Total Body Adiposity Research Articles

Effects of volume-matched once-weekly and thrice-weekly high-intensity interval training (HIIT) on body adiposity in adults with central obesity: Study protocol for a randomized controlled trial

ObjectiveThis study aims to examine the comparative effects of 75 min of volume-matched once-weekly and thrice-weekly high-intensity interval training (HIIT) on body adiposity in adults with central obesity. MethodsThis assessor-blinded, three-arm, randomized controlled trial will recruit 315 physically inactive adults with central obesity (aged ≥18 years, body mass index ≥23, waist circumference ≥90 cm for men and ≥80 cm for women). Participants will be randomly allocated to the once-weekly HIIT, thrice-weekly HIIT or usual care control group. Participants in the HIIT groups will receive weekly exercise training sessions for 16 weeks, prescribed either once or three times weekly. Each HIIT session will consist of a supervised program of four 4-min high-intensity intervals at 85%–95% peak heart rate (HRpeak) interspersed with 3-min active recovery intervals at 50%–70% HRpeak. Participants in the once-weekly HIIT group will perform the 25-min HIIT bout three times with a break between each 25-min HIIT bout. The usual care control group will receive bi-weekly health education classes. The outcome assessments will be conducted at baseline, 16 weeks (post-intervention) and 32 weeks (follow-up). The primary outcome will be total body adiposity assessed by dual-energy X-ray absorptiometry (DXA). The secondary outcome measures will include markers of cardiovascular and metabolic health (body composition, cardiorespiratory fitness, blood pressure, and blood lipids), mental health, cognitive performance, health-related quality of life, sleep quality, habitual physical activity, diet, medication, adverse events and adherence to the intervention. Impact of the projectThe findings from this study are expected to consolidate the therapeutic efficacy of HIIT for the management of central obesity and inform the comparative compliance, feasibility and suitability of once-weekly and thrice-weekly HIIT as exercise strategies to manage obesity. In particular, the present study is expected to provide a novel perspective on the utility of low-frequency HIIT (i.e., once-weekly) as an effective and sustainable exercise strategy to tackle the obesity pandemic. The anticipated findings will hold substantial translational value by informing public health policies and enhancing exercise compliance in the physically inactive obese population. Trial registrationClinicalTrials.gov (NCT04887454).

Abstract P151: Increased Gain of Skeletal Muscle Adiposity in Middle-Aged African Caribbean Men With Type 2 Diabetes

While type 2 diabetes (T2D) is a known risk factor for the acceleration of muscle loss with aging, less is known about the impact of T2D on skeletal muscle fat infiltration (i.e., myosteatosis) and overall adiposity. Myosteatosis increases with aging, is greater in African as compared to European ancestry individuals, and plays an important role in the development of T2D. Thus, we investigated the association of T2D with changes in body adiposity distribution, with a particular interest in myosteatosis. T2D was identified by self-report, use of hypoglycemic agents, or fasting glucose levels of ≥ 126 mg/dL. Longitudinal changes in computed tomography-measured calf skeletal muscle density [as an inverse surrogate measure of intramuscular adiposity (mg/cm 3 )] and dual-energy X-ray absorptiometry-measured regional and whole body fat were examined by T2D status over an average of 6 years in 724 African-Caribbean men aged 40-54 years from the Tobago Health Study. Total body, arm, leg, and trunk adiposity increased to a significantly greater extent among men without compared to with T2D. In contrast, men with T2D had a 1.6 times greater decrease in calf skeletal muscle density compared with their non-diabetic counterparts (p=0.03). T2D is associated with lower gains in general adiposity, but an increased gain in skeletal muscle adiposity among middle aged African Caribbean men. Our novel findings suggest that middle-aged African Caribbean men with T2D might be at especially high risk for increased gain of myosteatosis. Interventions targeted for men in this age group could focus on controlling diabetes, slowing myosteatosis, and promoting healthy aging.

