Eating disorder behaviours amongst adolescents: investigating classification, persistence and prospective associations with adverse outcomes using latent class models.

Diagnostic criteria for eating disorders (ED) remain largely based on clinical presentations, but do not capture the full range of behaviours in the population. We aimed to derive an empirically based ED behaviour classification using behavioural and body mass index (BMI) indicators at three time-points in adolescence, and to validate classes investigating prospective associations with adverse outcomes. Adolescents from the Avon Longitudinal Study of Parents and Children (ALSPAC) provided data on ED at age 14 (n = 6615), 16 (n = 5888), and 18 years (n = 5100), and had weight and height measured. Psychological and behavioural outcomes were assessed at 15.5/16 and 17.5/18 years. We fit gender- and age-stratified latent class models, and employed logistic regression to investigate associations between classes and later outcomes. One asymptomatic and two symptomatic (largely representing higher and lower frequency ED behaviours) classes were observed at each time-point, although their relative prevalence varied by age and gender. The majority of girls in symptomatic classes remained symptomatic at subsequent assessments. Girls in symptomatic classes had higher odds of subsequent anxiety and depressive disorders, binge drinking, drug use, and deliberate self-harm. Data analyses were underpowered amongst boys. The presence of two symptomatic classes (characterised by different ED behaviour frequency) and their prospective association with adverse outcomes suggest a need to refine diagnostic thresholds based on empirical data. Despite some instability of classes, particularly in mid-adolescence, evidence that half of girls in symptomatic classes remained symptomatic suggests persistence of ED behaviours in adolescence, and highlights a need for early identification to reduce chronicity.

Longitudinal Associations Among Posttraumatic Stress Disorder, Disordered Eating, and Weight Gain in Military Men and Women.

Obesity is a major health problem in the United States and a growing concern among members of the military. Posttraumatic stress disorder (PTSD) has been associated with overweight and obesity and may increase the risk of those conditions among military service members. Disordered eating behaviors have also been associated with PTSD and weight gain. However, eating disorders remain understudied in military samples. We investigated longitudinal associations among PTSD, disordered eating, and weight gain in the Millennium Cohort Study, which includes a nationally representative sample of male (n = 27,741) and female (n = 6,196) service members. PTSD at baseline (time 1; 2001-2003) was associated with disordered eating behaviors at time 2 (2004-2006), as well as weight change from time 2 to time 3 (2007-2008). Structural equation modeling results revealed that the association between PTSD and weight change from time 2 to time 3 was mediated by disordered eating symptoms. The association between PTSD and weight gain resulting from compensatory behaviors (vomiting, laxative use, fasting, overexercise) was significant for white participants only and for men but not women. PTSD was both directly and indirectly (through disordered eating) associated with weight change. These results highlight potentially important demographic differences in these associations and emphasize the need for further investigation of eating disorders in military service members.

Adherence to the Mediterranean dietary pattern and BMI change among US adolescents.

BACKGROUND: Among adults, the Mediterranean dietary pattern (MDP) is inversely related to body mass index (BMI). Data are lacking on adherence to the MDP among youth in the United States and whether the MDP is related to weight change in that group. OBJECTIVE: To assess whether adherence to the MDP was associated with BMI change among adolescents. To examine temporality, we studied the association between baseline and 2-3-year changes in adherence to the MDP with concurrent changes in BMI, as well as subsequent changes in BMI over a 7-year period. METHODS: We prospectively followed 6002 females and 4916 males in the Growing Up Today Study II, aged 8-15 years in 2004, living across United States. Data were collected by questionnaire in 2004, 2006, 2008 and 2011. Dietary intake was assessed by the Youth/Adolescent Questionnaire. The KidMed Index was derived to measure the adherence to the MDP. We used generalized estimating equations with repeated measures within subjects to assess the association between MDP and BMI change. RESULTS: A two-point increment in the KidMed Index was independently associated with a lower gain in BMI (-0.04 kg m(-2); P=0.001). A greater increase in adherence to the KidMed Index was independently related to a lower gain in BMI in both the concurrent (P-for-trend<0.001) and the subsequent period (P-for-trend=0.002). CONCLUSIONS: Adherence to MDP was inversely associated with change in BMI among adolescents. Two-year improvement in adherence to MDP was independently associated with less steep gain in the BMI in both the concurrent and the subsequent period.

