Energy balance, body composition, sedentariness and appetite regulation: pathways to obesity

Efficacy and safety of a novel oral hydrogel capsule in adults with overweight or obesity: the pivotal randomized RESET study

OBJECTIVE

The objective of this study was to investigate the efficacy and safety of the Epitomee capsule versus placebo as an adjunct to high-intensity lifestyle intervention in participants with overweight or obesity.

METHODS

The Randomized Evaluation of Efficacy and Safety of the Epitomee Capsule Trial (RESET) was a prospective, double-blind, placebo-controlled pivotal trial in adults with baseline BMI of 27.0 to 40.0 kg/m2. The co-primary endpoints at week 24 were percentage change from baseline in body weight for the Epitomee and placebo groups and proportion of Epitomee-treated patients achieving ≥5% weight loss compared with a 35% threshold. The primary safety endpoint was the incidence of device-related serious adverse events.

RESULTS

A total of 138 participants received Epitomee and 141 received placebo. Mean (SD) change in body weight from baseline was -6.6% (6.5%) with Epitomee and -4.6% ( 4.7%) with placebo; least-squares means were -6.1% (0.6%) and -4.2% (0.6%), respectively (p = 0.0054). Fifty-six percent of Epitomee-treated participants attained ≥5% weight loss from baseline, which was significantly greater than the 35% predefined threshold (p < 0.0001). Twenty-seven percent of Epitomee-treated and eleven percent of placebo-treated participants achieved ≥10% weight loss. Adverse event rates were similar between the groups. No device-related serious adverse events occurred.

CONCLUSIONS

The Epitomee capsule is a safe and efficacious nonpharmacological option for weight management with potential broad application in participants with overweight or obesity.

Does physical activity level and total energy expenditure relate to food intake, appetite, and body composition in healthy older adults? A cross-sectional study

PURPOSE

With ageing, older adults (≥ 65 years) may experience decreased appetite, contributing to declines in body weight and muscle mass, potentially affecting physical capabilities. Physical activity (PA) has been suggested as a potential strategy to enhance appetite in older adults, but evidence supporting this is insufficient. This study aimed to investigate the relationship between PA levels, total energy expenditure (TEE), body composition, energy intake (EI) and appetite in older adults.

METHODS

One hundred and eight healthy older adults (age 70 ± 4 years; BMI 24.3 ± 2.6 kg/m2) were categorised into three groups (low, medium, high) based on accelerometer-measured PA level (AMPA) and TEE from 7-day PA diaries. Body composition was measured using bioelectrical impedance. Energy and nutrient intakes were assessed using 3-day weighed food diaries. Appetite was assessed using the visual analogue scales at 30-min intervals throughout 1 day.

RESULTS

TEE was positively correlated with EI and % muscle mass (p < 0.05), with higher % muscle mass and TEE associated with higher EI. Energy and protein intake were significantly higher in the high TEE group than the low group (p = 0.03, p = 0.01; respectively). No significant differences in energy and macronutrient intake were observed across AMPA groups, and appetite components (hunger, fullness, desire to eat, prospective consumption) did not differ significantly in either the AMPA or TEE groups.

CONCLUSIONS

Higher TEE is associated with higher energy and protein intake, with body composition playing a crucial role. These findings highlight the importance of considering PA, TEE, and body composition in interventions aimed at improving EI in older adults.

CLINICAL TRAIL REGISTRATION

clinicaltrials.gov as NCT05067036. Registered 2 October 2021, https://classic.

CLINICALTRIALS

gov/ct2/show/NCT05067036.

Exploring the physiological factors relating to energy balance in women with polycystic ovary syndrome: a scoping review

Polycystic ovary syndrome (PCOS) occurs in 8%-13% of reproductive-aged women and is associated with reproductive, metabolic, and psychological dysfunction. Overweight and obesity are prevalent and exacerbate the features of PCOS. The aim of this review is to evaluate the extent of evidence examining the physiological factors affecting energy homeostasis, which may impact weight gain, weight loss, and weight maintenance in PCOS, and identify research gaps and recommendations for future research. Literature searches using MEDLINE, EMBASE, PsycInfo, AMED, CINAHL, and Cochrane Central Register of Controlled Trials were conducted up to June 22, 2022. Abstracts, non-English-language articles, and reviews were excluded. A total of n = 78 (n = 55 energy intake and n = 23 energy expenditure) primary research papers were included. Papers with multiple outcomes of interest were counted as separate studies. Energy-intake studies (n = 89) focussed on assessing food, nutrient, or supplements stimuli and were grouped into the outcomes of gastrointestinal appetite hormones (n = 43), adipokines (n = 34), subjective appetite (n = 9), functional brain imaging (n = 3), and neuropeptides (n = 0). Energy-expenditure studies (n = 29) were grouped into total energy expenditure (n = 1), resting energy expenditure (n = 15), meal-induced thermogenesis (n = 3), nutrient oxidation (n = 5), and metabolic flexibility (n = 5). Across both energy-intake and -expenditure papers, 60% of the studies compared outcome responses in women with PCOS with a control group. Results were inconsistent, with 57% reporting no differences and 43% reporting altered responses in PCOS compared with controls, including blunted appetite hormone responses, metabolic inflexibility, and reduced energy expenditure. The authors identified that there is inconsistent, yet preliminary, evidence of possible altered physiological factors, which may impact energy balance and weight management. Further work is needed to act on the identified clinical and research gaps to support women with PCOS and health professionals in informing and achieving realistic weight-management goals for women with PCOS.