Equations for Prediction of Body Adiposity in Patients With Chronic Kidney Disease Undergoing Hemodialysis

The prevalence of obesity in the population has increased and excess body adiposity is one of the main nutritional disorders in patients with chronic kidney disease (CKD) on hemodialysis (HD). The objective of this study was to develop equations using anthropometric measurements to predict the total and abdominal body adiposity of patients with CKD on HD. This is a cross-sectional study evaluating 323 patients with CKD on HD in city in northeastern Brazil. Measurements and anthropometric indicators were correlated with percentage of body fat (%BF) and visceral fat (VF, in kg) measured by dual energy X-ray absorptiometry. Multiple linear regression models based on different combinations of anthropometric measurements were adjusted to develop the equations, with subsequent cross-validation. Of the 323 patients, 62.2% were male and 46.5% were aged between 40 and 59years. The equation selected to estimate %BF included weight, height, waist and hip circumferences, and triceps and suprailiac skin folds, presenting high predictive capacity (R2=0.771). The equation selected to estimate VF included weight, height, waist circumference, hip circumference, and sum of skin folds (R22=0.796). The proposed equations efficiently predicted the %BF and VF (kg) of patients with CKD on HD, thereby serving as viable indicators in clinical practice.

Type 2 diabetes mellitus in obesity promotes prolongation of cardiomyocyte contractile function, impaired Ca2+ handling and protein carbonylation damage

AimsTo investigate whether the obesity associated to T2DM presented cardiomyocyte myocardial contractility dysfunction due to damage in Ca2+ handling, concomitantly with increased biomarkers of oxidative stress. MethodsMale Wistar rats were randomized into two groups: control (C): fed with standard diet; and obese (Ob) that fed a saturated high-fat. After the characterization of obesity (12 weeks), the Ob animals were submitted to T2DM induction with a single dose of intraperitoneal (i.p.) injection of streptozotocin (30 mg/kg). Thus, remained Ob rats that were characterized as to the presence (T2DMOb; n = 8) and/or absence (Ob; n = 10) of T2DM. Cardiac remodeling was measured by post-mortem morphological, isolated cardiomyocyte contractile function, as well as by intracellular Ca2+-handling analysis. ResultsT2DMOb presented a significant reduction of all fat pads, total body fat and adiposity index. T2DMOb group presented a significant increase in protein carbonylation and superoxide dismutase (SOD) activity, respectively. T2DMOb promoted elevations in fractional shortening (15.6 %) and time to 50 % shortening (5.8 %), respectively. Time to 50 % Ca2+ decay was prolonged in T2DMOb, suggesting a possible impairment in Ca2+recapture and/or removal. ConclusionType 2 diabetes mellitus in obesity promotes prolongation of cardiomyocyte contractile function with protein carbonylation damage and impaired Ca2+ handling.

Association of Hepatic Steatosis with Adipose and Muscle Mass and Distribution in Children.

Background: Pediatric studies have shown associations between hepatic steatosis and total body fat, visceral fat, and lean mass. However, these associations have not been assessed simultaneously, leaving their relative importance unknown. Objective: To evaluate associations between hepatic steatosis and total-body adiposity, visceral adiposity, and lean mass in children. Method: In children at risk for fatty liver, hepatic steatosis, adipose, and lean mass were estimated with magnetic resonance imaging and dual-energy X-ray absorptiometry. Results: Two hundred twenty-seven children with mean age 12.1 years had mean percent body fat of 38.9% and mean liver fat of 8.4%. Liver fat was positively associated with total-body adiposity, visceral adiposity, and lean mass (P < 0.001), and negatively associated with lean mass percentage (P < 0.001). After weight adjustment, liver fat was only positively associated with measures of central adiposity (P < 0.001). Visceral adiposity also had the strongest association with liver fat (P < 0.001). Conclusions: In children, hepatic steatosis is more strongly associated with visceral adiposity than total adiposity, and the association of lean mass is not independent of weight or fat mass. These relationships may help guide the choice of future interventions to target hepatic steatosis.

Associations of food reinforcement and food- related inhibitory control with adiposity and weight gain in children and adolescents

