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.

Prediction equations for resting energy expenditure in overweight and normal-weight black and white children.

BACKGROUND: Accurate estimation of children's resting energy expenditure (REE) is important for planning dietary therapy. OBJECTIVE: Our objective was to compare the utility of 5 REE prediction equations in a diverse sample of young children. DESIGN: REE was obtained in 502 black and white girls and boys aged 6-11 y by using indirect calorimetry at 4 US sites. Measured REE and REE predicted from the equations were compared. RESULTS: None of the equations provided both accurate and unbiased estimates of REE. Two new sets of sex-specific equations including race as a factor were generated and evaluated. One set used easily measured variables-females: REE = 0.046 x weight - 4.492 x 1/height(2) - 0.151 x race + 5.841; males: REE = 0.037 x weight - 4.67 x 1/height(2) - 0.159 x race + 6.792-and accounted for 72% and 69%, respectively, of REE variance. The other set used body-composition variables-females: REE = 0.101 x fat-free mass + 0.025 x fat mass + 0.293 x height(3) - 0.185 x race + 1.643; males: REE = 0.078 x fat-free mass + 0.026 x fat mass - 2.646 x 1/height(2) - 0.244 x race + 4.8-and accounted for 75% and 71%, respectively, of REE variance. When split by race and adiposity, the small bias generated could be corrected to within 0.25 MJ (60 kcal) of the mean measured value. CONCLUSION: Sex-specific equations must take race into account to predict REE adequately in children.

Comparison of methods to assess change in children's body composition.

BACKGROUND: Little is known about how simpler and more available methods to measure change in body fatness compare with criterion methods such as dual-energy X-ray absorptiometry (DXA) in children. OBJECTIVE: Our objective was to determine the ability of air-displacement plethysmography (ADP) and formulas based on triceps skinfold thickness (TSF) and bioelectrical impedance analysis (BIA) to estimate changes in body fat over time in children. DESIGN: Eighty-six nonoverweight and overweight boys (n = 34) and girls (n = 52) with an average age of 11.0 +/- 2.4 y underwent ADP, TSF measurement, BIA, and DXA to estimate body fatness at baseline and 1 +/- 0.3 y later. Recent equations were used to estimate percentage body fat by TSF measurement (Dezenberg equation) and by BIA (Suprasongsin and Lewy equations). Percentage body fat estimates by ADP, TSF measurement, and BIA were compared with those by DXA. RESULTS: All methods were highly correlated with DXA (P < 0.001). No mean bias for estimates of percentage body fat change was found for ADP (Siri equation) compared with DXA for all subjects examined together, and agreement between body fat estimation by ADP and DXA did not vary with race or sex. Magnitude bias was present for ADP relative to DXA (P < 0.01). Estimates of change in percentage body fat were systematically overestimated by BIA equations (1.37 +/- 6.98%; P < 0.001). TSF accounted for only 13% of the variance in percentage body fat change. CONCLUSION: Compared with DXA, there appears to be no noninvasive and simple method to measure changes in children's percentage body fat accurately and precisely, but ADP performed better than did TSF or BIA. ADP could prove useful for measuring changes in adiposity in children.

Sequence variants of the POMC gene and their associations with body composition in children.

We investigated POMC sequence variants in 242 overweight and nonoverweight African-American and white children and examined the associations between body composition and POMC polymorphisms. Three novel polymorphisms and two previously identified sequence variants were found: A7301G, A7429G, and C8246T were all in untranslated regions. A 9-bp (AGC AGC GGC) duplication/insertion was found between positions 7677 and 7678, and one normal-weight African-American girl had a 45-bp triple duplication/insertion at this location. Compared with whites, African-American children were significantly more likely to have polymorphisms A7301G, A7429G, and the 9-bp insertion. However, there were no significant associations between any of the polymorphisms and body composition. Five African-American subjects who were homozygous for A7429G had a trend (p = 0.08) for a greater BMI-SD score (5.3 +/- 5.3 kg/m(2)) compared with wild-type children (BMI-SD score, 2.4 +/- 3.2 kg/m(2)) or heterozygotes (BMI-SD score, 2.7 +/- 3.7 kg/m(2)). However, there were no differences in BMI-SD score for A7429G when African American subjects were studied separately and both gender and height were taken into account. The contribution of the POMC gene variants we studied to pediatric-onset obesity seems to be limited.

Indices of insulin action, disposal, and secretion derived from fasting samples and clamps in normal glucose-tolerant black and white children.

OBJECTIVE: To validate fasting indices of insulin sensitivity and secretion in a diverse pediatric population against gold standard estimates from euglycemic and hyperglycemic clamps. RESEARCH DESIGN AND METHODS: A total of 31 children (mean BMI 25.1 +/- 4.9 kg/m(2), mean age 8.7 +/- 1.4 years, 15 girls and 16 boys, 12 black and 19 white) underwent euglycemic and hyperglycemic clamps 2-6 weeks apart to derive insulin sensitivity indices (SI (Eug clamp) and SI (Hyper clamp)). Fasting samples were used to derive the homeostasis model assessment of insulin resistance index (HOMA-IR), HOMA of percent beta-cell function (HOMA-B%), quantitative insulin sensitivity check index (QUICKI), insulinogenic index, antilipolytic insulin sensitivity index (ISI-FFA), and C-peptide-to-insulin ratio. RESULTS: The QUICKI correlated best with SI (Eug clamp) (r = 0.69, P < 0.05) and had greater correlations to SI (Eug clamp) than did either SI (Hyper clamp) (r = 0.45, P < 0.05) or the HOMA-IR (r = -0.51, P < 0.05). Both fasting insulin and the insulinogenic index correlated well with first- and steady-phase insulin secretion (r's from 0.79 to 0.86, P < 0.05). HOMA-B% was not as highly correlated (r = 0.69-0.72, P < 0.05). Fasting C-peptide-to-insulin ratio was not significantly correlated with clamp-derived metabolic clearance rate of insulin. ISI-FFA was not correlated with the degree of free fatty acid suppression obtained from the clamps. CONCLUSIONS: The QUICKI, fasting insulin, and the insulinogenic index all closely correlate with corresponding clamp-derived indices of insulin sensitivity and secretion in this diverse pediatric cohort. These results, if replicated in similarly diverse populations, suggest that estimates based on fasting samples can be used to rank order insulin secretion and sensitivity in pediatric cohorts.