Changes In Body Fat Research Articles

Evaluating the summer landscapes of predation risk and forage quality for elk (Cervus canadensis).

The recovery of carnivore populations in North American has consequences for trophic interactions and population dynamics of prey. In addition to direct effects on prey populations through killing, predators can influence prey behavior by imposing the risk of predation. The mechanisms through which patterns of space use by predators are linked to behavioral response by prey and nonconsumptive effects on prey population dynamics are poorly understood. Our goal was to characterize population‐ and individual‐level patterns of resource selection by elk (Cervus canadensis) in response to risk of wolves (Canis lupus) and mountain lions (Puma concolor) and evaluate potential nonconsumptive effects of these behavioral patterns. We tested the hypothesis that individual elk risk‐avoidance behavior during summer would result in exposure to lower‐quality forage and reduced body fat and pregnancy rates. First, we evaluated individuals' second‐order and third‐order resource selection with a used‐available sampling design. At the population level, we found evidence for a positive relationship between second‐ and third‐order selection and forage, and an interaction between forage quality and mountain lion risk such that the relative probability of use at low mountain lion risk increased with forage quality but decreased at high risk at both orders of selection. We found no evidence of a population‐level trade‐off between forage quality and wolf risk. However, we found substantial among‐individual heterogeneity in resource selection patterns such that population‐level patterns were potentially misleading. We found no evidence that the diversity of individual resource selection patterns varied predictably with available resources, or that patterns of individual risk‐related resource selection translated into biologically meaningful changes in body fat or pregnancy rates. Our work highlights the importance of evaluating individual responses to predation risk and predator hunting technique when assessing responses to predators and suggests nonconsumptive effects are not operating at a population scale in this system.

Changes in physical activity and adiposity with all-cause, cardiovascular disease, and cancer mortality

BackgroundThe relationship between joint changes in physical activity and adiposity with mortality is not well understood. We examined the association of changes in these two established risk factors with all-cause (ACM), cardiovascular disease (CVD), and cancer mortality.MethodsWe used longitudinal data from Taiwan’s MJ Cohort, comprising 116,228 general population adults recruited from 1998-2013 with repeated measures 4.6 y (2.5) apart and followed up for mortality for 11.9 y (3.5). Physical activity, body mass index (BMI), waist circumference (WC), and body fat percentage (BF%) groups and changes were based on public health and clinical guidelines.ResultsCompared to stable-insufficient physical activity, increasing physical activity from any baseline level was associated with lower ACM (HR [95%CI]): 0.85 [0.74, 0.96]) and CVD mortality (0.72 [0.55, 0.93]) risk. This was approximately equal to meeting physical activity guidelines at both timepoints (eg: 0.71 [0.58, 0.88] for CVD mortality). Compared to stable-overweight/moderate adiposity, decreasing adiposity level attenuated but did not offset mortality risk for all three outcomes (eg: BMI = 0.95 [0.76, 1.16] for CVD mortality). Only maintaining a healthy adiposity level at both timepoints offset mortality risk (BMI = 0.75 [0.61, 0.89]) for CVD mortality). In the joint changes analyses, lower mortality risk was a consequence of increases in physical activity across adiposity change groups (eg: WC decrease = 0.57 [0.48, 0.67]; WC stability = 0.73 [0.66, 0.80], WC increase = 0.83 [0.72, 0.97] for ACM). Decreasing adiposity attenuated the negative associations of decreased physical activity (BF% = 1.13 [0.95, 1.35] for ACM).ConclusionsWe found a lower risk for ACM, CVD, and cancer mortality from increasing physical activity and an attenuation from decreasing adiposity regardless of baseline levels. The beneficial associations of joint changes were primarily driven by physical activity, suggesting lower mortality risk may be more immediate through physical activity improvements compared to adiposity improvements alone.

Weight Gain and Body Composition Changes during the Transition of Thyroid Function in Patients with Graves' Disease Undergoing Radioiodine Treatment.

Objective This study aimed at investigating the dynamic changes in the body weight and body composition in a group of patients with Graves' disease undergoing radioiodine therapy. Methods Seventeen patients with Graves' disease undergoing 131I treatment and forty-three euthyroid controls were recruited. Body weight, BMI, and body composition via bioelectrical impedance were measured for the participants at baseline, hypothyroid stage, and euthyroid stage. Results Body weight increased significantly during the transition from hyperthyroidism to euthyroidism. However, there were no significant changes in body fat %, lean mass %, and bone mineral %. The body weight of 9 patients at the euthyroid stage exceeded their premorbid weight, while the remaining 8 patients' weight did not exceed the premorbid weight. In the group with excessive weight gain, both body fat and lean mass increased significantly. However, in the group without excessive weight gain, only lean mass increased significantly. The patients with excessive weight gain had significantly higher body fat %, while lower lean mass % compared to patients without excessive weight gain at baseline and at the euthyroid stage. Moreover, body fat % of patients with excessive weight gain was significantly higher than that of controls, while lean mass % was significantly lower than that of controls. There was no difference of body fat % and lean mass % between patients without excessive weight gain and controls. Conclusion 131I treatment caused significant weight gain in patients with Graves' disease. An undesirable body composition at presentation may be a risk factor for excessive weight gain after hyperthyroidism treatment.