Is grand-parental smoking associated with adolescent obesity? A three-generational study.

BACKGROUND/OBJECTIVES: Data from previous studies consistently suggest that maternal smoking is positively associated with obesity later in life. Whether this association persists across generations is unknown. We examined whether grand-parental smoking was positively associated with overweight status in adolescence. SUBJECT/METHODS: Participants were grandmother-mother-child triads in the Nurses' Health Study II (NHS II), the Nurses Mothers' Cohort Study and the Growing up Today Study (GUTS). Grandmothers provided information on their and their partner's smoking during pregnancy with the child's mother. Information on child's weight and height at ages 12 (N=3094) and 17 (N=3433) was obtained from annual or biennial GUTS questionnaires. We used logistic regression to estimate the odds ratios (ORs) of being overweight or obese, relative to normal weight. RESULTS: Grand-maternal smoking during pregnancy was not associated with overweight status in adolescence. After adjusting for covariates, the OR of being overweight or obese relative to normal weight at age 12 years in girls whose grandmothers smoked 15+ cigarettes daily during pregnancy was 1.21 (95% confidence interval (CI) 0.74-1.98; P(trend)=0.31) and 1.07 (0.65-1.77; P(trend)=0.41) in boys. Grand-paternal smoking during pregnancy was associated with being overweight or obese at age 12 in girls only, but not at age 17 for either sex: the OR for being overweight or obese at age 12 was 1.38 (95% CI 1.01-1.89; P(trend)=0.03) in girls and 1.31 (95% CI 0.97-1.76; P(trend)=0.07) in boys. Among children of non-smoking mothers, the OR for granddaughter obesity for grand-paternal smoking was attenuated and no longer significant (OR 1.28 (95% CI 0.87-1.89; P(trend)=0.18)). CONCLUSIONS: Our findings suggest that the association between maternal smoking and offspring obesity may not persist beyond the first generation. However, grand-paternal smoking may affect the overweight status of the granddaughter, likely through the association between grand-paternal smoking and maternal smoking.

Longitudinal study of maternal body mass index, gestational weight gain, and offspring asthma.

BACKGROUND: Sparse data are available on the relationship between prenatal exposures and asthma during later childhood. In a longitudinal study of adolescents and their mothers, we examined the association of (i) maternal prepregnancy body mass index (BMI) and (ii) gestational weight gain (GWG), with incidence of allergic and nonallergic asthma in offspring. METHODS: Analyses were conducted using data from 12 963 children aged 9-14 years at enrolment in the Growing Up Today Study, and their mothers, who are participants in the Nurses' Health Study II. Physician-diagnosed asthma and allergies were assessed by questionnaires sent regularly to participants and their mothers. Logistic regression was used to evaluate associations of maternal BMI and GWG with offspring asthma, overall and by subtype. RESULTS: Physician-diagnosed asthma during childhood or adolescence was reported by 2694 children (21%). Maternal prepregnancy overweight (OR: 1.19, 95% CI: 1.03-1.38) and obesity (1.34, 1.08-1.68) were associated with offspring asthma. In asthma subtype analyses, the association was seen only for asthma onset before age 12 years. Moreover, the association of maternal obesity with nonallergic asthma was observed in boys (2.39, 1.40-4.09) and not in girls (0.96, 0.50-1.85; Pinteraction = 0.03); the opposite pattern was suggested for allergic asthma. With regard to GWG, an association was suggested between gains of <15 lb and higher risk of offspring asthma (1.28, 0.98-1.66), without clear allergy- or sex-related patterns. CONCLUSION: The relation of several prenatal factors to risk of childhood asthma supports the early origins hypothesis for asthma. The observed allergy- and sex-specific patterns suggest multiple etiologic pathways.

