Sarah T. Henes

Camp-Based Immersion Treatment for Obese, Low Socioeconomic Status, Multi-Ethnic Adolescents

BACKGROUND Immersion treatment (IT) provided in a camp setting has been shown to promote short-term improvements in weight and health status in obese adolescents. However, evidence of ITs long-term efficacy and efficacy for multi-ethnic and lower socioeconomic status (SES) adolescents is limited. METHODS This was a cohort study with a pre/post design and longitudinal follow-up. The intervention was a 19-day camp-based IT program comprising (1) a nutrition curriculum and ad-lib access to a nutritious diet, (2) several hours of physical activity daily, (3) group therapy, and (4) cognitive-behavioral therapy (CBT). This analysis included 52 low-SES adolescents that participated in 2009 and 2010. A subgroup of 33 campers and their families was offered follow-up monthly for 10 months. Primary outcome measures were change in weight-related parameters immediately postcamp and after 10 months of follow-up. RESULTS Campers had significant short-term improvements in mean waist circumference (mean [M], 2.6; standard deviation [SD], 3.2 cm), weight (M, 2.6; SD, 1.9 kg), BMI (M, 1.1; SD, 0.9 kg/m2), BMI z-score (M, 0.06; SD, 0.07), and percent overweight (M, 6.1; SD, 4.7). Campers offered follow-up had a modest increase in mean percent overweight (M, 2.0; SD, 8.4) during 10 months of follow-up. However, 33% experienced continuing decline in percent overweight during follow-up, and long-term follow-up was associated with significant overall (precamp vs. end of follow-up) improvements in percent overweight (M, 4.9; SD, 7.2). CONCLUSIONS Camp-based IT with CBT is a promising intervention for improving short- and long-term weight status of low-SES adolescents. Additional research is needed to increase long-term efficacy.

Insulin Resistance Status: Predicting Weight Response in Overweight Children

OBJECTIVE To assess the relationship between insulin resistance and body mass index (BMI) z score associated with dietary modification that focuses on limiting sweetened beverage consumption in overweight children. DESIGN A retrospective cohort study conducted between July 1, 2004, and April 28, 2006. SETTING Community-based primary care practices treating children. PATIENTS Forty-five children (aged < or =18 years) at or above the 95th percentile of BMI for age and sex. Intervention Children and parents were instructed by a dietitian regarding caloric reduction and modification of sweetened beverage intake. MAIN OUTCOME MEASURES Insulin resistance at baseline was calculated from fasting insulin and glucose levels (ie, homeostatic model assessment [HOMA]) and change in BMI z score from baseline to 12-week follow-up. RESULTS Change in BMI z score in response to a decrease in sweetened beverages correlated (Pearson product moment correlation coefficient = 0.42; P < .01) with baseline insulin resistance. Those with a decrease in or an unchanged BMI z score had significantly greater insulin resistance than those whose BMI z score increased (mean [SD] HOMA, 6.2 [4.2] vs 2.6 [2.0], P < .01). Linear regression confirmed that HOMA was a significant predictor of change in BMI z score when controlling for age, race, and sex. CONCLUSIONS Among overweight children in primary care practices, a significant relationship was found between insulin resistance and the change in BMI z score associated with a dietitian-mediated intervention that includes a focus on decreasing sweetened beverage consumption. Estimating insulin resistance may inform dietary recommendations for overweight children.

Comparison of predictive equations and measured resting energy expenditure among obese youth attending a pediatric healthy weight clinic: one size does not fit all.

