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.

Effect of El Niño and ambient temperature on hospital admissions for diarrhoeal diseases in Peruvian children.

INTRODUCTION: To investigate whether the El Niño phenomenon and ambient temperature had an effect on the epidemiology of childhood diarrhoea, we analysed data on daily number of admissions of children with diarrhoea to the Oral Rehydration Unit of the Instituto de Salud del Niño in Lima, Peru, between January, 1993, and November, 1998. METHODS: We obtained daily data on hospital admissions from the Oral Rehydration Unit, and meteorological data from the Peruvian Weather Service, and used time-series linear regression models to assess the effects of the 1997-98 El Niño event on admissions for diarrhoea. FINDINGS: 57,331 children under 10 years old were admitted to the unit during the study. During the 1997-98 El Niño episode, mean ambient temperature in Lima increased up to 5 degrees C above normal, and the number of daily admissions for diarrhoea increased to 200% of the previous rate. 6225 excess admissions were attributable to El Niño, and these cost US$277,000. During the period before the El Niño episode, admissions for diarrhoea increased by 8% per 1 degree C increase in mean ambient temperature. The effects of El Niño and ambient temperature on the number of admissions for diarrhoea were greatest during the winter months. INTERPRETATION: El Niño had an effect on hospital admissions greater than that explained by the regular seasonal variability in ambient temperature. The excess increase in ambient temperature was the main environmental variable affecting admissions. If our findings are reproducible in other regions, diarrhoeal diseases may increase by millions of cases worldwide with each degree of increase in ambient temperature above normal.

Effects of Cryptosporidium parvum infection in Peruvian children: growth faltering and subsequent catch-up growth.

The authors conducted a 2-year (1989-1991) community-based longitudinal study in a shantytown in Lima, Peru, to examine the effect of Cryptosporidium parvum infection on child growth during the year following the onset of infection. A cohort of children, aged 0-3 months at recruitment, was followed monthly for anthropometrics, weekly for stool samples, and daily for diarrheal status. Data from 185 children in the cohort permitted a comparison of growth in C. parvum-infected and noninfected children. The analyses fitted smooth, flexible curves with a linear random-effects model to estimate growth differences between C. parvum-infected and noninfected children. Children infected with C. parvum experienced growth faltering, both in weight and in height, for several months after the onset of infection, followed by a period of catch-up growth. Younger children took longer to catch up in weight than did older children. Catch-up growth, however, did not occur in children infected between ages 0 and 5 months. These children did not catch up in height, and one year after infection they exhibited an average deficit of 0.95 cm (95% confidence interval (CI) 0.38-1.53) relative to noninfected children of similar age. Stunted children who became infected also did not catch up in either weight or height, and one year after infection they exhibited a height deficit of 1.05 cm (95% CI 0.46-1.66) relative to noninfected, stunted children of similar age. These results indicate that Cryptosporidium parvum has a lasting adverse effect on linear (height) growth, especially when acquired during infancy and when children are stunted before they become infected.

PIP: A 2-year (1989-91) community-based study conducted in a shantytown in Lima, Peru, used regression splines to assess the effect of Cryptosporidium parvum infection on child growth during the year following the onset of infection. The 185 children 0-3 months of age at enrollment who comprised the study cohort underwent daily monitoring of diarrheal status, weekly stool analysis, and monthly anthropometric measurements. 88 children (48%) became infected with C. parvum during the study period. A linear random effects model was used to model differences in temporal growth patterns between C. parvum-infected and noninfected children. Children infected with C. parvum demonstrated growth faltering, both in weight and height, for several months after the onset of infection, followed by a period of catch-up growth. Younger age at infection intensified the effect of C. parvum infection on growth. In children infected between 0 and 5 months of age, catch-up weight gain was complete 6 months later but, 12 months after infection, these children exhibited an average height deficit of 0.95 cm relative to uninfected children the same age. Stunting also increased the magnitude and duration of the effect of C. parvum infection on growth. 12 months after infection onset, stunted children demonstrated a 1.05 cm height deficit relative to their noninfected, nonstunted age counterparts. These findings indicate that cryptosporidiosis has an adverse effect on child growth, especially when infection is acquired during infancy. C. parvum-related intestinal damage and malabsorption are presumed to be the mechanisms associated with growth retardation.

