Comparison of the child and parent forms of the Questionnaire on Eating and Weight Patterns in the assessment of children's eating-disordered behaviors.

OBJECTIVE: The assessment of eating-disordered behaviors in middle childhood is challenging. Frequently, both child and parents are queried about the child's eating behavior. However, no direct comparisons between parent and child reports of child eating disturbance have been published. We compared results from the adolescent and parent versions of the Questionnaire on Eating and Weight Patterns (QEWP-A and QEWP-P, respectively) in a nontreatment sample of overweight and normal weight children. METHOD: The QEWP-A and QEWP-P were administered to 142 overweight (body mass index [BMI] > or = 85th percentile) and 121 normal weight (BMI 15th-84th percentile) children, age 9.7 +/- 1.9 years, recruited from the community. RESULTS: The QEWP-A and QEWP-P showed good agreement for the absence of eating-disordered behavior but were not concordant in terms of the number or type of binge eating, overeating episodes, or compensatory weight control behaviors in the past 6 months. Children categorized by their own reports (QEWP-A) as engaging in no overeating, simple overeating, or binge eating behaviors did not differ significantly in body composition or in eating and general psychopathology. Children categorized according to their parents' reports (QEWP-P) as engaging in binge eating had significantly greater body adiposity, eating-disordered cognitions, body dissatisfaction, and parent-reported problems (all ps <.001) than children engaging in no overeating or simple overeating according to the QEWP-P. DISCUSSION: Child and parent reports of eating behaviors are not concordant regarding the presence of binge eating or compensatory behaviors. Further investigation of the utility of these questionnaires is needed before either can serve as a surrogate for a clinical interview.

The relationship between obesity and serum 1,25-dihydroxy vitamin D concentrations in healthy adults.

Several previous reports of small cohorts have found significantly higher serum 1,25-dihydroxy vitamin D (1,25-vit D) in obese compared with nonobese whites. Based on these reports and on recent in vitro studies of adipocytes which suggest that administration of 1,25-vit D can stimulate lipogenesis and inhibit lipolysis, some investigators have proposed that high 1,25-vit D may play a role in promoting or maintaining adipocyte triglyceride stores in obese adults. To test the hypothesis that obesity is commonly associated with increased 1,25-vit D, we examined the relationships between calciotropic hormones and body adiposity in a large cohort of healthy adults. Serum intact PTH, 25-hydroxy vitamin D, and 1,25-vit D were measured in the postabsorptive state in 302 healthy adults who were Caucasian (n = 190; 71% female), African-American (n = 84; 89% female), and of other race/ethnicity (n = 28; 61% female). Results from the 154 obese subjects [body mass index (BMI) 37.3 +/- 5.8 kg/m(2); range, 30.1-58.2 kg/m(2)] were compared with those from 148 nonobese (BMI 25.6 +/- 2.9 kg/m(2); range, 18.0-29.9 kg/m(2)) age-, race-, and sex-matched participants. Body composition was measured by dual energy x-ray absorptiometry. Serum intact PTH was positively correlated with both BMI (r = 0.42; P < 0.0001) and body fat mass (r = 0.37; P < 0.0001). Serum 25-hydroxy vitamin D was negatively correlated with BMI (r = -0.4; P < 0.0001) and body fat mass (r = -0.41; P < 0.0001). Serum 1,25-vit D was also negatively correlated with BMI (r = -0.26; P < 0.0001) and body fat mass (r = -0.25; P = 0.0001). Serum 1,25-vit D was significantly lower in obese than nonobese subjects (105.7 +/- 41.1 vs. 124.8 +/- 36.7 pmol/liter; P < 0.0001) in both Caucasian and African-American adults. We conclude that, because 1,25-vit D concentrations fall with increasing adiposity, it appears unlikely that elevation in 1,25-vit D is an important hormonal mechanism causing or maintaining obesity in adults.

Which metric of relative weight best captures body fatness in children?

OBJECTIVE: To evaluate the relative merits of BMI (kilograms per meter squared) and age- and gender-adjusted BMI, age- and gender-specific z score of BMI, and age- and gender-specific percentiles of BMI as surrogate measures of body fatness among a sample of youth. RESEARCH METHODS AND PROCEDURES: The sample comprised 596 children and adolescents 5 to 18.7 years old and was 40% male and 55% white. Height and weight were measured by trained research staff. DXA was used to determine body fat mass. BMI, age- and gender-specific percentile of BMI, and age- and gender-specific z scores of BMI were computed, and these metrics were compared with measured body fatness. RESULTS: The BMI values in the sample ranged from 12.9 to 55.0 kg/m(2), with a mean of 24.9 kg/m(2). The Spearman correlations with percentage body fat were similar for all of the BMI metrics (r = 0.82 to 0.88). Linear regression models with age- and gender-specific percentiles of BMI explained significantly less of the variance (65%) than models with log-transformed BMI (81%) or age- and gender-specific z scores of BMI (75% to 79%). z scores were the most accurate at classifying children who were overfat (sensitivity = 0.84, specificity = 0.96 for z score > or = 1). However, using a BMI > or = 85th percentile or a BMI > or = 20 kg/m(2) was also accurate at classifying youth. DISCUSSION: The BMI metrics had similar correlations with body fatness, but age- and gender-specific percentiles of BMI were the least accurate proxy measure of body fatness. However, a BMI z score > or = 1, BMI percentile > or = 85, and BMI> or = 20 kg/m(2) are all useful for identifying children who may be overfat.