Serum Hormone Concentrations and Body Composition in Brazilian Air Force Cadets During Rainforest Survival Training.

Physiological adaptations in military jungle survival training have not yet been studied. Knowledge about the relationship between the insulin-like growth factor type I (IGF-I)/insulin-like growth factor binding protein type 3 (IGFBP-3) system and survival activities in a jungle environment can improve readiness and prepare Brazilian Air Force cadets for this kind of battlefield. Our goal was to assess changes in body composition and serum concentrations of the IGF-I/IGFBP-3 system in Brazilian Air Force cadets during five-day Amazon rainforest survival training and whether differences in sex influence these variations. In the five-day survival training, variations in body composition and serum levels of IGF-I and IGFBP-3 were observed. The sample consisted of 14 male cadets (21.71 ± 1.64 years) and 6 female cadets (22.00 ± 1.41 years). Changes were assessed before and immediately after the survival training. The male cadets' body mass (pre: 73.89 ± 8.79 kg; post: 69.57 ± 8.44 kg), body fat (pre: 11.43 ± 4.15%; post: 10.16 ± 4.19%), IGF-I serum concentrations (pre: 252 ± 72 ng/mL; post: 140 ± 42 ng/mL), and IGFBP-3 serum concentrations (pre: 4.90 ± 0.67 ng/mL; post: 4.22 ± 0.73 ng/mL) were significantly reduced (P < .01). In the female cadets, the mean body mass values (pre: 60.98 ± 8.82 kg; post: 57.91 ± 9.01 kg), body fat (pre: 19.20 ± 5.03%; post: 17.19 ± 4.77%), and IGF-I serum concentrations (pre: 202 ± 50 ng/mL; post: 108 ± 29 ng/mL) also decreased significantly (P < .01) after survival training. Finally, the cadet's sex does not affect the variations of IGF-I (P = .46) and IGFBP-3 (P = .205) serum concentrations. These findings all suggest that changes in body mass and body fat, as well as variations in the IGF-I/IGFBP-3 system, corroborate the need for military readiness preparation. Equivalent changes in both sexes indicate probable equal recovery intervals after survival training.

Heterogeneity in risk‐sensitive allocation of somatic reserves in a long‐lived mammal

AbstractFood quality and availability, when combined with energetic demands in seasonal environments, shape resource acquisition and allocation by animals and hold consequences for life‐history strategies. In long‐lived species with extensive maternal care, regulation of somatic reserves of energy and protein can occur in a risk‐sensitive manner, wherein resources are preferentially allocated to support survival at the cost of investment in reproduction. We investigated how Rocky Mountain bighorn sheep (Ovis canadensis), an alpine mammal in a highly seasonal environment, allocates somatic reserves across seasons. In accordance with the hypothesis of risk‐sensitive resource allocation, we expected accretion and catabolism of somatic reserves to be regulated relative to preseason nutritional state, reproductive state, and variation among populations in accordance with local environmental conditions. To test that hypothesis, we monitored seasonal changes in percent ingesta‐free body fat (IFBFat) and ingesta‐free, fat‐free body mass (IFFFBMass) in three populations of bighorn sheep in northwest Wyoming between 2015 and 2019 through repeated captures of female sheep in December and March of each year in a longitudinal study design. Regulation of somatic reserves was risk‐sensitive and varied relative to the amount of somatic reserves an animal had at the beginning of the season. Regulation of fat reserves was sensitive to reproductive state and differed by population, particularly over the summer. In one population with low rates of recruitment of young, sheep that recruited offspring lost fat over the summer in contrast to the other two populations where sheep that recruited gained fat. And yet, all populations exhibited similar changes in fat catabolism and risk sensitivity over winter. The magnitude of body fat and mass change across seasons may be indicative of sufficiency of seasonal ranges to meet energetic demands of survival and reproduction. Risk‐sensitive allocation of resources was pervasive, suggesting nutritional underpinnings are foundational to behavior, vital rates, and, ultimately, population dynamics. For species living in alpine environments, risk‐sensitive resource allocation may be essential to balance investment in reproduction with ensuring survival.