Use of generalized regression tree models to characterize vegetation favoring Anopheles albimanus breeding.

We propose the use of generalized tree models (GTMs) to analyze data from entomological field studies. Generalized tree models can be used to characterize environments with different mosquito breeding capacity. A GTM simultaneously analyzes a set of predictor variables (e.g., vegetation coverage) in relation to a response variable (e.g., counts of Anopheles albimanus larvae), and how it varies with respect to a set of criterion variables (e.g., presence of predators). The algorithm produces a treelike graphical display with its root at the top and 2 branches stemming down from each node. At each node, conditions on the value of predictors partition the observations into subgroups (environments) in which the relation between response and criterion variables is most homogeneous.

Asymptomatic and symptomatic cryptosporidiosis: their acute effect on weight gain in Peruvian children.

This study investigated whether a child's first infection with Cryptosporidium parvum had an acute effect on weight gain. Specifically, the authors compared monthly rates of weight gain between C. parvum-infected and noninfected children. Over a 2-year period (1989-1991), a cohort of Peruvian children aged 0-3 months at recruitment were followed twice weekly for assessment of daily diarrheal status, weekly for C. parvum stool examinations, and monthly for anthropometric measurements. Data on 207 children permitted the authors to examine the effect of C. parvum infection on weight gain. During the 2-year study period, 45% (94/207) of the children became infected with C. parvum for the first time. Weight gain intervals in 57 of the 94 infected children met criteria for analysis. Of these, 63 percent (36/57) were asymptomatic (i.e., had no diarrhea). On average, children with symptomatic cryptosporidiosis gained (i.e., grew) 342 g less (95% confidence interval 167-517) during the first month of infection than did children without diarrhea who were not yet infected. The effect of asymptomatic cryptosporidiosis was less severe: On average, children with asymptomatic infection gained 162 g less (95% confidence interval 27-297) during the first month of infection than did children without diarrhea who were not yet infected. Symptomatic cryptosporidiosis retarded weight gain more than did asymptomatic cryptosporidiosis, but the latter was twice as common. Since asymptomatic cryptosporidiosis is more prevalent, it may have more of an overall adverse effect on child growth in the community than symptomatic cryptosporidiosis.

PIP: During September 1989-November 1991 in Peru, 207 infants, 0-3 months old at enrollment and living in a periurban shanty town in Lima, were followed to determine whether a child's first infection with Cryptosporidium parvum had an adverse effect on weight gain during the first month of infection and whether poor nutritional status was a risk factor for C. parvum. Infection with C. parvum occurred at least once in 45% (97) of the infants. Median age at onset of a first C. parvum infection was 16 months. The growth interval of only 57 (61%) of C. parvum infected children was evaluated. 36 (63%) children were asymptomatic. The remaining 21 infected children had diarrhea. Children with cryptosporidiosis, whether symptomatic or asymptomatic, gained less weight during the first month of infection than children without cryptosporidiosis. Children with symptomatic cryptosporidiosis gained 184 g less weight during the first month of infection than did children with asymptomatic cryptosporidiosis. Children with symptomatic cryptosporidiosis gained 342 g less during the first month of infection than did children who were not infected with C. parvum and did not have diarrhea. Children with asymptomatic cryptosporidiosis gained 162 g less during the first month of infection than did children who were not infected with C. parvum and did not have diarrhea. The adverse effect of C. parvum on weight gain was strongest in children younger than 12 months. Neither wasting nor underweight was a significant risk factor for C. parvum infection. Stunting tended to increase the risk of C. parvum infection but the effect was not statistically significant. These findings show that C. parvum infection has an adverse effect on growth. Asymptomatic cryptosporidiosis is of special concern, since it was more prevalent and thus probably would have more of an overall adverse effect on child growth in the community.

Effect of weight loss by obese children on long-term growth.

