Background Obesity (OB) is a serious epidemic in the United States. Methods We examined OB patterns and time trends across socio-economic and geographic parameters and projected the future situation. Large national databases were used. Overweight (OW), OB and severe obesity (SOB) were defined using body mass index cut-points/percentiles; central obesity (CO), waist circumference cut-point in adults and waist:height ratio cutoff in youth. Various meta-regression analysis models were fit for projection analyses. Results OB prevalence had consistently risen since 1999 and considerable differences existed across groups and regions. Among adults, men’s OB (33.7%) and OW (71.6%) levelled off in 2009–2012, resuming the increase to 38.0 and 74.7% in 2015–2016, respectively. Women showed an uninterrupted increase in OB/OW prevalence since 1999, reaching 41.5% (OB) and 68.9% (OW) in 2015–2016. SOB levelled off in 2013–2016 (men: 5.5–5.6%; women: 9.7–9.5%), after annual increases of 0.2% between 1999 and 2012. Non-Hispanic Blacks had the highest prevalence in women’s OB/SOB and men’s SOB. OB prevalence in boys rose continuously to 20.6% and SOB to 7.5% in 2015–2016, but not in girls. By 2030, most Americans will be OB/OW and nearly 50% of adults OB, whereas ∼33% of children aged 6–11 and ∼50% of adolescents aged 12–19 will be OB/OW. Since 1999, CO has risen steadily, and by 2030 is projected to reach 55.6% in men, 80.0% in women, 47.6% among girls and 38.9% among boys. Regional differences exist in adult OB prevalence (2011–2016) and across ethnicities; South (32.0%) and Midwest (31.4%) had the highest rates. Conclusions US obesity prevalence has been rising, despite a temporary pause in 2009–2012. Wide disparities across groups and geographical regions persist. Effective, sustainable, culturally-tailored interventions are needed.

Objectives Over the past three decades, twin studies have shown variation in the heritability of obesity. This study examined the difference of body mass index (BMI) heritability (BMI-H) by population characteristics, such as sex, age, time period of observation, and average BMI, as well as by broad social-environmental factors as indicated by country-level gross domestic product (GDP) per capita and GDP growth rate. Methods Twin studies that reported BMI-H and were published in English from Jan 1990 to Feb 2011 after excluding those with disease, special occupations or combined heritability estimates for country/ethnic groups were searched in PubMed. 32 studies were identified from Finland (7), the UK (6), the US (3), Denmark (3), China (3), Netherlands (2), South Korea (2), Sweden (2) and four from other countries. Meta regression models with random effect were used to access variation in BMI-H. Results Heterogeneity of BMI-H is significantly attributable to variations in age (<20yr, 20–55yr & ≥56yr), time period of observation (i.e., year of data collection), average BMI, and GDP (≤$20,000, $20,001–26,000 & >$26,000). BMI-H was higher in adolescents (<20yr), in studies done in past years, and in populations with higher average BMIs or higher GDP per capita (≥$26,000) than their counterparts. Consistent lowering effects of high GDP growth rate (>median) on BMI-H were shown through stratified analyses by GDP. BMI-H was lower in countries of mid-level GDP, particularly those experiencing rapid economic growth. Conclusions BMI-H is sensitive to age, time period of observation, average BMI, GDP, and rapid economic growth.

Childhood obesity has become a global epidemic. Parents can have an important influence on their children's health behaviors and weight status. Many studies have examined the association between parental and childhood weight status. However, much heterogeneity between studies exists, and the parent-child (P-C) association in obesity has varied. The purpose of this systematic examination and meta-analysis was to examine the strength and variation of the P-C association in obesity and to identify factors (e.g., demographic characteristics and country's economic level) that may influence this association. PubMed was searched for relevant studies published between January 2000 and July 2015. Thirty-two studies from 21 countries met inclusion criteria; 27 reported ORs for the P-C obesity association and were included in a meta-analysis. The meta-analysis showed a strong P-C obesity association (pooled OR: 2.22; 95% CI: 2.09, 2.36), which varied by type of P-C pair (i.e., parents-child, father-child, and mother-child), child age, parent and child weight status, and the country's economic level. Stronger associations were shown in older children than in younger children (β ± SE: 0.02 ± 0.01), in both parents than in father only (β ± SE: 0.51 ± 0.11) or mother only (β ± SE: 0.38 ± 0.11), in parental obesity (β ± SE: 0.26 ± 0.10) and child obesity (β ± SE: 0.28 ± 0.12) than in parental and child overweight, and in high- than in middle-income countries (β ± SE: 0.23 ± 0.08). Thus, research from multiple countries shows significant P-C associations in weight status, but this association varies by child age, type of P-C pair, weight status, and the country's economic level. Results suggest that families and parents should be a key target for obesity intervention efforts.

Previous research has shown associations between brain structure and resting state high-frequency heart rate variability (HF-HRV). Age affects both brain structure and HF-HRV. Therefore we sought to examine the relationship between brain structure and HF-HRV as a function of age. Data from two independent studies were used for the present analysis. Study 1 included 19 older adults (10 males, age range 62–78 years) and 19 younger adults (12 males, age range 19–37). Study 2 included 23 older adults (12 males; age range 55–75) and 27 younger adults (17 males; age range 18–34). The root-mean-square of successive R-R-interval differences (RMSSD) from ECG recordings was used as time-domain measure of HF-HRV. MRI scans were performed on a 3.0-T Siemens Magnetom Trio scanner. Cortical reconstruction and volumetric segmentation were performed with the Freesurfer image analysis suite, including 12 regions as regions-of-interests (ROI). Zero-order and partial correlations were used to assess the correlation of RMSSD with cortical thickness in selected ROIs. Lateral orbitofrontal cortex (OFC) cortical thickness was significantly associated with RMSSD. Further, both studies, in line with previous research, showed correlations between RMSSD and anterior cingulate cortex (ACC) cortical thickness. Meta-analysis on adjusted correlation coefficients from individual studies confirmed an association of RMSSD with the left rostral ACC and the left lateral OFC. Future longitudinal studies are necessary to trace individual trajectories in the association of HRV and brain structure across aging.

