marketing changes that may help reduce the risk of weight gain. The value of their future contributions is dependent on corporate resolve, but also on interactive guidance from government and health institutions on the best strategies to take and the best research to support. This is especially clear given the complex nature of the causes of obesity and approaches for treatment.

Pathogenesis of type 2 diabetes mellitus

The pathological sequence for type 2 diabetes is complex and entails many different elements that act in concert to cause that disease. This review proposes a sequence of events and how they interact by a careful analysis of the human and animal model literature. A genetic predisposition must exist, although to date very little is known about specific genetic defects in this disease. Whether the diabetes phenotype will occur depends on many environmental factors that share an ability to stress the glucose homeostasis system, with the current explosion of obesity and sedentary lifestyle being a major cause of the worldwide diabetes epidemic. We also propose that a lowered beta-cell mass either through genetic and/or beta-cell cytotoxic factors predisposes for glucose intolerance. As the blood glucose level rises even a small amount above normal, then acquired defects in the glucose homeostasis system occur--initially to impair the beta cell's glucose responsiveness to meals by impairing the first phase insulin response--and cause the blood glucose level to rise into the range of impaired glucose tolerance (IGT). This rise in blood glucose, now perhaps in concert with the excess fatty acids that are a typical feature of obesity and insulin resistance, cause additional deterioration in beta-cell function along with further insulin resistance, and the blood glucose levels rise to full-blown diabetes. This sequence also provides insight into how to better prevent or treat type 2 diabetes, by studying the molecular basis for the early defects, and developing targeted therapies against them.

Prevalence of and risk factors for childhood overweight and obesity

BACKGROUND

Increases in childhood overweight and obesity have become an important public health problem in industrialized nations. Preventive public health action is required, but more research of risk factors is required before evidence-based initiatives can be developed and targeted effectively. We investigated the association between childhood overweight and obesity and risk factors relating to dietary habits, activities, parents and schools.

METHODS

In 2003 we surveyed grade 5 students and their parents and school principals in Nova Scotia. We measured height and weight and assessed dietary habits (using Harvard's Youth/Adolescent Food Frequency Questionnaire), physical and sedentary activities, and parental and school-based risk factors. We estimated neighbourhood income by averaging, per school, the postal-code level means of household income of residential addresses of children attending that school. We used multilevel logistic regression to evaluate the significance of these risk factors for overweight and obesity.

RESULTS

On the basis of measurements taken of 4298 grade 5 students, we estimated the provincial prevalence of overweight to be 32.9% and of obesity to be 9.9%. Children who bought lunch at school were at increased risk of overweight (fully adjusted odds ratio [OR] 1.39, 95% confidence interval [CI] 1.16-1.67), whereas those who ate supper together with their family 3 or more times a week were at decreased risk (OR 0.68, 95% CI 0.52-0.88). Physical education classes 2 or more times a week at school were associated with a decreased risk of overweight (OR 0.61, 95% CI 0.43-0.87) and obesity (OR 0.54, 95% CI 0.33-0.88). Children in high-income neighbourhoods were half as likely to be obese as their peers living in low-income neighbourhoods (OR 0.50, 95% CI 0.36-0.70).

INTERPRETATION

Parents and schools provide important opportunities for public health initiatives for reducing childhood overweight and obesity. Children and schools in low-income neighbourhoods should receive priority in public health initiatives to reduce future socioeconomic inequalities in health.

Prevention of childhood obesity

Childhood obesity is a complex disease with different genetic, metabolic, environmental and behavioural components that are interrelated and potentially confounding, thus making causal pathways difficult to define. Given the tracking of obesity and the associated risk factors, childhood is an important period for prevention. To date, evidence would support preventative interventions that encourage physical activity and a healthy diet, restrict sedentary activities and offer behavioural support. However, these interventions should involve not only the child but the whole family, school and community. If the current global obesity epidemic is to be halted, further large-scale, well-designed prevention studies are required, particularly within settings outside of the USA, in order to expand the currently limited evidence base upon which clinical recommendations and public health approaches can be formulated. This must be accompanied by enhanced monitoring of paediatric obesity prevalence and continued support from all stakeholders at global, national, regional and local levels.