Adolescent eating disorder behaviours and cognitions: gender-specific effects of child, maternal and family risk factors.

BACKGROUND: Eating disorder behaviours begin in adolescence. Few longitudinal studies have investigated childhood risk and protective FACTORS. AIMS: To investigate the prevalence of eating disorder behaviours and cognitions and associated childhood psychological, physical and parental risk factors among a cohort of 14-year-old children. METHOD: Data were collected from 6140 boys and girls aged 14 years. Gender-stratified models were used to estimate prospective associations between childhood body dissatisfaction, body mass index (BMI), self-esteem, maternal eating disorder and family economic disadvantage on adolescent eating disorder behaviours and cognitions. RESULTS: Childhood body dissatisfaction strongly predicted eating disorder cognitions in girls, but only in interaction with BMI in boys. Higher self-esteem had a protective effect, particularly in boys. Maternal eating disorder predicted body dissatisfaction and weight/shape concern in adolescent girls and dieting in boys. CONCLUSIONS: Risk factors for eating disorder behaviours and cognitions vary according to gender. Prevention strategies should be gender-specific and target modifiable predictors in childhood and early adolescence.

Childhood hyperactivity/inattention and eating disturbances predict binge eating in adolescence.

BACKGROUND: Identifying childhood predictors of binge eating and understanding risk mechanisms could help improve prevention and detection efforts. The aim of this study was to examine whether features of attention-deficit/hyperactivity disorder (ADHD), as well as childhood eating disturbances, predicted binge eating later in adolescence. METHOD: We studied specific risk factors for the development of binge eating during mid-adolescence among 7120 males and females from the Avon Longitudinal Study of Parents and Children (ALSPAC), a cohort study of children in the UK, using data from multiple informants to develop structural equation models. Repeated assessment of eating disturbances during childhood (mid-childhood overeating, late-childhood overeating and early-adolescent strong desire for food), as well as teacher- and parent-reported hyperactivity/inattention during mid- and late childhood, were considered as possible predictors of mid-adolescent binge eating. RESULTS: Prevalence of binge eating during mid-adolescence in our sample was 11.6%. The final model of predictors of binge eating during mid-adolescence included direct effects of late-childhood overeating [standardized estimate 0.145, 95% confidence interval (CI) 0.038­0.259, p = 0.009] and early-adolescent strong desire for food (standardized estimate 0.088, 95% CI −0.002 to 0.169, p = 0.05). Hyperactivity/inattention during late childhood indirectly predicted binge eating during mid-adolescence (standardized estimate 0.085, 95% CI 0.007­0.128, p = 0.03) via late-childhood overeating and early-adolescent strong desire for food. CONCLUSIONS: Our findings indicate that early ADHD symptoms, in addition to an overeating phenotype, contribute to risk for adolescent binge eating. These findings lend support to the potential role of hyperactivity/inattention in the development of overeating and binge eating.

Body satisfaction, weight gain and binge eating among overweight adolescent girls.

OBJECTIVE: To examine if body satisfaction is associated with body mass index (BMI) change and whether it protects against the development of frequent binge eating among overweight and obese adolescent girls. METHODS: We used prospective data from nine waves of an ongoing cohort study of adolescents, the Growing Up Today Study. At enrollment in 1996, participants were 9-14 years old. Questionnaires were mailed to participants annually until 2001, then biennially through 2007. Girls who were overweight or obese in 1996 were included in the analysis (n = 1559). Our outcomes were annual change in BMI and incident frequent binge eating, defined as binge eating at least weekly and no use of compensatory behaviors. RESULTS: At baseline, 57.2% of the overweight and obese girls were at least somewhat satisfied with their bodies. During 11 years of follow-up, 9.5% (95% confidence interval (CI) (7.8, 10.8)) of the girls started to binge eat frequently. Controlling for BMI and other confounders, overweight and obese girls who reported being at least somewhat satisfied with their bodies made smaller BMI gains (ß = -0.10 kg m(-2), 95% CI (-0.19, -0.02)) and had 61% lower odds of starting to binge eat frequently (odds ratio (OR) = 0.39, 95% CI (0.24, 0.64)) than their less satisfied peers. Compared with girls who were the least satisfied with their bodies, girls who were the most satisfied had 85% lower odds of starting to binge eat frequently (OR = 0.15, 95% CI (0.06, 0.37)). The association between body satisfaction and starting to binge eat frequently was stronger for younger adolescents than older adolescents. CONCLUSIONS: Whereas body dissatisfaction is common among overweight and obese girls, body satisfaction may protect against excessive weight gain and binge eating. Prevention of body dissatisfaction must begin early and should be considered as a component of both obesity and eating disorder prevention programs.