Background Diabetes and obesity have become epidemics and costly chronic diseases. The impact of mobile health (mHealth) interventions on diabetes and obesity management is promising; however, studies showed varied results in the efficacy of mHealth interventions. Objective This review aimed to evaluate the effectiveness of mHealth interventions for diabetes and obesity treatment and management on the basis of evidence reported in reviews and meta-analyses and to provide recommendations for future interventions and research. Methods We systematically searched the PubMed, IEEE Xplore Digital Library, and Cochrane databases for systematic reviews published between January 1, 2005, and October 1, 2019. We analyzed 17 reviews, which assessed 55,604 original intervention studies, that met the inclusion criteria. Of those, 6 reviews were included in our meta-analysis. Results The reviews primarily focused on the use of mobile apps and text messaging and the self-monitoring and management function of mHealth programs in patients with diabetes and obesity. All reviews examined changes in biomarkers, and some reviews assessed treatment adherence (n=7) and health behaviors (n=9). Although the effectiveness of mHealth interventions varied widely by study, all reviews concluded that mHealth was a feasible option and had the potential for improving patient health when compared with standard care, especially for glycemic control (−0.3% to −0.5% greater reduction in hemoglobin A1c) and weight reduction (−1.0 kg to −2.4 kg body weight). Overall, the existing 6 meta-analysis studies showed pooled favorable effects of these mHealth interventions (−0.79, 95% CI −1.17 to −0.42; I2=90.5). Conclusions mHealth interventions are promising, but there is limited evidence about their effectiveness in glycemic control and weight reduction. Future research to develop evidence-based mHealth strategies should use valid measures and rigorous study designs. To enhance the effectiveness of mHealth interventions, future studies are warranted for the optimal formats and the frequency of contacting patients, better tailoring of messages, and enhancing usability, which places a greater emphasis on maintaining effectiveness over time.

SummaryObjective: This systematic examination and meta-analysis examined the scope and variation of the worldwide double burden of diseases and identified related socio-demographic factors.Design: We searched PubMed for studies published in English from January 1, 2000, through September 28, 2016, that reported on double disease burden. Twenty-nine studies from 18 high-income, middle-income and low-income countries met inclusion criteria and provided 71 obesity-undernutrition ratios, which were included in meta-regression analysis.Results: All high-income countries had a much higher prevalence of obesity than undernutrition (i.e. all the obesity/undernutrition ratios >1); 55% of the ratios in lower middle-income and low-income countries were <1, but only 28% in upper middle-income countries. Meta-analysis showed a pooled obesity-undernutrition ratio of 4.3 (95% CI = 3.1-5.5), which varied by country income level, subjects' age and over time. The average ratio was higher in high-income rather than that in lower middle-income and low-income countries Conclusions: There are considerable differences in the obesity versus undernutrition ratios and in their prevalence by country income level, age groups and over time, which may be a consequence of the cumulative exposure to an obesogenic environment.

The locus coeruleus (LC) is a key node of the sympathetic nervous system and suppresses parasympathetic activity that would otherwise increase heart rate variability. In the current study, we examined whether LC-MRI contrast reflecting neuromelanin accumulation in the LC was associated with high-frequency heart rate variability (HF-HRV), a measure reflecting parasympathetic influences on the heart. Recent evidence indicates that neuromelanin, a byproduct of catecholamine metabolism, accumulates in the LC through young and mid adulthood, suggesting that LC-MRI contrast may be a useful biomarker of individual differences in habitual LC activation. We found that, across younger and older adults, greater LC-MRI contrast was negatively associated with HF-HRV during fear conditioning and spatial detection tasks. This correlation was not accounted for by individual differences in age or anxiety. These findings indicate that individual differences in LC structure relate to key cardiovascular parameters.

Objective Previous studies in China showed large sex differences in childhood overweight and obesity (ow/ob) rates. However, limited research has examined the cause of these sex differences. This study aimed to examine individual and parental/familial factors associated with sex differences in childhood ow/ob rates in China. Design Variables associated with child weight status, beliefs and behaviors, and obesity-related parenting practices were selected to examine their sex differences and association with a sex difference in child ow/ob outcomes using logistic regression analysis. Setting Cross-sectional data analysis using the 2011 China Health and Nutrition Survey. Subjects Children aged 6–17 years (n=1,544) and their parents. Results Overall child ow/ob prevalence was 16.8%. Adolescent boys (AB; 12–17 years) were about twice as likely to be ow/ob as adolescent girls (AG; 15.5 vs. 8.4%, p<0.05). AB more likely had energy intake exceeding recommendations, self-perceived underweight, underestimated their body weight, and were satisfied with their physical activity level than AG. AG more likely practiced weight loss management through diet and self-perceived overweight than AB. Mothers more likely identified AG’s weight accurately but underestimated AB’s weight. Stronger associations with risk of childhood ow/ob were found in boys than girls in dieting to lose weight (OR= 6.7 in boys vs. 2.6 in girls) and combined maternal and child perception of the child’s overweight (OR= 35.4 in boys vs. 14.2 in girls). Conclusions Large sex differences in childhood obesity may be related to the sex disparities in weight-related beliefs and behaviors among children and their parents in China.