A height-weight formula to measure body fat in childhood obesity

BackgroundThe assessment of body composition is central in diagnosis and treatment of paediatric obesity, but a criterion method is not feasible in clinical practice. Even the use of bioelectrical impedance analysis (BIA) is limited in children. Body mass index (BMI) Z-score is frequently used as a proxy index of body composition, but it does not discriminate between fat mass and fat-free mass. We aimed to assess the extent to which fat mass and percentage of body fat estimated by a height-weight equation agreed with a BIA equation in youths with obesity from South Italy. Furthermore, we investigated the correlation between BMI Z-score and fat mass or percentage of body mass estimated by these two models.MethodsOne-hundred-seventy-four youths with obesity (52.3% males, mean age 10.8 ± 1.9) were enrolled in this cross-sectional study. Fat mass and percentage of body fat were calculated according to a height-weight based prediction model and to a BIA prediction model.ResultsAccording to Bland–Altman statistics, mean differences were relatively small for both fat mass (+ 0.65 kg) and percentage of body fat (+ 1.27%) with an overestimation at lower mean values; the majority of values fell within the limits of agreement. BMI Z-score was significantly associated with both fat mass and percentage of body fat, regardless of the method, but the strength of correlation was higher when the height-weight equation was considered (r = 0.82; p < 0.001).ConclusionsThis formula may serve as surrogate for body fat estimation when instrumental tools are not available. Dealing with changes of body fat instead of BMI Z-score may help children and parents to focus on diet for health.

Anti-Obesity Effect of Porcine Collagen Peptide in 3T3-L1 Adipocytes and High-Fat Diet-Fed Mice by Regulating Adipogenesis.

Obesity is one of the most common diseases caused by an imbalance in the intake and expenditure of energy, and it is associated with various metabolic complications. This study aimed at investigating the anti-obesity effects and mechanisms of porcine collagen peptide (PCP) using 3T3-L1 preadipocytes and high-fat diet (HFD)-fed mice. The PCP treatment significantly inhibited the adipocyte differentiation and attenuated the mRNA expression of transcription factors (CCAAT/enhancer-binding protein alpha [C/EBPα] and peroxisome proliferator-activated receptor gamma [PPARγ]) and the lipogenic gene (fatty acid synthase [FAS]) expression in 3T3-L1 preadipocytes. In the in vivo study, HFD-fed mice were fed low- (1.5 g/kg body weight/day) and high- (4.5 g/kg body weight/day) PCP for 12 weeks and compared with the normal diet-fed group and HFD-fed control group. The PCP-fed groups showed significantly lower body weight gain, white fat weight gain, serum triglycerides, and adipocyte size compared with the HFD-fed group. The changes in body fat were associated with the upregulation of adiponectin and the downregulation of leptin, C/EBPα, PPARγ, and FAS. These results suggest that PCP has the potential to reduce obesity by suppressing adipogenesis and could be applied as a functional food material.

Association between intake of marine fat and adiposity development among children ages 2 to 6 y: Substitution analyses from the Healthy Start intervention study

ObjectivesA few previous studies have described a potential role of Ω-3 long-chain polyunsaturated fatty acids from marine animals in obesity in children, but the results are conflicting. The objectives of this study were to examine if intake of marine fat was related to less gain in body mass index (BMI) and body fat (BF) over a 15-mo period among Danish children age 2 to 6 y, and if potential associations depended on which types of fatty acids were replaced. MethodsA total of 355 children age 2 to 6 y were included in the study. Weight, height, and BF percentage (BF%) assessed by bioimpedance were measured by trained research personnel. Multivariable linear regression models were used to investigate associations between marine fat intake and changes in BMI or BF% over the subsequent 15 mo. To investigate substitution effects, we constructed regression models that included marine fat and all other energy yielding dietary components, except for the nutrient to be substituted for either all fats or specific subgroups (saturated, monounsaturated, or other polyunsaturated fatty acids). ResultsNo significant associations were observed between intake of marine fat and development in BMI or BF% in any of the analyses, either with or without specified substitutions. Furthermore, the results were independent on whether intake was expressed in g/d or percentage of energy, and were not modified by age or BMI status. ConclusionsThis study suggests that marine fat intake and fat composition in a diet may have little or no effect on weight and adiposity development among preschool-aged children.

Breath analyzer for personalized monitoring of exercise-induced metabolic fat burning

Obesity increases the risk of chronic diseases, such as type 2 diabetes mellitus, dyslipidemia, and cardiovascular diseases. Simple anthropometric measurements have time limitations in reflecting short-term weight and body fat changes. Thus, for detecting, losing or maintaining weight in short term, it is desirable to develop portable/compact devices to monitor exercise-induced fat burn in real time. Exhaled breath acetone and blood-borne β-hydroxybutyric acid (BOHB) are both correlated biomarkers of the metabolic fat burning process that takes place in the liver, predominantly post-exercise. Here, we have fabricated a compact breath analyzer for convenient, noninvasive and personalized estimation of fat burning in real time in a highly automated manner. The analyzer collects end-tidal breath in a standardized, user-friendly manner and it is equipped with an array of four low-power MEMS sensors for enhanced accuracy; this device presents a combination of required and desirable design features in modern portable/compact breath analyzers. We analyzed the exhaled breath (with our analyzer) and the blood samples (for BOHB) in 20 participants after exercise; we estimated the values of BOHB, as indication of the fat burn, resulting in Pearson coefficient r between the actual and predicted BOHB of 0.8. The estimation uses the responses from the sensor array in our analyzer and demographic and anthropometric information from the participants as inputs to a machine learning algorithm. The system and approach herein may help guide regular exercise for weight loss and its maintenance based on individuals’ own metabolic changes.