Physical activity patterns and prevention of weight gain in premenopausal women.

BACKGROUND: Studies of the association between physical activity (PA) and weight maintenance have been inconsistent. METHODS: We prospectively examined the association between PA patterns and prevention of weight gain among 46 754 healthy premenopausal women, aged 25-43 years in 1989. Participants reported their PA and weight in 1989 and 1997. The primary outcome was gaining >5% of baseline weight by 1997 (62% of the population). RESULTS: Compared with women who maintained <30 min d(-1) of total discretionary activity over 8 years, women were less likely to gain weight if they sustained 30+ min d(-1) (odds ratio (OR)=0.68, 95% confidence interval (CI) 0.64-0.73) or increased to 30+ min d(-1) in 1997 (OR=0.64, 95%CI=0.60-0.68). Among women whose only reported activity was walking, risk of gaining weight was lower in those who sustained 30+ min d(-1) over 8 years (OR=0.66, 95%CI=0.49-0.91), and brisk walking pace independently predicted less weight gain. For a 30 min d(-1) increase between 1989 and 1997, jogging/running was associated with less weight gain than brisk walking or other activities. Greater duration of PA was associated with progressively less weight gain, but even an 11-20 min d(-1) increase was beneficial; the benefits appeared stronger among those who were initially overweight. Sedentary behavior independently predicted weight gain. CONCLUSIONS: Sustained PA for at least 30 min d(-1), particularly if more intense, is associated with a reduction in long-term weight gain, and greater duration is associated with less weight gain. Sedentary women of any baseline weight who increase their PA will benefit, but overweight women appear to benefit the most.

Body mass index, new modes of TV viewing and active video games.

BACKGROUND: Recent technologies have changed screen time. TV can be viewed anywhere, anytime. Content can be collected via digital recorders and online streaming and viewed on smartphones. Video games are no longer strictly sedentary. OBJECTIVES: We sought to assess the unknown relations between new modes of TV viewing - recorded, online, downloaded and on hand-held devices - and active video games with body mass index (BMI). METHODS: Cross-sectional analysis of the 2011 wave of the Growing Up Today Study 2 cohort. We used gender-specific generalized estimating equations to examine screen time and BMI among 3071 women and 2050 men aged 16-24 years. RESULTS: Among women, each hour/day of online TV (0.47; confidence interval [CI]: 0.12, 0.82) and total non-broadcast TV (0.37; CI: 0.14, 0.61) was associated with higher BMI, as was watching ≥ 1/2 h week-1 of TV on hand-held devices (1.04; CI: 0.32-1.77). Active video games were associated with BMI among women, but not after restricting to those not trying to lose/maintain weight. Broadcast TV was associated with higher BMI (kg m-2 ) among women and men (P < 0.05). CONCLUSIONS: Among women, online TV, TV viewed on hand-held devices and the sum of non-broadcast TV time were associated with higher BMI. Broadcast TV was also associated with BMI in women and men.

Impact of overweight on the risk of developing common chronic diseases during a 10-year period.

