Relationship between sex of parent and child on weight loss and maintenance in a family-based obesity treatment program.

OBJECTIVE: To determine if the sex of the participating parent/child pair is a contributing factor in initial weight loss and maintenance within a family-based obesity treatment program. DESIGN: A 2-year family-based obesity treatment program targeting one overweight parent and one overweight child. SUBJECTS: One overweight parent (body mass index (BMI) > or = 25) and child (> or = 85th BMI percentile) from 164 families. MEASUREMENTS: Parameters of body weight, including height, weight, BMI, z-BMI, percent overweight (BOV) at baseline and at 6-, 12- and 24-month follow-up time points. RESULTS: Children within the opposite-sex dyads had greater weight loss (P < 0.01) at 6- and 12-month time points compared with children in the same-sex dyads. Parents within opposite-sex dyads had significantly greater weight loss at 24 months (P < 0.05) compared with those in the same-sex dyads. When individual dyads were examined, the change in child z-BMI after 6 months was greater for the mother-son dyad as compared to the mother-daughter and father-son (P < 0.05). For parent z-BMI, the mother-daughter dyad consistently exhibited the poorest results. At 6- and 12-month time points, parents in the mother-daughter dyad lost significantly less weight than parents in all other dyads (P < 0.05), and at 24 months, parents in the mother-daughter dyad lost less weight than parents in the opposite-sex dyads (P < 0.05). CONCLUSION: These data reveal that child-parent sex interactions can strongly influence the outcome of obesity treatment when both parent and child are the target for weight loss. The reasons that underlie this effect remain to be determined.

Sex differences in obese children and siblings in family-based obesity treatment.

OBJECTIVE: The primary goal was to evaluate sex differences in child weight control programs that targeted increasing physical activity (increase) or the combination of reducing sedentary behavior and increasing physical activity (combined). A second goal was to evaluate the benefits of family-based interventions on nontargeted siblings. RESEARCH METHODS AND PROCEDURES: Sixty-seven families with obese children and 89 siblings were randomized to interventions that targeted increasing physical activity (increase) or the combination of reducing sedentary behavior and increasing physical activity (combined). Targeted participants and nontargeted siblings were followed for 1 year. RESULTS: At 12 months, boys showed significantly better percentages of overweight changes (-15.8%) for the combined treatment than girls (-1.0%), with no significant differences for the increase intervention for boys (-9.3%) or girls (-7.6%). Boys adhered to treatment better than girls (p < 0.01). Adherence and predilection for physical activity were significant predictors of targeted child weight loss at 1 year in multiple regression analysis. Predictors of sibling weight loss included age, number of siblings, targeted child percentage of overweight change, and the interaction of group assignment by same sex of treated sibling. DISCUSSION: Gender may influence response to programs that attempt to decrease sedentary behavior, and generalization of treatment effects to siblings may depend on the intervention and characteristics of the siblings.

How much activity do youth get? A quantitative review of heart-rate measured activity.

OBJECTIVE: Recommendations for adult physical activity have shifted from 20 to 60 minutes of continuous vigorous activity 3 to 5 times a week to accumulation of 30 minutes of moderate to vigorous physical activity most days of the week. Variations of these guidelines also have been suggested for children, based on the idea of accumulating moderate to vigorous physical activity throughout the day, rather than attaining vigorous physical activity in continuous blocks. The goal of this study was to assess accumulated amounts of physical activity at different intensities in children. METHODS: We reviewed 26 studies (n = 1883) in youth aged 3 to 17 years that used heart-rate recording to measure physical activity in children to determine accumulated daily activity. Included were studies that provided time being active for at least 2 heart rate intensities at or above 120 beats/minute. Descriptive characteristics of the study groups were determined, and the influence of age, gender, and hours and days of observation on the slope of activity time as a function of percentage of heart rate reserve (HRR) was determined using hierarchical linear regression. RESULTS: Youth attained 128.0 +/- 45.6, 47.1 +/- 14.9, 29.3 +/- 13.7, and 14.7 +/- 6.0 minutes/day between 20% to 40%, 40% to 50%, 50% to 60%, and greater than 60% HRR, respectively. Age was a significant predictor of the intercept and slope of the physical activity and %HRR relationship. CONCLUSION: Youth of all ages attain >60 minutes/day of low-intensity physical activity and approximately 30 minutes/day of activity at traditional cardiovascular fitness training levels of 50% or more of HRR. Recommendations for youth activity are discussed.

Parental activity as a determinant of activity level and patterns of activity in obese children.

The purposes of this study were to measure the level and pattern of moderate-to-vigorous physical activity (MVPA = > 4.5 METs) and examine predictors of activity in obese children. Fifty-one 8-12-year-old children seeking obesity treatment wore accelerometers for 3 or 4 days. Children averaged 12.2 bouts of MVPA per day that lasted an average of 4.2 min, while parents engaged in 3.9 bouts of MVPA that lasted 4.2 min. Hierarchical regression models showed parent activity improved the prediction of obese children's activity levels and the number of bouts of MVPA but not the duration of MVPA. These results suggest that programs to increase physical activity in obese children should structure the activity in short bouts and attempt to increase parental physical activity.