1040-P: Associations between Sleep Characteristics and Changes in Body Weight and Fat from 6–8 Weeks to 6 Months Postpartum in Black and White Women

The literature indicates Black women tend to lose less weight after pregnancy than White women. Sleep duration and quality have been associated with body weight and fat in other populations. Thus, the purpose of this study was to determine whether associations between sleep characteristics and changes in body weight and fat during postpartum in Black and White women were different. Black (n=29) and White (n=76) women who gave birth to a singleton infant at ≥37 weeks gestation participated in the study. They were instructed to wear an actigraph monitor to measure sleep at 6-8 weeks, 4 months, and 6 months postpartum for 7 days, and to complete a sleep diary. Total sleep time, wake time after sleep onset, and the sleep fragmentation index (an estimate of sleep disruption) were determined. Percent body fat (by dual-energy X-ray absorptiometry) and body weight were determined at 6-8 weeks and 6 months postpartum. A race by sleep characteristic interaction term was included in linear regression models to determine whether Black and White women had different bivariate correlations between sleep characteristics at each time point and changes in body weight and percent body fat from 6-8 weeks to 6 months. Results indicate significant interaction terms of sleep fragmentation index at 6-8 weeks and race for both weight and fat change (p=0.006, and 0.028, respectively) . Specifically, in Black women, sleep fragmentation index at 6-8 weeks were negatively associated with changes in percent body fat and weight (p= 0.027 and 0.032, respectively) , so that greater sleep disruption at 6-8 weeks was associated with less reduction in weight and percent body fat. In White women, these significant associations were absent. In conclusion, these results suggest different contributions of sleep characteristics to postpartum weight and fat changes in Black and White women. The reasons for the differences need further investigation. Disclosure X.Wang: None. E.Kishman: None. Funding National Institutes of Health (R21MD012740)

Recreational Soccer, Body Composition and Cardiometabolic Health: A Training-Intervention Study in Healthy Adolescents

Recreational soccer (RS) is widely used for adolescents as a physical activity method. However, its impact on physical fitness, body composition and metabolic health in adolescents has not been extensively examined yet. The purpose of the present study was to examine the contribution of changes in body fatness and aerobic capacity to modifications in circulating blood lipids profile, following 8-weeks of RS in healthy youth. Fifty-three healthy male adolescents were separated in three groups: one performed RS (3 times x 60 min/week); the other two were served as control groups [soccer-specific training (SST) one and inactive one]. Physical fitness, body composition and blood lipids and glucose responses were evaluated before and after 8-weeks of exercise intervention. Post-intervention body weight and body fat percentage (BF%) were lowered, while physical fitness was improved (p < 0.05) in SST group only. High density lipoprotein cholesterol (HDL-C) was higher (n² = .378) and total cholesterol (TC)/HDL-C ratio was lower (n² = .195) in the SST group relative to RS and inactive groups (p < 0.05). In conclusion, although RS may improve aerobic capacity, relative to inactive control group, it does not influence body fatness and cardiometabolic health in adolescents. Consequently, RS may not secure health benefit during the crucial transition period from adolescence to adulthood.

The Effect of a Mediterranean Diet With or Without Calorie Restriction on Cognition, Lifestyle, and Metabolic Health of Obese, Predominately Non-Hispanic Black Older Adults