Some, but not all studies have reported that, among youth with disordered eating and high weight, the relative reinforcing value of food (RRV-F, i.e., how hard a person will work for a high-energy-dense food when another reward is available) is greater, and food-related inhibitory control (i.e., ability to withhold a response to food-related stimuli) is lower, compared to peers without disordered eating or overweight. In most studies, high RRV-F and low food-related inhibitory control have been studied separately, as independent factors, with each suggested to predict excess weight and adiposity (fat mass) gain. We hypothesized that the interaction of these factors would prospectively exacerbate risk for weight and adiposity (fat mass) gain three years later in a sample of healthy youth. At baseline, RRV-F was measured using a Behavior Choice Task with the rewards being standardized servings of chocolate candies, cheese crackers, or fruit snacks. Food-related inhibitory control was determined by performance in response to food and non-food stimuli during a Food Go/No-Go task. At baseline and 3-year visits, total body adiposity was measured by dual-energy X-ray absorptiometry (DXA) and body mass index (BMI) was obtained using measured weight and height. A linear regression was conducted with 3-year adiposity as the dependent variable. RRV-F, food-related inhibitory control, and the RRV-F x food-related inhibitory control interaction as independent variables. Baseline adiposity, age, height, sex, race/ethnicity, and days between visits were included as covariates for model predicting 3-year adiposity. Baseline BMI, age, sex, race/ethnicity, and days between visits were included as covariates for model predicting 3-year BMI. One-hundred and nine youth (mean 12.4±2.7y, mean 0.50±1.02 BMIz, 30.3% with overweight/obesity, 45.9% female, 51.4% non-Hispanic White), 8–17 years at baseline, were studied. Baseline food-related inhibitory control (βunstandardized = 0.33, p = .037, 95% CI [.02, 0.64]), but not baseline RRV-F (βunstandardized = -0.003, p = .914), 95% CI [-0.05, 0.05]) was significantly associated with 3-year adiposity such that those with the poorest food-related inhibitory control (great number of commision errors) had the greatest adiposity gain. The interaction between RRV-F and food-related inhibitory control did not predict 3-year adiposity (βunstandardized = -0.07, p = .648, 95% CI [-0.39, 0.25]). The pattern of findings was the same for models examining non-food related inhibitory control. Neither baseline food-related inhibitory control (βunstandardized = 2.16, p = .256, 95% CI [-1.59, 5.92]), baseline RRV-F (βunstandardized = 0.14, p = .660, 95% CI [-0.48, 0.75]), nor their interaction (βunstandardized = -1.18, p = .547, 95% CI [-5.04, 2.69]) were significantly associated with 3-year BMI. However, non-food related inhibitory control (βunstandardized = 0.54, p = .038, 95% CI [.22, 7.15]) was significantly associated with 3-year BMI. In summary, food-related inhibitory control but not RRV-F, was associated with changes in adiposity in a sample of children and adolescents. Among generally healthy youth, food-related inhibitory control may be a more relevant risk factor than food reinforcement for adiposity gain. Additional data are needed to determine how inhibitory control and reward systems, as well as other disinhibited eating behaviors/traits, may interact to promote excess weight gain over time in youth.

Morning Serum Cortisol Is Uniquely Associated with Cardiometabolic Risk Independent of Body Composition in Latino Adolescents.

Background: Alterations in morning serum cortisol (MSC) have been associated with higher cardiometabolic risk. This finding has been documented primarily in populations with overweight or obesity; however, it has not been clearly established if obesity plays a requisite role in this relationship. This study seeks to extend earlier findings by examining whether body composition measures alter the relationship between MSC with glucose and insulin markers, blood pressure, and lipid parameters in Latino youth in middle adolescence. Methods: This cross-sectional study included 196 healthy adolescents (130F/66M; mean age: 16.4 ± 0.6 years; 95% Latino; mean body mass index, BMI: 24.3 ± 5.7) from Los Angeles, California. Morning cortisol, glucose, insulin, glycated hemoglobin, and lipids (triglycerides and high-density lipoprotein cholesterol) were assessed from a fasting blood sample. Sitting systolic and diastolic blood pressure was averaged from duplicate measures. Body composition measures included BMI and waist circumference, which were used as proxies for total body and abdominal adiposity, respectively. Triplicate measurements of weight and height were averaged for calculation of BMI; age- and sex-specific BMI z-score was used to classify into normal BMI or overweight/obese BMI status. Waist circumference was measured in duplicate and the average was used to classify participants into two strata: normal/healthy waist circumference (<90th percentile for age, sex, and ethnicity) and high waist circumference (≥90th percentile). Results: The primary findings were that higher MSC was associated with higher fasting glucose and systolic blood pressure after adjusting for age, sex, and BMI z-score (and/or waist circumference). BMI status or waist circumference status did not alter these relationships. Main Conclusion: Our results suggest that the relationships between hypothalamic-pituitary-adrenal axis function and certain cardiometabolic risk factors may be independent of adiposity. Future research is warranted to discover the contributors and underlying mechanisms of these relationships in adolescent populations. ClinicalTrials.gov identifier: NCT02088294.