BACKGROUND The Academy of Nutrition and Dietetics recommends the use of indirect calorimetry for calculating caloric targets for weight loss in obese youth. Practitioners typically use predictive equations since indirect calorimetry is often not available. The objective of this study was to compare measured resting energy expenditure (MREE) with that estimated using published predictive equations in obese pediatric patients. MATERIAL AND METHODS Youth aged 7 to 18 years (n = 80) who were referred to a university-based healthy weight clinic and who were greater than the 95th percentile BMI for age and gender participated. MREE was measured via a portable indirect calorimeter. Predicted energy expenditure (pEE) was estimated using published equations including those commonly used in children. pEE was compared to the MREE for each subject. Absolute mean difference between MREE and pEE, mean percentage accuracy, and mean error were determined. RESULTS Mean percentage accuracy of pEE compared with MREE varied widely, with the Harris-Benedict, Lazzer, and Molnar equations providing the greatest accuracy (65%, 61%, and 60%, respectively). Mean differences between MREE and equation-estimated caloric targets varied from 197.9 kcal/day to 307.7 kcal/day. CONCLUSIONS The potential to either overestimate or underestimate calorie needs in the clinical setting is significant when comparing EE derived from predictive equations with that measured using portable indirect calorimetry. While our findings suggest that the Harris-Benedict equation has improved accuracy relative to other equations in severely obese youth, the potential for error remains sufficiently great to suggest that indirect calorimetry is preferred.

Medical nutrition therapy for overweight youth in their medical home: The KIDPOWER experience

OBJECTIVE To determine the feasibility and impact of implementing a standardized medical nutrition therapy (MNT) protocol to treat overweight children in their medical home. Primary outcomes evaluated were changes in eating behaviors, television habits, and weight status. METHODS A MNT protocol with handouts (known as KIDPOWER) was delivered by a registered dietitian (RD) to overweight children (2-20 years) in 9 primary care practices in a rural community. A medical record review yielded height, weight and selected patient/parent reported eating and TV behaviors from each MNT visit. Mean values were compared by paired samples t-tests. Changes in behaviors and BMI z score were compared using repeated measures ANOVA. RESULTS For patients with at least three MNT visits (n=109) significant improvements in eating and TV viewing habits were seen by the third visit. Weight status, as determined by a significant decline in mean BMI z score, was improved. CONCLUSION The KIDPOWER protocol delivered by a RD in the pediatric medical home aided overweight youth in making behavior changes that positively impacted their weight status. PRACTICE IMPLICATIONS Reimbursement to RDs for treating childhood obesity is improving and KIDPOWER provides a model and tools for community practice.

Determining the Accuracy and Reliability of Indirect Calorimeters Utilizing the Methanol Combustion Technique

BACKGROUND Several indirect calorimetry (IC) instruments are commercially available, but comparative validity and reliability data are lacking. Existing data are limited by inconsistencies in protocols, subject characteristics, or single-instrument validation comparisons. The aim of this study was to compare accuracy and reliability of metabolic carts using methanol combustion as the cross-laboratory criterion. METHODS Eight 20-minute methanol burn trials were completed on 12 metabolic carts. Respiratory exchange ratio (RER) and percent O2 and CO2 recovery were calculated. RESULTS For accuracy, 1 Omnical, Cosmed Quark CPET (Cosmed), and both Parvos (Parvo Medics trueOne 2400) measured all 3 variables within 2% of the true value; both DeltaTracs and the Vmax Encore System (Vmax) showed similar accuracy in measuring 1 or 2, but not all, variables. For reliability, 8 instruments were shown to be reliable, with the 2 Omnicals ranking best (coefficient of variation [CV] < 1.26%). Both Cosmeds, Parvos, DeltaTracs, 1 Jaeger Oxycon Pro (Oxycon), Max-II Metabolic Systems (Max-II), and Vmax were reliable for at least 1 variable (CV ≤ 3%). For multiple regression, humidity and amount of combusted methanol were significant predictors of RER (R2 = 0.33, P < .001). Temperature and amount of burned methanol were significant predictors of O2 recovery (R2 = 0.18, P < .001); only humidity was a predictor for CO2 recovery (R2 = 0.15, P < .001). CONCLUSIONS Omnical, Parvo, Cosmed, and DeltaTrac had greater accuracy and reliability. The small number of instruments tested and expected differences in gas calibration variability limits the generalizability of conclusions. Finally, humidity and temperature could be modified in the laboratory to optimize IC conditions.