ObjectivesTo compare the effect of a Mediterranean Diet with (Med-WL) or without caloric restriction (Med-A) for intentional weight loss (IWL) versus a typical diet control (TDC) on cognition, lifestyle and cardiometabolic health.MethodsA randomized clinical trial of obese, predominately non-Hispanic black, older adults was conducted between June 2017 and December 2020 at community sites in Chicago, Illinois. Participants (n = 185) were randomized (2:2:1) to 1 of 3 groups for 8-months: Med-WL, Med-A, or TDC. The primary outcome was change from baseline to post-intervention in three cognitive composite scores: attention, information & processing; executive function; and learning, memory & recognition. Secondary outcomes included changes in MedDiet adherence, physical activity, body weight, total and regional body fat, blood pressure, fasting blood lipids, glucose, insulin and C-reactive protein (CRP).ResultsParticipants were 85.9% female with a mean (SD) age of 66.3 (6.1) years, and retention was similar across arms (85.3% Med-WL, 87.7% Med-A, 94.6% TDC, p = 0.36). The MedDiet interventions did not affect cognitive composite scores. MedDiet adherence improved significantly more in Med-WL (adjusted mean [95% CI] score change, +6.3 [4.9 to 7.6] points) and Med-A (+4.8 [3.4 to 6.2] points) relative to TDC (+0.6 [−1.3 to 2.4] points, p < 0.05). Weight loss was significantly greater in Med-WL (adjusted mean [95% CI]: −4.6 [(-5.6 to −3.5] kg) than in Med-A (-2.6 [−3.7 to −1.5] kg, p < 0.05) and TDC (−0.6 [−2.1 to 0.8] kg, p < 0.05). Reduction in central body fat was significantly greater in the MedDiet arms (adjusted mean change [95% CI], Med-WL: −147 [−235 to −59] gm; Med-A: −162 [−248 to −76] gm) than in TDC (+91 [−18 to 200] gm, p < 0.05). For cardiometabolic health, only fasting insulin changed significantly in Med-WL (adjusted mean change [95% CI]: −2.2 [−3.2 to −1.2] uIU/mL) relative to Med-A (−0.6 [−1.6 to 0.4] uIU/mL, p < 0.05) and TDC (−0.5 [−1.8 to 0.8] uIU/mL, p < 0.05).ConclusionsAn 8-month MedDiet lifestyle intervention with or without caloric restriction for IWL did not produce superior effects on cognitive function compared to a TDC, but it did produce significant effects on diet quality, total body weight and central body fat.Funding SourcesNational Heart, Lung And Blood Institute; National Cancer Institute; National Institute On Minority Health And Health Disparities.

Association Between Longitudinal Changes in Body Mass Index (BMI) and Body Fat With Cardiometabolic Risk Factors in Indian Children and Adolescents

ObjectivesTo evaluate the associations between longitudinal changes in body mass index (BMI) and body fat mass (FM%) with cardiometabolic risk factors in school-aged children and adolescents from South India.MethodsThis prospective school-based study comprised 4,289 children and adolescents (44.2% male) aged 5–17y participating in the PEACH-II and III studies in Bengaluru, India. Anthropometry and FM% (BOD POD, Cosmed; 5.2.0) were measured twice with a median age gap of 2.8y. Waist circumference (WC), systolic/diastolic blood pressure, HbA1c, and lipid profile were measured at endline. BMI-for-age z-scores were calculated using the World Health Organization Child Growth Standards, and were used to define overweight (≥+1 SD to < +2 SD) and obesity (≥+2 SD). Linear regression was used to examine the associations between longitudinal changes in BMI-for-age z-scores and FM% with cardiometabolic risk factors, after adjusting for parental BMI, socioeconomic status, age of menarche, inflammation (c-reactive protein), physical activity and night sleep duration.ResultsThe prevalence of overweight/obesity and mean FM% increased from 15.2% to 20.5%, and 19.5% to 21.7%, respectively during follow-up. Overall, 43.8% and 15.5% of the participants had high triglycerides (TG, ≥200 mg/dL), and elevated HbA1C (≥5.7%), while 40.9% had low HDL (< 40 mg/dL); a total of 69.1% of participants had ≥ 1 abnormal biomarker(s). Increment in BMI for-age z-score of 1SD overtime was significantly associated with higher WC (β: 2.9, [SE:0.20] cm), TG (8.4, [1.3] mg/dL), HbA1c (0.17, [0.06] %), total cholesterol (1.6, [0.56] mg/dL), and lower HDL (−1.3, [0.26] mg/dL). Longitudinal increment in FM% was associated with higher WC (0.3, [0.03] cm), TG (1.2, [0.15] mg/dL) and total cholesterol (0.4, [0.1] mg/dL).ConclusionsThe burden of overweight/obesity and FM% substantially increased in this population of South Indian children and adolescents overtime, and were associated with cardiometabolic risk factors. Regular monitoring of BMI and body composition can help to identify children at risk of developing cardiovascular diseases. Appropriate dietary and lifestyle interventions for children at risk are needed in India, where chronic diseases and associated deaths are increasing at alarming rate in young and older adults.Funding SourcesFunded by Indian Council of Medical Research.