BACKGROUND: Overweight adults are at an increased risk of developing numerous chronic diseases. METHODS: Ten-year follow-up (1986-1996) of middle-aged women in the Nurses' Health Study and men in the Health Professionals Follow-up Study to assess the health risks associated with overweight. RESULTS: The risk of developing diabetes, gallstones, hypertension, heart disease, and stroke increased with severity of overweight among both women and men. Compared with their same-sex peers with a body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters) between 18.5 and 24.9, those with BMI of 35.0 or more were approximately 20 times more likely to develop diabetes (relative risk [RR], 17.0; 95% confidence interval [CI], 14.2-20.5 for women; RR, 23.4; 95% CI, 19.4-33.2 for men). Women who were overweight but not obese (ie, BMI between 25.0 and 29.9) were also significantly more likely than their leaner peers to develop gallstones (RR, 1.9), hypertension (RR, 1.7), high cholesterol level (RR, 1.1), and heart disease (RR, 1.4). The results were similar in men. CONCLUSIONS: During 10 years of follow-up, the incidence of diabetes, gallstones, hypertension, heart disease, colon cancer, and stroke (men only) increased with degree of overweight in both men and women. Adults who were overweight but not obese (ie, 25.0 < or = BMI < or = 29.9) were at significantly increased risk of developing numerous health conditions. Moreover, the dose-response relationship between BMI and the risk of developing chronic diseases was evident even among adults in the upper half of the healthy weight range (ie, BMI of 22.0-24.9), suggesting that adults should try to maintain a BMI between 18.5 and 21.9 to minimize their risk of disease.

The relation of smoking, age, relative weight, and dietary intake to serum adrenal steroids, sex hormones, and sex hormone-binding globulin in middle-aged men.

The relationships of cigarette smoking, age, relative weight, and dietary intake to serum dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), androstenedione, cortisol, 3-alpha-androstanediol, 3-alpha-androstanediol-glucuronide, testosterone, albumin-bound testosterone, free testosterone, dihydrotestosterone (DHT), and sex hormone-binding globulin (SHBG) were examined cross-sectionally in 1241 randomly sampled middle-aged U.S. men. Compared with nonsmokers and independent of relative weight (body mass index) and age, cigarette smokers had increased serum levels of DHEA (18% higher, P = 0.0002), DHEAS (13% higher, P = 0.0007), cortisol (5% higher, P = 0.01), androstenedione (33% higher, P = 0.0001), testosterone (9% higher, P = 0.009), DHT (14% higher, P = 0.004), and SHBG (8% higher, P = 0.004). Androstenedione, total plasma testosterone, albumin-bound testosterone, DHT, and SHBG decreased with increasing relative weight. Age was positively associated with serum SHBG and negatively associated with albumin-bound testosterone, DHEA, and DHEAS. An association was found between alcohol intake and DHEA (r = 0.15; P = 0.0001), cortisol (r = 0.10; P = 0.0007), and 3-alpha-androstanediol-glucuronide (r = 0.08; P = 0.0004). Cortisol was the only hormone that was associated with carbohydrate intake (r = -0.09; P = 0.002). The only hormones associated with dietary lipids were DHT (for vegetable fat, r = 0.07; P = 0.02), cortisol (for total fat, r = 0.08; P = 0.007), and SHBG (for animal fat, r = -0.06; P = 0.05). In addition, SHBG was positively associated with dietary (r = 0.07; P = 0.008) and crude (r = 0.08; P = 0.007) fiber. These data suggest that serum adrenal steroid and sex hormone concentrations in middle-aged men are more influenced by cigarette smoking, age, and obesity than by dietary intake; however, serum adrenal steroids were influenced by alcohol intake.

Weight concerns, weight control behaviors, and smoking initiation.