OBJECTIVE: To assess height growth over 10 years in children treated for obesity. DESIGN: Longitudinal, prospective follow-up of a series of randomized, controlled weight control trials. SETTING: Specialized pediatric weight control clinic. PARTICIPANTS: One hundred fifty-eight 6- to 12-year-old obese children who were followed up for 10 years after treatment. INTERVENTIONS: Family-based behavioral weight control. MEASUREMENTS/MAIN RESULTS: At entry the height percentiles of the obese children were significantly higher (71.6 percentile) than same-sex parent (52.0 percentile) or midparent (51.5 percentile) height (an estimate of parental contribution to height). After an average growth of 22.7 cm, children were 2.2 cm taller than their same-sex parent and decreased to an average height percentile of 57.8. Multiple regression analysis showed that child sex, age, baseline height and percent overweight, midparent height, and height change of the child from baseline to 5 years accounted for 94% of the variance in growth. Child percent overweight change made no contribution to predicting height change. Comparison between children obese and nonobese at 10 years showed no differences in growth. CONCLUSIONS: Moderate energy restriction with dietary guidance by overweight children did not negatively influence long-term growth.

Behavioral economic analysis of food choice in obese children.

Behavioral economic analysis has shown food choice in normal weight adults is influenced by both liking and constraints on access to food. The present study assessed the contributions of food liking and environmental constraints to choice of moderately liked, low-calorie foods or highly liked high-calorie foods in obese children. Access to the moderately liked food remained on a VR2 schedule, while response requirements for the highly liked food ranged from VR2 to VR32. Subjects chose to work for the higher-rated food at comparisons up to VR2/VR4, showed no preference at VR2/VR8 and their choice shifted to the lower rated food when response requirements for the highly liked food were increased to VR16. These results show that both subjective and environmental factors contribute to children's choice of foods.

Effects of a very-low-calorie diet on long-term glycemic control in obese type 2 diabetic subjects.

We tested the hypothesis that the use of a very-low-calorie diet (VLCD) in combination with behavior modification would promote long-term glycemic control in obese type 2 diabetic subjects. Thirty-six diabetic subjects were randomly assigned to a standard behavior therapy program or to a behavior therapy program that included an 8-week period of VLCD. The behavior therapy group consumed a balanced diet of 4200 to 6300 J/d throughout the 20-week program. The VLCD group consumed a balanced diet of 4200 to 6300 J for weeks 1 to 4, followed by a VLCD (1680 J/d of lean meat, fish, and fowl) for weeks 5 to 12. The VLCD group then gradually reintroduced other foods during weeks 13 to 16 and consumed a balanced diet of 4200 to 6300 J/d for weeks 17 to 20. Thirty-three of the 36 subjects completed the 20-week program and the 1-year follow-up. Use of the VLCD produced greater decreases in fasting glucose at the end of the 20-week program and at 1-year follow-up and greater long-term reductions in HbA1. The VLCD group also had greater weight losses at week 20, but weight losses from pretreatment to 1-year follow-up were similar in the two treatment groups. The improved glycemic control with the VLCD appeared to be due to increased insulin secretion, but further research is needed to confirm this.

Growth in obese children treated for obesity.

This study assesses the growth patterns during a 5-year period in children aged 6 to 12 years treated for obesity using behavioral family-based treatment procedures. Previous studies have suggested a decrease in height velocity after weight reduction, but these results did not consider either the height of the parent or the greater height of obese than nonobese children. Results show that at entry, obese children are taller than their nonobese peers (74th percentile), and that even after 5 years, they remain taller than the norm (65th percentile). Child weight and level of physical maturity accounted for 54% of the variance in predicting baseline height percentile. Entrance height and parental height accounted for 9% of the variance in changes in height percentile, both adjusted for parental height. Weight change did not correlate with growth adjusted for parental height. These results do not suggest that negative effects on height are a long-term side effect of child weight control.

Metabolic effects of nicotine after consumption of a meal in smokers and nonsmokers.