Differences between HbA1c and glucose-related variables in predicting weight loss and glycaemic changes in individuals with overweight and hyperglycaemia – The PREVIEW trial

To examine the differences between HbA1c and glucose related variables in predicting weight loss and glycaemic changes following 8 weeks of low energy diet (LED) in individuals with overweight and hyperglycaemia. 2178 individuals with ADA-defined pre-diabetes - impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) - who started an 8 week LED weight loss diet, were included in this analysis. Participants were enrolled in the PREVIEW (PREVention of diabetes through lifestyle interventions and population studies In Europe and around the World) clinical trial. Multivariable linear mixed effects regression models and generalised additive mixed effect logistic models were used. Only 1 in 3 participants (33%) had HbA1c levels defined as pre-diabetes. Neither baseline HbA1c, IFG or IGT were associated with body weight change at 8 weeks. Higher baseline body weight, baseline fasting insulin and weight loss predicted normalisation of fasting plasma glucose (FPG), whilst higher baseline fasting insulin, C-reactive protein (hsCRP) and older age predicted normalisation of HbA1c. Additionally, male sex and higher baseline BMI, body fat and energy intake were positively associated with weight loss, whereas greater age and higher HDL-cholesterol predicted less weight loss. Whilst neither HbA1c nor fasting glucose predicts short-term weight loss success, both may impact the metabolic response to rapid weight loss. We propose a role of inflammation versus total body adiposity since these variables are independent predictors of the normalisation of HbA1c and fasting glucose, respectively.

Chronic Intermittent Hypoxia during Sleep Causes Browning of Interscapular Adipose Tissue Accompanied by Local Insulin Resistance in Mice

Obstructive sleep apnea (OSA) is a highly prevalent condition, characterized by intermittent hypoxia (IH), sleep disruption, and altered autonomic nervous system function. OSA has been independently associated with dyslipidemia, insulin resistance, and metabolic syndrome. Brown adipose tissue (BAT) has been suggested as a modulator of systemic glucose tolerance through adaptive thermogenesis. Reductions in BAT mass have been associated with obesity and metabolic syndrome. No studies have systematically characterized the effects of chronic IH on BAT. Thus, we aimed to delineate IH effects on BAT and concomitant metabolic changes. C57BL/6J 8-week-old male mice were randomly assigned to IH during sleep (alternating 90 s cycles of 6.5% FIO2 followed by 21% FIO2) or normoxia (room air, RA) for 10 weeks. Mice were subjected to glucose tolerance testing and 18F-FDG PET-MRI towards the end of the exposures followed by BAT tissues analyses for morphological and global transcriptomic changes. Animals exposed to IH were glucose intolerant despite lower total body weight and adiposity. BAT tissues in IH-exposed mice demonstrated characteristic changes associated with "browning"-smaller lipids, increased vascularity, and a trend towards higher protein levels of UCP1. Conversely, mitochondrial DNA content and protein levels of respiratory chain complex III were reduced. Pro-inflammatory macrophages were more abundant in IH-exposed BAT. Transcriptomic analysis revealed increases in fatty acid oxidation and oxidative stress pathways in IH-exposed BAT, along with a reduction in pathways related to myogenesis, hypoxia, and IL-4 anti-inflammatory response. Functionally, IH-exposed BAT demonstrated reduced absorption of glucose on PET scans and reduced phosphorylation of AKT in response to insulin. Current studies provide initial evidence for the presence of a maladaptive response of interscapular BAT in response to chronic IH mimicking OSA, resulting in a paradoxical divergence, namely, BAT browning but tissue-specific and systemic insulin resistance. We postulate that oxidative stress, mitochondrial dysfunction, and inflammation may underlie these dichotomous outcomes in BAT.

Physical Behaviors and Their Association With Adiposity in Men and Women From a Low-Resourced African Setting.

We first explored the associations between physical behaviors and total and regional adiposity. Second, we examined how reallocating time in different physical behaviors was associated with total body fat mass in men and women from a low-income South African setting. This cross-sectional study included a sample of 692 participants (384 men and 308 women) aged 41-72 years. Physical behaviors were measured using integrated hip and thigh accelerometry to estimate total movement volume and time spent in sleeping, sitting/lying, standing, light physical activity, and moderate to vigorous physical activity (MVPA). Total body fat mass and regional adiposity were measured using dual-energy X-ray absorptiometry. The associations between total movement volume and measures of regional obesity were mediated by total body adiposity. In men, reallocating 30 minutes of sitting/lying to 30 minutes of MVPA was associated with 1.0% lower fat mass. In women, reallocation of 30 minutes of sitting/lying to MVPA and 30 minutes of standing to MVPA were associated with a 0.3% and 1.4% lower fat mass, respectively. Although the association between physical behaviors and fat mass differed between men and women, the overall public health message is similar; reallocating sedentary time to MVPA is associated with a reduction in fat mass in both men and women.