Problems undermining the health-related quality of life of people living with HIV in Spain: a qualitative study to inform the development of a novel clinic screening tool

BackgroundIn settings with high antiretroviral therapy coverage, numerous health-related issues continue to undermine the health and health-related quality of life (HRQoL) of people living with HIV (PLHIV). As part of a larger study to develop and validate a new patient-reported outcome measure for use in HIV clinical care in Spain, we sought to identify the most burdensome health-related issues experienced by PLHIV in order to determine which issues should be addressed in the new instrument.MethodsWe conducted a literature review and a qualitative study based on four focus group discussions (FGDs) with key informants in Spain. Participants were selected via purposive sampling. Two FGDs convened 16 expert HIV service providers, and two convened 15 PLHIV with diverse epidemiological profiles. FGDs followed semi-structured interview scripts and incorporated an exercise to prioritise the most critical health-related issues among those named in the discussions. Content analysis was conducted using MAXQDA 12.ResultsThe analysis of FGD data identified several broad categories of issues that were perceived to negatively affect PLHIV. The most frequently named issues fell within the categories of social problems; physical symptoms; psychological problems; and sexuality-related problems. Regarding social problems, stigma/discrimination was by far the issue raised the most frequently. In the prioritisation exercise, stigma/discrimination was also ranked as the most burdensome issue by both service providers and PLHIV. Within the physical symptoms category, the issues named most frequently were sleep-related problems, fatigue, physical pain and body fat changes. Regarding psychological problems, FGD participants most commonly spoke of emotional distress in general terms, and also called attention to depression and anxiety. In the prioritisation exercise, both service providers and PLHIV ranked psychological well-being as the second-most important issue following stigma. Sexuality-related problems that were reported included sexually transmitted infections, hormonal problems, lack of libido, and general sexual dissatisfaction.ConclusionsPLHIV are negatively affected by a wide range of health-related issues. HIV-related stigma and psychological well-being remain major challenges. Identifying and addressing these and other issues in routine clinical care supports healthy aging and may ultimately contribute to better health and HRQoL outcomes in this population.

0222 A shift in the circadian timing of calories and an increase in sleep variability are associated with changes in cardiometabolic health in a real-world setting

Abstract Introduction Obesity and cardiovascular disease are commonplace in industrialized societies, particularly in nightshift workers. To investigate whether a shift in the circadian timing of energy intake or an increase in sleep variability may be mechanisms for adverse cardiometabolic health, we leveraged a natural experiment that occurs in newly-hired bus operators as they transition from a regularly-timed training schedule into an erratically-timed (i.e., early-morning or late evening) work schedule. Methods Twenty-one newly-hired bus operators (8 females, 37.1y±6.4y [mean±SD]) were studied in an ~90-day protocol. During dayshift training (i.e., baseline), participants underwent a battery of in-laboratory cardiometabolic health assessments (i.e., blood pressure [BP], blood draw, body fat percentage), and a salivary dim-light melatonin assessment (DLMO). Participants then completed daily sleep-wake diaries and recorded all food and beverages consumed using a photographic time-stamped phone application (MealLoggerTM) for one week. These measurements were repeated ~30 and ~90 days after starting their new work schedules operating a bus. Caloric intake was determined via registered dieticians and DLMO was defined using a 3pg/ml threshold. As indices of caloric timing we used the time when participants consumed 50% of daily calories (caloric midpoint), and the percent of daily calories consumed within 4h of DLMO. Sleep variability was measured as the standard deviation of sleep onset timing. Associations were calculated using Pearson’s correlations. Results After 90-days of working, caloric midpoint occurred 2h later than baseline (16:22±02:41 vs. 14:24±02:07; p&amp;lt;0.01). This shift in timing was correlated with increases in systolic BP (r2=0.28; p=0.02) and low-density lipoprotein cholesterol (r2=0.28; p=0.03). An increase in sleep variability at 90-days was also positively correlated with systolic BP (r2=0.31; p=0.02). The change in percent of calories consumed within 4h of DLMO was positively correlated with change in percentage body fat (r2=0.27; p=0.03). Last, there was no significant correlation between the change in daily calories consumed and body fat percentage (p=0.24). Conclusion Changes in the timing of caloric intake relative to DLMO, along with increases in sleep variability, may be mechanisms for increased cardiometabolic risk. These behaviors are potential targets for intervention to improve cardiometabolic health. Support (If Any) R01HL105495, K01HL146992

Gut microbiota predicts body fat change following a low-energy diet: a PREVIEW intervention study