OBJECTIVE: To examine the cross-sectional relationships between weight concerns, weight control behaviors, and initiation of tobacco use among youths. STUDY DESIGN: Smoking status, weight concerns, and weight control behaviors were assessed in a cross-sectional sample of 16 862 children, 9 to 14 years of age, in 1996. Logistic regression was used to examine the relationship between weight concerns, weight control behaviors, and early stages of smoking initiation (precontemplation, contemplation, and experimentation). All analyses were adjusted for age, body mass index, and known predictors of initiation. RESULTS: Approximately 9% of participants had experimented with cigarettes, and 6% were contemplating cigarette smoking. Contemplation of tobacco use was associated with misperception of being overweight (boys: odds ratio [OR], 1.65; 95% confidence interval [CI], 1.10-2.48), unhappiness with appearance (girls: OR, 2.05; 95% CI, 1.48-2.84; boys: OR, 1.60; 95% CI, 1.05-2. 42), and a tendency to change eating patterns around peers (girls: OR, 2.87; 95% CI, 2.28-3.62; boys: OR, 1.83; 95% CI, 1.25-2.66). Experimentation with cigarettes was associated with daily exercise to control weight among boys (OR, 1.92; 95% CI, 1.07-3.43) and with monthly purging (OR, 2.54; 95% CI, 1.27-5.07) and daily dieting among girls (OR, 1.79; 95% CI, 1.09-2.96). CONCLUSIONS: Our findings suggest that, among both girls and boys, contemplation of smoking is positively related to weight concerns. Experimentation seems to be positively related to weight control behaviors. It is important for both pediatricians and comprehensive school health programs to address healthy methods of weight maintenance and to dispel the notion of tobacco use as a method of weight control.

The effect of social desirability trait on self-reported dietary measures among multi-ethnic female health center employees.

PURPOSE: To evaluate the effect of social desirability trait, the tendency to respond in a manner consistent with societal expectations, on self-reported fruit, vegetable, and macronutrient intake. METHODS: A 61-item food frequency questionnaire (FFQ), 7-item fruit and vegetable screener, and a single question on combined fruit and vegetable intake were completed by 132 female employees at five health centers in eastern Massachusetts. Intake of fruit and vegetables derived from all three methods and macronutrients from the FFQ were fit as dependent variables in multiple linear regression models (overall and by race/ethnicity and education); independent variables included 3-day mean intakes derived from 24-hour recalls (24HR) and score on the 33-point Marlowe-Crowne Social Desirability scale (the regression coefficient for which reflects its effect on estimates of dietary intake based on the comparison method relative to 24HR). RESULTS: Results are based on the 93 women with complete data and FFQ-derived caloric intake between 450 and 4500 kcal/day. In women with college education, FFQ-derived estimates of total caloric were associated with under-reporting by social desirability trait (e.g., the regression coefficient for total caloric intake was -23.6 kcal/day/point in that group versus 36.1 kcal/day/point in women with education less than college) (difference = 59.7 kcal/day/point, 95% confidence interval (CI) = 13.2, 106.2). Except for the single question on which women with college education tended to under-report (difference =.103 servings/day/point, 95% CI = 0.003, 0.203), there was no association of social desirability trait with self-reported fruit and vegetable intake. CONCLUSIONS: The effect of social desirability trait on FFQ reports of macronutrient intake appeared to differ by education, but not by ethnicity or race. The results of this study may have important implications for epidemiologic studies of diet and health in women.

Distinguishing recovery from remission in a cohort of bulimic women: how should asymptomatic periods be described?

BACKGROUND: Empirical definitions of remission and recovery from eating disorders are needed to understand outcome data and compare results across studies. METHOD: 106 treatment-seeking women with bulimia nervosa, who had abstained from binging and purging for at least 4 weeks, were followed prospectively. Relapse was defined as at least 4 consecutive weeks of either binging and purging weekly or binging two or more times per week, regardless of purging. Recovery was differentiated from remission based on the probability of relapse. The minimum number of weeks after which the risk of relapse leveled off was used as the cut-off to distinguish between the two outcomes. Kaplan-Meier methods were used to estimate the weekly probability of relapse. RESULTS: When defining remission as at least 4 weeks of being asymptomatic, a quarter of the women relapsed within 11 weeks. By 37 weeks, only 49% of the women remained asymptomatic (95% CI, 41-61). The probability of relapse was substantial for approximately a year after a woman ceased to binge and purge. CONCLUSION: Bulimia nervosa is an episodic disorder. As a conservative approach, periods of being asymptomatic that last less than 1 year should be labeled as remissions, not recoveries.