Adiposity Assessment with a Novel Portable Ultrasound Device

ObjectivesUltrasound (US) systems are increasingly being used to quantify total body and regional adiposity (Epub 2015. PMID: 26,740,255) along with providing estimates of muscle fat infiltration (echogenicity; Epub 2020. PMID: 33,111,338). The aim of the current study was to evaluate the feasibility of a small, relatively low-cost ultrasound device (ButterflyIQ; Butterfly Network, Guilford, CT) that interfaces with an iPad to assess total body fat quantified with dual-energy X-ray absorptiometry (DXA).MethodsParticipants were a convenience sample of 59 healthy adults who were diverse in age, ethnicity, and adiposity. Total and regional fat masses were measured using DXA (Hologic, Marlborough, MA). Fat thicknesses were taken using the Butterfly at two points on the right thigh. Echogenicity of the rectus femoris was also determined using ImageJ (NIH, Bethesda, MD). Regression analysis was used to evaluate the associations between US-derived fat thickness and DXA-measured total body and leg fat mass. Correlations were also examined between US echogenicity and phase angle at 50 kHz (InBody S10; Seoul, South Korea), an established method for estimating muscle quality.ResultsOf the 59 participants, 2 females and 1 male were excluded due to low US image quality. Mid-thigh US adipose tissue layer thickness showed the strongest correlations (R2s) with total and right leg fat mass: females, 0.80 and 0.87; males, 0.56 and 0.53 (all p < 0.001). Corresponding correlations at the third-thigh site were smaller in magnitude (0.68 and 0.79; 0.41 and 0.37). A significant (p < 0.05) inverse relationship (R2, 0.10) was present between US echogenicity and phase angle at 50 kHz.ConclusionsThe evaluated small and portable US device has the important potential to phenotype adiposity and muscle quality in clinical and field settings that lack availability of larger, more costly, and complex measurement systems.Funding SourcesThis work was partially supported by National Institutes of Health NORC Center Grants P30DK072476, Pennington/Louisiana; and P30DK040561, Harvard; and R01DK109008, Shape UP! Adults.

Total and regional body adiposity increases during menopause-evidence from a follow-up study.

For women, menopausal transition is a time of significant hormonal changes, which may contribute to altered body composition and regional adipose tissue accumulation. Excess adiposity, and especially adipose tissue accumulation in the central body region, increases women's risk of cardiovascular and metabolic conditions and affects physical functioning. We investigated the associations between menopausal progression and total and regional body adiposity measured with dual‐energy X‐ray absorptiometry and computed tomography in two longitudinal cohort studies of women aged 47–55 (n = 230 and 148, mean follow‐up times 1.3 ± 0.7 and 3.9 ± 0.2 years, mean baseline BMI 25.5 kg/m2). We also examined associations between menopausal progression and skeletal muscle fiber characteristics, as well as adipose tissue‐derived adipokines. Relative increases of 2%–14% were observed in regional and total body adiposity measures, with a pronounced fat mass increase in the android area (4% and 14% during short‐ and long‐term follow‐ups). Muscle fiber oxidative and glycolytic capacities and intracellular adiposity were not affected by menopause, but were differentially correlated with total and regional body adiposity at different menopausal stages. Menopausal progression and regional adipose tissue masses were positively associated with serum adiponectin and leptin, and negatively associated with resistin levels. Higher diet quality and physical activity level were also inversely associated with several body adiposity measures. Therefore, healthy lifestyle habits before and during menopause might delay the onset of severe metabolic conditions in women.