BackgroundLow-energy diets (LEDs) comprise commercially formulated food products that provide between 800 and 1200 kcal/day (3.3–5 MJ/day) to aid body weight loss. Recent small-scale studies suggest that LEDs are associated with marked changes in the gut microbiota that may modify the effect of the LED on host metabolism and weight loss. We investigated how the gut microbiota changed during 8 weeks of total meal replacement LED and determined their associations with host response in a sub-analysis of 211 overweight adults with pre-diabetes participating in the large multicentre PREVIEW (PREVention of diabetes through lifestyle intervention and population studies In Europe and around the World) clinical trial.MethodsMicrobial community composition was analysed by Illumina sequencing of the hypervariable V3-V4 regions of the 16S ribosomal RNA (rRNA) gene. Butyrate production capacity was estimated by qPCR targeting the butyryl-CoA:acetate CoA-transferase gene. Bioinformatics and statistical analyses, such as comparison of alpha and beta diversity measures, correlative and differential abundances analysis, were undertaken on the 16S rRNA gene sequences of 211 paired (pre- and post-LED) samples as well as their integration with the clinical, biomedical and dietary datasets for predictive modelling.ResultsThe overall composition of the gut microbiota changed markedly and consistently from pre- to post-LED (P = 0.001), along with increased richness and diversity (both P < 0.001). Following the intervention, the relative abundance of several genera previously associated with metabolic improvements (e.g., Akkermansia and Christensenellaceae R-7 group) was significantly increased (P < 0.001), while flagellated Pseudobutyrivibrio, acetogenic Blautia and Bifidobacterium spp. were decreased (all P < 0.001). Butyrate production capacity was reduced (P < 0.001). The changes in microbiota composition and predicted functions were significantly associated with body weight loss (P < 0.05). Baseline gut microbiota features were able to explain ~25% of variation in total body fat change (post–pre-LED).ConclusionsThe gut microbiota and individual taxa were significantly influenced by the LED intervention and correlated with changes in total body fat and body weight in individuals with overweight and pre-diabetes. Despite inter-individual variation, the baseline gut microbiota was a strong predictor of total body fat change during the energy restriction period.Trial registrationThe PREVIEW trial was prospectively registered at ClinicalTrials.gov (NCT01777893) on January 29, 2013.

Modeling Analysis of the Relationship between Adolescent Aerobic Exercise and Obesity Reduction Based on Deep Learning

In order to explore the modeling analysis of the relationship between adolescent aerobic exercise and obesity reduction, the relationship modeling method of deep learning algorithm is proposed. This study integrates deep learning algorithms and first uses the changes in body shape, weight, BMI index, body fat, body circumference, and other indicators of adolescent obese before and after aerobic exercise as the initial pheromone distribution matrix and introduces random evolution factor and evolutionary drift threshold to establish the objective function of aerobic exercise to reduce adolescent obesity. It also explains the constraint conditions that aerobic exercise has to meet in the reduction of adolescent obesity and introduces particle algorithm to establish a model of optimal aerobic exercise to reduce adolescent obesity. The simulation results show that, under the same number of experiments, the advantages of this method are more obvious. On the overall level, the average modeling error of this method is about 0.053%, while the average of the traditional method is about 0.186%, indicating that the method can reduce the error control within a reasonable range. It proves that deep learning can effectively reflect the modeling analysis of the relationship between adolescent aerobic exercise and obesity reduction.

Abstract #1185212: Obesity Management via Telemedicine Shared Medical Appointments

Obesity as a chronic disease has reached pandemic proportions. The prevalence of obesity between 2017-2018 was 42.4%, and the national healthcare cost on obesity amounts to $149.4 billion annually. Current strategies for weight management are limited to lifestyle changes, anti-obesity medications (AOM), and bariatric surgeries. However all of these treatment options are grossly underutilized with weight loss counseling occurring in fewer than 5.8% of primary care visits and only 0.8% of eligible patients receive AOM’s. Shared medical appointments (SMA) have emerged as a potential option to address the obesity pandemic, allowing patients to convene with a team of multidisciplinary providers in a group setting. There are few studies on the use of SMA’s in obesity management and even fewer studies assessing the efficacy of telemedicine SMA’s. Here we present a study examining the weight loss impact of telemedicine SMA’s through Program for Reducing Obesity (PRO), our institutional weight management clinic. Patients age ≥18 years with body mass index (BMI) ≥30 kg/m2 were referred from the community to PRO at the UCLA Thousand Oaks clinic. In addition to individual clinic visits, patients participated in weekly SMA group classes for counseling and education via video conference led by an obesity medicine board certified endocrinologist and a registered dietician. Enrollment period spanned from May 2020 to May 2021. Primary outcomes were change in body weight and percent body fat at 3 months and 6 months. Secondary outcome includes percentage of patients who achieved 5% weight loss. Thirty-two patients (mean age 62.1 years, 78% women, mean weight 97.6kg, mean BMI 35.6 kg kg/m2) were analyzed, with 27 patients completing at least 4 SMA sessions. Patients achieved on average a weight loss of 3.5% at 3 months and 4.9% at 6 months. By 6 months, 34.4% of the patients reached weight loss of ≥5%. Patients also achieved on average a 0.7% decrease in body fat at 3 months and 2.8% at 6 months. Overall 18.8% of participants were taking AOM by 6 months. Our study demonstrates that telemedicine SMA’s can be an efficient and effective approach to obesity management.