Changes in eating disorder symptoms with pediatric obesity treatment.

OBJECTIVE: To evaluate the effects of behavioral, family-based treatment on disordered eating and child behavior problems for obese 8- to 12-year-old children. STUDY DESIGN: We examined disordered eating in children and parents using the Kids' Eating Disorder Survey (KEDS) and the Binge Eating Scale, respectively; and psychologic problems in children and their parents using the Child Behavior Checklist and Symptom Checklist-90, respectively, in 47 families who participated in a family-based obesity treatment program. RESULTS: Obese children showed significant decreases (-12.5 +/- 13.5) in percent overweight, internalizing problems (-7.0 +/- 7.3), and total behavior problems (-4.8 +/- 6.6) and increases in behavioral competence (3.7 +/- 5.0) over 2 years of measurement; and their parents showed significant decreases in weight (-5.0 +/- 8.3 kg) and reductions in parental distress (-2.3 +/- 7.6) and in disturbed eating and weight-related cognition (-3.2 +/- 5.3). No significant changes were observed in total KEDS (-0.2 +/- 1.9), weight dissatisfaction (-0.3 +/- 1.7), or purging/restricting (0.2 +/- 0.6) scores. Decreases in total KEDS were related to decreases in total behavior problems and externalizing behavior problems. CONCLUSIONS: These results document improvements in child behavior problems and competence and no change in symptoms of disordered eating in a standardized behavioral weight control program.

Cost-effectiveness of group and mixed family-based treatment for childhood obesity.

OBJECTIVE: Family-based, behavioral treatment has been shown to be an effective intervention for the management of pediatric obesity. The goal of this study was to compare the cost-effectiveness of two protocols for the delivery of family-based behavioral treatment. RESEARCH METHODS AND PROCEDURES: Thirty-one families with obese children were randomized to groups in which families were provided mixed treatment incorporating both group and individualized treatment vs group treatment only. Cost-effectiveness of treatment was defined as the magnitude of reduction in standardized BMI and percentage overweight per dollar spent for recruitment and treatment. Anthropometric data were assessed at baseline, 6 months and 12 months post-randomization. RESULTS: Results for the 24 families with complete data showed the group intervention was significantly more cost-effective than the mixed treatment. This was due to the similarity between the two groups in Z-BMI or percentage overweight change for children and their parents, while the mixed treatment was significantly more expensive to deliver than the group treatment. DISCUSSION: These findings suggest that a family-based, behavioral intervention employing group treatment alone is a more cost-effective approach to treating pediatric obesity than a mixed group plus individual format.

Problem solving in the treatment of childhood obesity.

This study randomized obese children from 67 families to groups that received a 6-month family-based behavioral weight-control program plus parent and child problem solving, child problem solving, or standard treatment with no additional problem solving. The standard group showed larger body mass index (BMI) decreases than the parent + child group through 2 years, with significant differences in the percentage of children who showed large BMI changes. Significant statistical and clinical improvements were observed over time in child behavior problems and parental distress. Parent problem solving increased in the parent + child condition relative to the other conditions, whereas child problem solving increased equally in all conditions. The bulk of evidence suggests that problem solving did not add to treatment effectiveness beyond the standard family-based treatment.

Decreasing sedentary behaviors in treating pediatric obesity.

BACKGROUND: Epidemiological studies have shown television watching to be a risk factor for the development of obesity in children. The effect of reducing television watching and other sedentary behaviors as a component of a comprehensive obesity treatment program has not been thoroughly tested. OBJECTIVE: To compare the influence of targeting decreases in sedentary behavior vs. increases in physical activity in the comprehensive treatment of obesity in 8- to 12-year-old children. DESIGN: Randomized, controlled outcome study. SETTING: Childhood obesity research clinic. DESIGN: Ninety families with obese 8- to 12-year-old children were randomly assigned to groups that were provided a comprehensive family-based behavioral weight control program that included dietary, and behavior change information but differed in whether sedentary or physically active behaviors were targeted and the degree of behavior change required. RESULTS: Results during 2 years showed that targeting either decreased sedentary behaviors or increased physical activity was associated with significant decreases in percent overweight and body fat and improved aerobic fitness. Self-reported activity minutes increased and targeted sedentary time decreased during treatment. Children substituted nontargeted sedentary behaviors for some of their targeted sedentary behaviors. CONCLUSION: These results support reducing sedentary behaviors as an adjunct in the treatment of pediatric obesity.

Asthma and maternal body mass index are related to pediatric body mass index and obesity: results from the Third National Health and Nutrition Examination Survey.