Effects of one-year once-weekly high-intensity interval training on body adiposity and liver fat in adults with central obesity: Study protocol for a randomized controlled trial

Background/ObjectivesThis study aims to examine the effects of one-year, once-weekly high-intensity interval training (HIIT) on body adiposity and liver fat in adults with central obesity. MethodsOne-hundred and twenty adults aged 18–60 years with central obesity (body mass index ≥25, waist circumference ≥90 cm for men and ≥80 cm for women). This is an assessor-blinded randomized controlled trial. Participants will be randomly assigned to the HIIT group or the usual care control group. Each HIIT session will consist of 4 × 4-min bouts at 85%–95% maximal heart rate, interspersed with 3-min bouts at 50%–70% maximal heart rate. The HIIT group will complete one session per week for 12 months, whereas the usual care control group will receive health education. The primary outcomes of this study are total body adiposity and intrahepatic triglyceride content. The secondary outcomes include abdominal visceral adipose tissue, subcutaneous adipose tissue, body mass index, waist circumference, hip circumference, cardiorespiratory fitness, lean body mass, bone mineral density, blood pressure, fasting blood glucose, insulin, triglycerides, glycated hemoglobin, cholesterol profile, liver function enzymes, medications, adherence to exercise, adverse events, quality of life, and mental health. Outcome measure will be conducted at baseline, 12 months (post-intervention), and 24 months (one-year follow-up). Impact of the projectThis study will explore the benefits of long-term once-weekly HIIT with a follow-up period to assess its effectiveness, adherence, and sustainability. We expect this intervention will enhance the practical suitability of HIIT in inactive adults with central obesity, and provide insights on low-frequency HIIT as a novel exercise option for the management of patients with central obesity and liver fat. Trial registrationClinicalTrials.gov (NCT03912272) registered on 11 April 2019.

Randomized controlled trial for time-restricted eating in healthy volunteers without obesity

Time-restricted feeding (TRF) improves metabolic health. Both early TRF (eTRF, food intake restricted to the early part of the day) and mid-day TRF (mTRF, food intake restricted to the middle of the day) have been shown to have metabolic benefits. However, the two regimens have yet to be thoroughly compared. We conducted a five-week randomized trial to compare the effects of the two TRF regimens in healthy individuals without obesity (ChiCTR2000029797). The trial has completed. Ninety participants were randomized to eTRF (n=30), mTRF (n=30), or control groups (n=30) using a computer-based random-number generator. Eighty-two participants completed the entire five-week trial and were analyzed (28 in eTRF, 26 in mTRF, 28 in control groups). The primary outcome was the change in insulin resistance. Researchers who assessed the outcomes were blinded to group assignment, but participants and care givers were not. Here we show that eTRF was more effective than mTRF at improving insulin sensitivity. Furthermore, eTRF, but not mTRF, improved fasting glucose, reduced total body mass and adiposity, ameliorated inflammation, and increased gut microbial diversity. No serious adverse events were reported during the trial. In conclusion, eTRF showed greater benefits for insulin resistance and related metabolic parameters compared with mTRF. Clinical Trial Registration URL: http://www.chictr.org.cn/showproj.aspx?proj=49406.

Retrieval-induced forgetting in children and adolescents with and without obesity.

Background/objectives:Previous research indicates that youth with obesity exhibit deficits in executive functioning (EF), which often take the form of impaired response inhibition. One aspect of EF not previously studied in obesity is the adaptive process known as retrieval-induced forgetting (RIF), the suppression/inhibition of intrusive or non-target items by the retrieval of specific items from memory. The present study investigated if child or adolescent obesity disrupts the ability to inhibit retrieval of intrusive memories.Subjects/methods:We compared the manifestation of RIF in children (ages 8–12) and adolescents (ages 13–18) as a function of their weight status and sex. We also evaluated the effects of these variables on simple recall of items from episodic memory under conditions where competition from intrusive items was reduced.Results:Children with obesity did not demonstrate significant RIF, whereas RIF was exhibited by preteens without obesity and by teenage participants with- and without obesity (x Weight Status x Age Group interaction p = 0.028). This pattern of results did not differ as a function of sex for either age group. No differences in episodic memory were found. Additional analyses using Age as continuous covariate (and not as a nominal group) comparing participants who exhibited RIF with those who did not, found that the no RIF group consumed fast-food meals more frequently (p=.024) and had higher percentages of total body adiposity and android fat compared to the RIF group (p’s<.05).Conclusions:The findings expand what is known about the effects of childhood obesity on cognitive functioning, identify impaired RIF with specific behavioral and dietary factors and increased adiposity, and suggest the possibility that impairments in the ability to inhibit intrusive memories of food and eating may contribute to poor early-life weight control.