The thermogenic effect of nicotine intake after calorie consumption was investigated to determine if nicotine influences metabolic response to a calorie challenge. Smokers and nonsmokers (10 males in each group), matched for body weight, age, and physical fitness, each participated in four sessions that involved consuming a liquid calorie load (4.77 kcal/kg body wt) or water, followed by nicotine (15 micrograms/kg body wt) or placebo via nasal spray every 20 min for 2 h. Energy expenditure was significantly increased above baseline resting metabolic rate (RMR) over the 2 h by nicotine alone (6.5% of RMR, p less than 0.01). However, the combined effect of nicotine after calorie load (20.1% of RMR, p less than 0.001) was not significantly greater than the effect of calorie load alone (18.4% of RMR, p less than 0.001). Smokers and nonsmokers did not differ in baseline RMR or in response to nicotine or calorie load. These results confirm the thermogenic effect of nicotine but suggest that the effect of nicotine after calorie consumption is less than additive.

Acute effects of nicotine on resting metabolic rate in cigarette smokers.

The acute effects of nicotine on resting metabolic rate (RMR) were examined to identify a mechanism that may help explain the inverse association between smoking and body weight. Multiple administrations of two nicotine doses (moderate [15 micrograms/kg body wt] and low [7.5 micrograms/kg body wt]) and a placebo (0 micrograms) were presented to 18 male smokers via nasal-spray solution on three separate occasions while RMR was assessed by computerized open-circuit indirect calorimetry. Plasma nicotine levels confirmed the reliability of dosing. RMR increases of 6% above base line after both moderate and low doses were significantly greater than the 3% increase after the placebo. Subsequent examination of the effects of smoking a nonnicotine cigarette suggested that the small placebo effect was due to acute metabolic consequences of inhalation. These results confirm that intake of nicotine, isolated from tobacco smoke, significantly increases RMR in humans. However, the results also indicate that non-pharmacological, behavioral aspects of smoking may also contribute to acutely increasing RMR in smokers.

The effects of physical activity as maintenance for smoking cessation.

The effects of physical activity as a maintenance strategy for smoking cessation were evaluated. After a standard smoking cessation program, forty-two women were randomly assigned to one of three groups that received equal number of maintenance meetings: a physical activity program, smoking habit change information and contact control. Abstinence decreased from 83% at the end of treatment to 73% at 3 months, 49% at six months and 34% at 18 months. No differences were shown in cessation across groups. Group differences were shown for subjective levels of tension-anxiety, those who exercised showed increased tension anxiety levels compared to subjects in the no activity groups.

Long-term effects of modest weight loss in type II diabetic patients.

Since most obese patients with type II diabetes are unable to achieve ideal body weight, this study examined whether more modest weight losses would provide a long-term benefit. Type II diabetic patients (N = 114) were treated in a behavioral weight control program and followed up for one year. Weight loss was significantly correlated with improvements in glycosylated hemoglobin values at posttreatment (r = .55) and one year (r = .51). Patients who lost more than 6.9 kg or had more than 5% reduction in body weight had significant improvements in glycosylated hemoglobin values at one year, while patients losing less weight had nonsignificant changes and those gaining weight had significant worsening. Thus, modest weight loss can have a long-term impact on glycemic control. However, the improvement in glycemic control for a given weight loss was greater initially than at one year, suggesting that energy restriction, in addition to weight loss, may contribute to initial improvement. Neither percent overweight nor diabetes treatment affected weight loss.

Effect of diet and controlled exercise on weight loss in obese children.

The effects of adding exercise to diet for weight control in obese children were evaluated by randomizing obese girls to one of two groups: diet and diet plus exercise. During the first 6 weeks of the treatment, children exercised in a supervised three times a week exercise program, in which they walked or ran 3 miles. Significant decreases from baseline weight and in percent overweight were observed for both groups during the year of treatment. Significant decreases in percent overweight were observed at 0 to 2 months and then at 2 to 6 months for the children who were exercising, whereas percent overweight in children in the diet-alone group decreased only from 0 to 2 months. In addition, a significant improvement in fitness was observed only for children in the diet plus exercise group.