Relation of peer and media influences to the development of purging behaviors among preadolescent and adolescent girls.

OBJECTIVE: To assess prospectively the relation of peer and media influences on the risk of development of purging behaviors. DESIGN: Prospective cohort study. SETTING: One year follow-up of 6982 girls aged 9 to 14 years in 1996 who completed questionnaires in 1996 and 1997 and reported in 1996 that they did not use vomiting or laxatives to control weight. MAIN OUTCOME MEASURE: Self-report of using vomiting or laxatives at least monthly to control weight. RESULTS: During 1 year of follow-up, 74 girls began using vomiting or laxatives at least monthly to control weight. Tanner stage of pubic hair development was predictive of beginning to purge (odds ratio [OR] = 1.8; 95% confidence interval [CI], 1.3-2.4). Independent of age and Tanner stage of pubic hair development, importance of thinness to peers (OR = 2.3; 95% CI, 1.8-3.0) and trying to look like females on television, in movies, or in magazines (OR= 1.9; 95% CI, 1.6-2.3) were predictive of beginning to purge at least monthly. Regardless of the covariates included in the logistic regression model, the risk of beginning to purge increased approximately 30% to 40% per 1-category increase in frequency of trying to look like females on television, in movies, or in magazines. CONCLUSIONS: Both peers and popular culture, independent of each other, exert influence on girls' weight control beliefs and behaviors. Therefore, to make eating disorder prevention programs more effective, efforts should be made to persuade the television, movie, and magazine industries to employ more models and actresses whose weight could be described as healthy, not underweight.

Impact of a school-based interdisciplinary intervention on diet and physical activity among urban primary school children: eat well and keep moving.

OBJECTIVE: To evaluate the impact of a school-based interdisciplinary health behavior intervention on diet and physical activity among children in grades 4 and 5. DESIGN: A quasiexperimental field trial with 6 intervention and 8 matched control schools. Outcomes were assessed longitudinally using preintervention (fall 1995) and follow-up (spring 1997) student survey food frequency and activity measures and follow-up 24-hour recall measures of diet and activity. Change was also assessed using yearly repeated cross-sectional surveys of all grade 5 students from 1995 through 1997. PARTICIPANTS: Longitudinal data were collected from 479 students initially in grade 4 in Baltimore, Md, public schools; 91% were African American. Repeated 24-hour recall measures in 1997 were collected for a random subsample of 336 students. Cross-sectional survey data were collected from all grade 5 students in 1995,1996, and 1997 (n = 2103). INTERVENTION: The Eat Well and Keep Moving Program was taught by classroom teachers over 2 years in math, science, language arts, and social studies classes. Materials provided links to school food services and families and provided training and wellness programs for teachers and other staff members. Intervention materials focused on decreasing consumption of foods high in total and saturated fat and increasing fruit and vegetable intake, as well as reducing television viewing and increasing physical activity. MAIN OUTCOME MEASURES: Dietary intake and physical activity measured via repeated 24-hour recall were primary end points, with additional food frequency and activity measures. RESULTS: The 24-hour recall measures indicated that, after controlling for baseline covariates, the percentages of total energy from fat and saturated fat were reduced among students in intervention compared with control schools (-1.4%; 95% confidence interval [CI], -2.8 to -0.04; P = .04 and -0.60%; 95% CI, -1.2 to -0.01; P = .05). There was an increase in fruit and vegetable intake (0.36 servings/4184 kJ; 95% CI, 0.10-0.62; P=.01), in vitamin C intake (8.8 mg/4184 kJ; 95% CI, 2.0-16; P=.01), and in fiber consumption (0.7 g/4184 kJ; 95% CI, 0.0-1.4; P=.05). Television viewing was marginally reduced (-0.55 h/d; 95% CI, -1.04 to 0.04; P=.06). Analysis of longitudinal and repeated cross-sectional food frequency data indicated similar significant decreases in the percentages of total energy from fat and saturated fat. CONCLUSION: Evaluation of the Eat Well and Keep Moving Program indicates effectiveness in improving dietary intake of students and reducing television viewing.