Epicardial and Perihepatic Fat as Cardiometabolic Risk Predictors in Girls with Turner Syndrome: A Cardiac Magnetic Resonance Study

Objective:Turner syndrome (TS) patients are at high risk of cardiometabolic disorders. Cardiometabolic risk factors are more commonly related to visceral rather than total body adiposity. Adipocytokines have been explored as a potential link between obesity and obesity-related cardiometabolic dysfunction. This study explored the validity of epicardial fat-thickness (EFT) and perihepatic fat-thickness (PHFT) measurement as cardiometabolic-risk predictors in TS-girls in relation to standard obesity-indices and metabolic syndrome (MetS) components.Methods:Forty-six TS girls and twenty-five controls (10-16 years) were subdivided into two age-groups (10 to less than 13 and 13-16). Participants were assessed for body mass index (BMI) Z-scores, waist circumference (WC), total-fat mass (FM) and trunk-FM by bioimpedance-technique, EFT and PHFT by cardiovascular magnetic resonance, lipid-profile, homeostasis model assessment of insulin resistance (HOMA-IR), and serum chemerin. MetS was defined according to International Diabetes Federation criteria.Results:Overweight/obesity and MetS were detected in 45.7% and 37% of TS-girls respectively. BMI Z-score, WC, total-FM, trunk-FM, EFT and PHFT values were significantly higher in TS-age groups compared to age-matched control groups, being more pronounced in the older group when TS-girls had been exposed to estrogen. Dyslipidemia, higher HOMA-IR, chemerin, EFT and PHFT values were observed in lean-Turner compared to BMI-Z-matched controls. EFT and PHFT were significantly correlated with chemerin and several components of MetS. EFT at a cut-off-value of 6.20 mm (area under the curve=0.814) can predict MetS in TS-girls.Conclusion:TS-girls displayed an adverse cardiometabolic profile during late childhood and adolescence. EFT and PHFT are emerging cardiometabolic risk predictors in TS-patients. Excess EFT rather than total body adiposity may contribute to altered metabolic profile among lean-Turner patients.

Time-Restricted Feeding during Puberty Ameliorates Adiposity and Prevents Hepatic Steatosis in a Mouse Model of Childhood Obesity.

Background: Time restricted feeding (TRF) refers to dietary interventions in which food access is limited during a specific timeframe of the day. TRFs have proven useful in improving metabolic health in adult subjects with obesity. Their beneficial effects are mediated, in part, through modulating the circadian rhythm. Nevertheless, the translation of these dietary interventions onto obese/overweight children and adolescents remains uncharacterized. The objective of this study is to explore the feasibility of temporal dietary interventions for improving metabolic health in the context of childhood obesity. Methods: We have previously developed a mouse model of early adiposity (i.e., childhood obesity) through litter size reduction. Mice raised in small litters (SL) became obese as early as by two weeks of age, and as adults, they developed several obesity-related co-morbidities, including insulin resistance, glucose intolerance and hepatic steatosis. Here, we explored whether two independent short-term chrono-nutritional interventions might improve metabolic health in 1-month-old pre-pubertal SL mice. Both TRFs comprised 8 h feeding/14 h fasting. In the first one (TRF1) Control and SL mice had access to the diet for 8 h during the dark phase. In the second intervention (TRF2) food was available during the light:dark transitions. Results: TRF1 did not alter food intake nor ameliorate adiposity in SL-TRF1. In contrast, SL-TRF2 mice showed unintentional reduction of caloric intake, which was accompanied by reduced total body weight and adiposity. Strikingly, hepatic triglyceride content was completely normalized in SL-TRF1 and SL-TRF2 mice, when compared to the ad lib-fed SL mice. These effects were partially mediated by (i) clock-dependent signals, which might modulate the expression of Pparg or Cpt1a, and (ii) clock-independent signals, such as fasting itself, which could influence Fasn expression. Conclusions: Time-restricted feeding is an effective and feasible nutritional intervention to improve metabolic health, namely hepatic steatosis, in a model of childhood obesity. These data open new avenues for future safe and efficient chrono-nutritional interventions aimed to improve metabolic health in children with overweight/obesity.

Cross-sectional associations between adipose tissue depots and areal bone mineral density in the UK Biobank imaging study.