OBJECTIVE: Clinical research has shown an increased prevalence of obesity in children with asthma. This study was designed to assess the relationship between asthma and pediatric body mass index (BMI) in a national database and to examine factors that may modify this relationship. DESIGN: The cross-sectional relationship between asthma and pediatric BMI and obesity (BMI > or = 85th percentile) was studied. Variables that may influence the relationship between asthma and pediatric BMI, such as race/ethnicity and television watching were included in the model for the total sample. A smaller sample of 3,009 white and African American youth were studied in regression models including maternal BMI. STUDY POPULATION: A nationally representative cross-sectional sample of 5154 children and adolescents of 6 to 16 years of age from the Third National Health And Nutrition Examination Survey. RESULTS: In the full sample, asthma and television watching were related to BMI, accounting for 3% of the variance in BMI. When maternal BMI was included in the non-Hispanic sample, television watching, maternal BMI, and the interaction of maternal BMI and asthma were related to youth BMI, accounting for 15% of the variance. The standardized BMI z-score for those youth without asthma and no maternal obesity was 0.06, which increased to 0.33 if the youth had asthma, to 0.70 if the youth did not have asthma but the mother was obese, and to 1.71 if the youth had asthma and the mother was obese. Asthma, television watching, and maternal BMI were independent predictors of youth obesity. CONCLUSIONS: BMI and prevalence of obesity is higher in youth with asthma. Pediatric BMI, but not obesity, is also related to the interaction of asthma and maternal BMI in white and African American youth. Comorbidity of asthma and obesity may complicate treatment of either condition, and prevention of obesity should be encouraged for asthmatic children.

Reinforcing value of physical activity as a determinant of child activity level.

This study examined whether the relative reinforcing value of physical activity (RRVPA) measured in the laboratory predicted physical activity measured in the natural environment in 32 6-11-year-old children. RRVPA correlated with physical activity level (r = .42, p < .05), and contributed to the prediction of physical activity level along with child obesity. RRVPA was related to the number of moderate to vigorous physical activity exercise bouts (r = .35, p < .05), not to the duration of those bouts. These results suggest that RRVPA is a determinant of child physical activity level, and that it may be naturally more reinforcing for children to engage in multiple, short exercise bouts than fewer, more extended bouts.

The relationship between asthma and obesity in urban minority children and adolescents.

OBJECTIVE: To investigate the relationship between asthma and obesity in children and adolescents. DESIGN: Medical record review. SETTING: Urban community health center. PARTICIPANTS: One hundred seventy-one children aged 4 to 16 years, 85 with asthma and 86 nonasthmatic controls. MAIN OUTCOME MEASURES: Diagnosis of asthma, age, and sex-adjusted body mass index (weight in kilograms divided by the square of the height in meters). RESULTS: Seventy-eight percent of the sample was Hispanic, 17% was African American, 2% were white, and 3% were other minorities. There were significantly more children with asthma (30.6%) who were very obese (> or =95th body mass index percentile) compared with controls (11.6%) (P=.004). Children with asthma were also significantly more overweight than controls (mean+/-SD, 22.5%+/-28.3% vs 12.0%+/-19.6% overweight; P=.004). The difference in obesity between children with asthma and controls was significant for both sexes and across the 4.5 to 10.9 years and 11 to 16 years age groups. Asthma severity was not related to obesity. CONCLUSION: Asthma is a risk factor for obesity in children and adolescents.

Habituation of facial muscle responses to repeated food stimuli.

We have shown in a series of studies that the human salivary response habituates to repeated presentation of gustatory cues. Parallel animal research has shown that mouthing and food acceptance also habituate. Facial expressions represent a complex response pattern in animals and humans that may provide an objective measurement of motivation to eat. The current study assessed whether facial muscles (orbicularis oris region, risorius region, and zygomaticus region) that regulate mouthing habituate to repeated presentations of a small amount (3 kcal) of a pleasant tasting food stimulus. Participants were randomly assigned to groups that received ten presentations of the same or changing taste stimuli. Following these trials all subjects were presented a novel dishabituating stimulus followed by the habituating stimulus. Integrated facial electromyography EMG responses over each region were measured for a 50 second period following the taste stimulus. Results showed differential habituation rates across the two groups, with participants in the repeated taste group showing decreases in contrast to the changing taste group who did not decrease. The participants in the repeated taste group showed dishabituation of these responses. These results systematically replicate basic animal research, and extend the number of responses related to eating in humans that habituate to repeated food presentations.

Determinants of physical activity in obese children assessed by accelerometer and self-report.

Previous research has shown that predictors of activity in adults depend upon the method of measurement. This study is designed to assess the predictors of activity in a sample of 59 obese children. Activity was measured using self-reported and TriTrac accelerometer METs. Self-report and TriTrac accelerometer measures were moderately correlated, r = 0.46, with the self-reported activity (2.3 METs) significantly greater than TriTrac (1.6 METs). Hierarchical regression analysis examined the influence of socioeconomic level, body composition, fitness, hedonics of child and adult activity behaviors, and decisional balance on self-reported and accelerometer-measured activity, controlling for child and parent psychopathology. Child and parent psychological symptoms accounted for 8.3% and 3.4% of the variance in accelerometer and self-reported METs, respectively. The model for accelerometer-measured activity showed socioeconomic level and parent self-report of activity accounted for 14.8% of the incremental variance in child activity. The model for self-report of child activity found that child fitness accounted for 23.5% of the incremental variance in child activity. These results suggest that the predictors of activity level are different based upon the method of measurement, consistent with research in adults.