The relationship of caloric intake to frequency of dieting among preadolescent and adolescent girls.

OBJECTIVE: To assess the relationships of concern with weight and shape, frequency of dieting, body mass index (weight/height2), and energy intake among 431 preadolescent and adolescent girls from a working-class New England suburb. METHOD: A cross-sectional study design used self-report measures of concern with weight, frequency of dieting, and average dietary intake. RESULTS: Approximately 30% of the girls in each age stratum were above the national age-standardized 85th percentile for body mass index (BMI). Body mass index was positively associated with concern about weight and shape (r = 0.46, p = 0.0001) and frequency of dieting (r = 0.49, p = 0.0001). Extreme concern with weight and shape was most common among the obese preadolescent and adolescent girls; however, dissatisfaction was also present among the underweight females. Fifty percent of the girls who were below the national age-standardized 15th percentile for BMI reported their ideal weight is less than their current weight, implying that among young women thinness is not adequate protection against dissatisfaction with weight and shape. Frequency of dieting was positively associated with concern about weight and shape (r = 0.53, p = 0.001) but not physical activity (r = -0.04, p = 0.36). Overall, we did not find strong evidence that dieters were eating less than their nondieting peers. Only among high school students was there a significant negative association between frequency of dieting and energy intake (r = -0.20, p = 0.01), suggesting that "dieting" may have a different meaning to preadolescents and adults. CONCLUSIONS: These findings indicate that self-reported frequent dieting in preadolescent and young adolescent girls is more indicative of extreme concern with weight than of decreased energy intake. Furthermore, extreme concern with weight and shape is most common among the obese preadolescent and adolescent girls.

Subtyping eating disorders: is it justified?

OBJECTIVE: DSM-IV subtypes anorexia nervosa by the presence or absence of bulimic symptoms. Assessing whether bulimic symptoms are related to the probability of recovery can provide justification for subtyping of anorexia. METHOD: Two hundred twenty-five treatment-seeking women with anorexia and/or bulimia nervosa were interviewed every 3 months for up to 4 years. Survival methods were used for analyses. RESULTS: Less than half of the entire cohort recovered; however, the great majority of the women became less symptomatic over time. Contrary to findings from previous studies, bulimic anorexics had a higher rate of recovery than restricting anorexics. CONCLUSION: Differences in course provide some support for the subtyping of anorexia nervosa. Additional prospective studies are needed before subtyping can be warranted.

Overweight, weight concerns, and bulimic behaviors among girls and boys.

OBJECTIVE: To assess the prevalence rates and correlates of overweight, concern with weight, and bulimic behaviors. METHOD: A survey was completed by a population-based sample of 16,114 boys and girls aged 9 to 14 years. RESULTS: Although fewer girls (19%) than boys (26%) were overweight, more girls (25% versus 22%) perceived themselves as overweight (p < .001). The proportion of girls reporting trying to lose weight increased with age (p < .001). The prevalence of binge eating at least monthly increased with age among the girls, but remained stable among the boys. The prevalence of purging was low (< or = 1%) and comparable between genders until age 13. Among the 13- and 14-year-olds, girls were significantly more likely than boys to report using laxatives or vomiting to control weight (p < or = .001). Purging was independently positively associated with stage of pubertal development (girls: odds ratio [OR] = 2.1, 95% confidence interval [CI] 1.6-2.7; boys: OR = 1.5, 95% CI 1.0-2.2) and overweight (girls: OR = 1.9, 95% CI 1.2-3.0; boys: OR = 2.7, 95% CI 1.4-5.1). CONCLUSIONS: Misperception of being overweight and concern with weight were common. Purging was a very rare behavior, but increased with pubertal development. Among the girls, the prevalence increased sharply around the onset of adolescence.