Assess the relationship between direct measures of adiposity (total body fat mass, visceral adipose tissue, and abdominal subcutaneous adipose tissue) with the whole body and clinically relevant bone sites of the lumbar spine, and femoral neck areal bone mineral density (aBMD) in men and women. This cross-sectional analysis was conducted utilizing de-identified data from the UK Biobank on participants (n = 3674) with available dual-energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI) data. Sex-stratified multiple linear regression was used to assess the relationship between adiposity measures and aBMD outcomes, controlling for age, race, total body lean mass (DXA), height, BMI class, physical activity, smoking, menopausal status (women), and hormone use (women). In men, significant interactions were observed between measures of adiposity and BMI on aBMD for the whole body and lumbar spine. Interactions indicated a positive relationship between adiposity and aBMD in men classified as normal weight, but an inverse relationship in men with elevated BMI. In women, significant interactions between adiposity measures and menopausal status were observed primarily for the whole body and femoral neck aBMD bone outcomes which indicated a negative relationship between adiposity and aBMD in premenopausal women, but a positive relationship in postmenopausal women. Total body adiposity, abdominal subcutaneous adipose tissue, and visceral adipose tissue were all significantly associated with aBMD in both men and women. The strength and direction of association were dependent on sex, BMI classification, and menopausal status (women).

Multicomponent density models for body composition: Review of the dual energy X-ray absorptiometry volume approach.

Accurate and precise body composition estimates, notably of total body adiposity, are a vital component of in vivo physiology and metabolic studies. The reference against which other body composition approaches are usually validated or calibrated is the family of methods referred to as multicomponent "body density" models. These models quantify three to six components by combining measurements of body mass, body volume, total body water, and osseous mineral mass. Body mass is measured with calibrated scales, volume with underwater weighing or air-displacement plethysmography, total body water with isotope dilution, and osseous mineral mass by dual-energy X-ray absorptiometry. Body density is then calculated for use in model as body mass/volume. Studies over the past decade introduced a new approach to quantifying body volume that relies on dual-energy X-ray absorptiometry measurements, an advance that simplifies multicomponent density model development by eliminating the need for underwater weighing or air-displacement plethysmography systems when these technologies are unavailable and makes these methods more accessible to research and clinical programs. This review critically examines these new dual-energy X-ray approaches for quantifying body volume and density, explores their shortcomings, suggests alternative derivation approaches, and introduces ideas for potential future research studies.

Ethnic Differences in the Association Between Body Mass Index and Type 2 Diabetes Risk: A Meta-Analysis of Prospective Cohort Studies

ObjectivesThe association between body mass index (BMI) and total body adiposity differs across ethnic groups. For instance, South Asians (SA) and East Asians (EA) have lower body fat for a given BMI level than Europeans, while the opposite is true for African-Caribbeans (AC). This suggests that the relationship between BMI and type 2 diabetes (T2D) risk may also vary depending on ethnicity. We conducted a meta-analysis to investigate whether the association between BMI and the risk of T2D differs across ethnic groups. MethodsMEDLINE, EMBASE and Web of Science were searched up to July 2020. We included prospective cohort studies of >2 years, which investigated the association between BMI and T2D incidence among adults of a specified ethnicity. Linear and non-linear dose-response meta-analyses were performed using random effects models, with subgroup analyses by ethnicity. The heterogeneity among studies was estimated using the Cochran Q test and I2 statistic. Study quality was assessed with the Newcastle-Ottawa Scale. Results54 studies were included. Cohorts were stratified into the following ethnic subgroups: AC (N = 67,453), EA (N = 1,012,135), European (N = 206,424), Indigenous (N = 10,533), Latin American (LA) (N = 4,669), SA (N = 9,395), and Southeast Asian (SEA) (N = 51,129). Linear dose-response associations between 1 kg/m2 increase in BMI and T2D were observed for the SEA (RR = 1.26; 95% CI, 1.10, 1.30) and SA (RR = 1.11; 95% CI: 1.04, 1.19) subgroups with no evidence of departure from linearity. Associations departed from linearity for all other subgroups. At a BMI level of 30 kg/m2, the non-linear dose-response curves for each of the other subgroups displayed the following risk ratios; AC: RR = 3.13 (95% CI, 1.95, 5.02), EA: RR = 2.39 (95% CI, 1.96, 2.92), European: RR = 7.41 (95% CI, 3.88, 14.18), Indigenous: RR = 8.15 (95% CI, 6.07; 10.95), and LA: RR = 12.82 (95% CI, 5.50, 29.92). For all subgroups, there was a high degree of interstudy heterogeneity (I2 > 75%). ConclusionsOur findings indicated that the association between BMI and the risk of T2D differs across ethnic groups, suggesting that ethnic-specific BMI cut-offs could be helpful in identifying cardiometabolic risk profiles across different populations. Funding SourcesCanadian Institutes for Health Research.