Characterizing the Effects of High Fat and High Carbohydrate Diets on Feeding Behavior and Energy Expenditure in Mice

ObjectiveWe sought to characterize how different compositions of the diet can alter feeding behavior and energy expenditure in mice, ultimately driven by changes in sympathetic activation and thermogenesis.HypothesisMice on a high fat diet (HFD) will consume more calories/day compared to high carbohydrate diet (HCD) and standard chow fed mice. Mice on HFD will have decreased expression of UCP1 in both brown and white adipose tissue. There will be decreased expression for several lipolytic enzymes in the white adipose of HFD mice.MethodsA total of 21 mice were divided into three ad libitum fed diet groups: HFD, HCD, and standard chow. Each group was fed their respective diet for 7 weeks. Changes in weight and percent body fat were recorded by NMR. At week 5, glucose tolerance tests were performed on all mice. Both a 24‐hour heat production and respiratory exchange ratio were collected on each group using a metabolic cage system. Mice were sacrificed at the conclusion of week 7 and organs were collected for molecular analysis.ResultsWe show that mice on both ad libitum HFD and HCD consume significantly more calories/day when compared to standard chow. Both HFD and HCD fed mice have a significantly increased body weight and percent body fat when compared to standard chow; however, the HFD mice had a far greater increase in weight compared to HCD fed mice despite no difference in calorie consumption. Mice on a HFD had a lower 24‐hour average heat production per body mass when compared to standard chow and HCD mice and a significantly impaired glucose tolerance test. Furthermore, UCP1 mRNA expression is significantly elevated in brown adipose tissue (BAT) of HCD mice compared to that of HFD and standard chow mice. There were no differences in UCP1 expression in subcutaneous or visceral white adipose tissue (WAT) among all groups. There were also no differences in tyrosine hydroxylase (TH) expression in BAT between all mice. Three markers of lipolysis were decreased in visceral WAT of HFD mice compared to HCD and standard chow counterparts.DiscussionMice consumed significantly more calories when fed a HFD or HCD. These mice gain significantly more weight compared to chow with HFD mice gaining weight far more than the HCD group. This major difference in weight gain despite no significant difference in calorie consumption between HFD and HCD suggests differences may be determined by energy expenditure. This evidence is further supported by the fact that HFD fed mice had a significantly lower daily heat production compared to HCD and standard chow mice. We also show that HCD increases thermogenesis in mouse BAT which may be protective against weight gain. Finally, lipolysis signaling seems to be impaired in HFD mice, but no data supports that this is due to differences in sympathetic activation. Further work will include analyzing the same tissues in isocaloric, restricted diet fed mice.

Comparison of Two Diet and Exercise Approaches on Weight Loss and Health Outcomes in Obese Women.

Aim: To compare the efficacy of two popular weight loss approaches on weight loss, body composition, and markers of health in sedentary obese women. Methods: In total, 51 sedentary women (age 34.5 ± 7.7 yrs.; weight 90.0 ± 14.5 kg; BMI 34.0 ± 5.1 kg/m2; 46.5 ± 7.0% fat) were matched and randomized to participate in the Weight Watchers® Momentum™ (WW) or Curves® (CV) Fitness and Weight Management program for 16 weeks. Participants in the WW group (n = 27) were provided a point-based diet program, received weekly progress checks and counseling, and were encouraged to exercise. Participants in the CV group (n = 24) followed a menu-based higher protein/low-fat diet (1200 kcal/d) for 1 week; 1500 kcal/d diet for 3 weeks; and 2000–2500 kcals/d for 2 weeks that was repeated three times (except the last segment) while participating in a supervised circuit-style resistance training program (3 d/wk). A general linear model (GLM) with repeated measures was used to analyze data and are presented as mean changes from baseline (mean [UL, LL]). Results: Supervised CV training resulted in greater amounts of vigorous and total physical activity. After 16 weeks, both groups lost weight (WW −6.1 [−7.8, −4.6], CV −4.9 [−6.2, −3.2] kg, p = 0.264). Participants in the CV group observed greater reductions in fat mass (WW −2.9 [−6.7, −0.2], CV −6.4 [−9.2, −3.6] kg, p = 0.081) and increases in lean mass (WW −2.5 [−4.3, −0.7], CV 1.3 [−0.6, 3.2] kg, p = 0.005) resulting in more favorable changes in percent body fat (WW −1.4 [−4.1, 1.2], CV −4.7 [−7.5, −1.8]%, p = 0.098). Both groups observed improvements in peak aerobic capacity and muscular endurance, although bench press lifting volume was greater in the CV group. Those in the CV group experienced a greater increase in HDLc and reduction in the CHL–HDLc ratio and triglycerides. Conclusion: Both interventions promoted weight loss and improvements in fitness and markers of health. The CV program, which included supervised resistance training and higher protein diet menus, promoted greater fat loss, increases in lean mass, and improvements in percent body fat and blood lipids. Trial Registration: clinicaltrials.gov, #NCT04372771, registered retrospectively 1 May 2020.