OBJECTIVES: To provide updated prevalence data on obesity trends among US children and adolescents aged 2 to 19 years from a nationally representative sample. METHODS: We used the NHANES for years 1999 to 2016. Weight status was determined by using measured height and weight from the physical examination component of the NHANES to calculate age- and sex-specific BMI. We report the prevalence estimates of overweight and obesity (class I, class II, and class III) by 2-year NHANES cycles and compared cycles by using adjusted Wald tests and linear trends by using ordinary least squares regression. RESULTS: White and Asian American children have significantly lower rates of obesity than African American children, Hispanic children, or children of other races. We report a positive linear trend for all definitions of overweight and obesity among children 2–19 years old, most prominently among adolescents. Children aged 2 to 5 years showed a sharp increase in obesity prevalence from 2015 to 2016 compared with the previous cycle. CONCLUSIONS: Despite previous reports that obesity in children and adolescents has remained stable or decreased in recent years, we found no evidence of a decline in obesity prevalence at any age. In contrast, we report a significant increase in severe obesity among children aged 2 to 5 years since the 2013–2014 cycle, a trend that continued upward for many subgroups.

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This is a prepublication version of an article that has undergone peer review and been accepted for publication but is not the final version of record. This paper may be cited using the DOI and date of access. This paper may contain information that has errors in facts, figures, and statements, and will be corrected in the final published version. The journal is providing an early version of this article to expedite access to this information. The American Academy of Pediatrics, the editors, and authors are not responsible for inaccurate information and data described in this version.

BACKGROUNDEndometrial scratching (with the use of a pipelle biopsy) is a technique proposed to facilitate embryo implantation and increase the probability of pregnancy in women undergoing in vitro fertilization (IVF). METHODSWe conducted a pragmatic, multicenter, open-label, randomized, controlled trial. Eligible women were undergoing IVF (fresh-embryo or frozen-embryo transfer), with no recent exposure to disruptive intrauterine instrumentation (e.g., hysteroscopy). Participants were randomly assigned in a 1:1 ratio to either endometrial scratching (by pipelle biopsy between day 3 of the cycle preceding the embryotransfer cycle and day 3 of the embryo-transfer cycle) or no intervention. The primary outcome was live birth. RESULTSA total of 1364 women underwent randomization. The frequency of live birth was 180 of 690 women (26.1%) in the endometrial-scratch group and 176 of 674 women (26.1%) in the control group (adjusted odds ratio, 1.00; 95% confidence interval, 0.78 to 1.27). There were no significant between-group differences in the rates of ongoing pregnancy, clinical pregnancy, multiple pregnancy, ectopic pregnancy, or miscarriage. The median score for pain from endometrial scratching (on a scale of 0 to 10, with higher scores indicating worse pain) was 3.5 (interquartile range, 1.9 to 6.0). CONCLUSIONSEndometrial scratching did not result in a higher rate of live birth than no intervention among women undergoing IVF.

IMPORTANCE Physical activity in youth is associated with adult health. Understanding the prevalence and factors of moderate to vigorous physical activity among adolescents and young adults will guide public health and policy efforts. OBJECTIVES To describe the current patterns of physical activity and duration among adolescents and young adults and to identify the direction and magnitude of associations between physical activity and income, race/ethnicity, and sex. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional secondary data analysis used the self-reported physical activity data of adolescents and young adults from the National Health and Nutrition Examination Survey from 2007 through 2016. This data set is a multistage probability sample of the noninstitutionalized US population and allows estimates that represent the US population. The years 2007 through 2016 were selected because of the consistent physical activity questions during this period. Adolescents and young adults aged 12 to 29 years who responded to the survey were included. Individuals who were underweight were excluded. Data analysis was performed from October 17, 2017, to April 27, 2018. MAIN OUTCOMES AND MEASURES Self-reported physical activity duration and intensity. RESULTS Of the 9472 participants, 4771 (50.4%) were males, and the weighted mean age (range) was 20.6 (12-19) years. Across all demographic categories, females reported less physical activity than did their male counterparts. White adolescent males were most likely (89.3%; 95% CI, 86.5%-92.1%) and black females aged 18 to 24 years were least likely (45%; 95% CI, 39.0%-51.0%) to report any physical activity. Among those who were active, black males aged 18 to 24 years reported the longest duration of activity (77.9 minutes per day; 95% CI, 66.4-89.3 minutes per day), and black females aged 25 to 29 years reported the shortest duration of activity (33.2 minutes per day; 95% CI, 28.1-38.2 minutes per day). In adjusted models, younger age, white race, and higher income were associated with greater physical activity. CONCLUSIONS AND RELEVANCE Female adolescents and young adults were not meeting the recommended guidelines for physical activity, and substantial disparities by race and income levels were noted. These data highlight opportunities for targeted physical activity programming and policy efforts.

There is insufficient evidence of differences in live birth, miscarriage, stillbirth or clinical pregnancy to choose between TLS and conventional incubation. Further data explicitly comparing the incubation environment, the algorithm for embryo selection, or both, are required before recommendations for a change of routine practice can be justified.

Parent-directed text messages did not significantly change child BMI. However, texting significantly reduced attrition for treatment visits. Nearly all parents in this racially diverse, low-income sample engaged in daily text messaging, making this a feasible approach.

Objective Obesity and insulin resistance (IR) predispose to type 2 diabetes mellitus. Yet only half of obese adolescents have IR and far fewer progress to type 2 diabetes mellitus. We hypothesized that amino acid and fatty acid metabolites may serve as biomarkers or determinants of IR in obese teens. Research Design and Methods Fasting blood samples were analyzed by tandem mass spectrometry in 82 obese adolescents. A principal components analysis and multiple linear regression models were used to correlate metabolic components with surrogate measures of IR: homeostasis model assessment index of insulin resistance (HOMA-IR), adiponectin, and triglyceride (TG) to high-density lipoprotein (HDL) ratio. Results Branched-chain amino acid (BCAA) levels and products of BCAA catabolism were higher (P < .01) in males than females with comparable body mass index (BMI) z-score. In multivariate analyses, HOMA-IR in males correlated positively with BMI z-score and a metabolic signature containing BCAA, uric acid, and long-chain acylcarnitines and negatively with byproducts of complete fatty acid oxidation (R2 = 0.659, P < .0001). In contrast, only BMI z-score correlated with HOMA-IR in females. Adiponectin correlated inversely with BCAA and uric acid (R2 = 0.268, P = .0212) in males but not females. TG to HDL ratio correlated with BMI z-score and the BCAA signature in females but not males. Conclusions BCAA levels and byproducts of BCAA catabolism are higher in obese teenage boys than girls of comparable BMI z-score. A metabolic signature comprising BCAA and uric acid correlates positively with HOMA-IR in males and TG to HDL ratio in females and inversely with adiponectin in males but not females. Likewise, byproducts of fatty acid oxidation associate inversely with HOMA-IR in males but not females. Our findings underscore the roles of sex differences in metabolic function and outcomes in pediatric obesity.