SYSTEMATIC REVIEW REGISTRATION

The protocol was prospectively registered on the Open Science Framework on February 16, 2021 (https://osf.io/9jnsm).

Investigating the Effects of Gossypetin on Cardiovascular Function in Diet-Induced Pre-Diabetic Male Sprague Dawley Rats

Gossypetin (GTIN) is a naturally occurring flavonoid recognised for its pharmacological properties. This study examined the effects of GTIN on cardiovascular function in a diet-induced pre-diabetic rat model, which has not been previously studied. Pre-diabetes was induced using a high-fat high-carbohydrate (HFHC) diet supplemented with 15% fructose water for 20 weeks. Thereafter, the pre-diabetic animals were sub-divided into five groups (n = 6), where they were either orally treated with GTIN (15 mg/kg) or metformin (MET) (500 mg/kg), both in the presence and absence of dietary intervention for 12 weeks. The results demonstrated that the pre-diabetic (PD) control group exhibited significantly higher plasma triglyceride, total cholesterol, low-density lipoprotein and very low-density lipoprotein levels, along with decreased high-density lipoprotein (HDL) levels in comparison to the non-pre-diabetic (NPD) group. This was accompanied by significantly higher mean arterial pressure (MAP), body mass index (BMI), waist circumference (WC) and plasma endothelial nitric oxide (eNOS) levels in PD control. Additionally, there were increased heart malondialdehyde levels, reduced heart superoxide dismutase and glutathione peroxidase activity as well as increased plasma interleukin-6, tumour necrosis factor alpha and c-reactive protein levels present in the PD control group. Notably, both GTIN-treated groups showed significantly reduced plasma lipid levels and increased HDL, as well as decreases in MAP, BMI, WC and eNOS levels in comparison to PD control. Additionally, GTIN significantly decreased heart lipid peroxidation, enhanced antioxidant activity and decreased plasma inflammation markers. These findings may suggest that GTIN administration in both the presence and absence of dietary intervention may offer therapeutic potential in ameliorating cardiovascular disturbances associated with the PD state. However, future studies are needed to determine the physiological mechanisms by which GTIN improves cardiovascular function in the PD state.

Relationship between physical activity and abdominal obesity and metabolic markers in postmenopausal women

This study aimed to investigate the impact of physical activity indicators monitored by the POLAR accelerometer on body obesity indicators, metabolic syndrome parameters, and energy metabolism hormones in postmenopausal women. Was included 71 participants from this study program (68.8 ± 4.3 years). We divided participants into LPA and MVPA groups based on their level of moderate to vigorous physical activity per week; Physical activity levels over 7 days were assessed using a POLAR accelerometer, with daily step counts and sedentary time recorded. Measurements included waist circumference, visceral fat volume, body fat percentage, blood pressure, fasting blood glucose, triglyceride levels, HDL cholesterol, and energy metabolism hormone levels (leptin, resistin, adiponectin). The MVPA group displayed lower waist circumference, body fat percentage, abdominal fat, and BMI compared to the LPA group (p < 0.05). A significant negative correlation was observed between daily step count and obesity indicators, including waist circumference (r = -0.301), body fat percentage (r = -0.295), abdominal fat (r = -0.318), and BMI (r = -0.238). Conversely, sedentary time showed a positive correlation with obesity indicators such as waist circumference (r = 0.258), body fat percentage (r = 0.239), and abdominal fat (r = 0.244). Moreover, daily step count exhibited a significant negative correlation with leptin levels (r = -0.245), while sedentary time was positively correlated with the energy metabolic factor leptin (r = 0.279). Waist circumference demonstrated significant positive correlations with triglycerides, blood glucose, adiponectin, resistin, and leptin levels. Postmenopausal women who engage in at least 150 min of MVPA weekly show lower obesity indices. There is a significant correlation between physical activity levels and obesity indicators, which relate to metabolic syndrome and energy metabolism factors. Thus, increased physical activity may help prevent metabolic syndrome and cardiovascular diseases in this population.

Acute exercise might not affect subsequent appetite responses to a fixed meal in adolescents with obesity: The SMASH exploratory study

While an intensity-dependent post-exercise decrease in energy intake (EI) has been described in adolescents with obesity, studies invariably used ad libitum meals, limiting then any conclusions regarding the effect of exercise on post-meal appetitive responses that can be also impacted by the ad libitum nature of the meal. This study analyses appetite and food-reward related responses to a fixed meal after an acute exercise, also exploring the associations between substrate use during exercise and overall daily EI in adolescents with obesity. Thirteen adolescents with obesity (12-16 years, 5 males) randomly complete 2 experimental sessions: (i) a control condition (CON); (ii) a 30-min moderate intensity (65% VO2peak) cycling condition (EX). Energy expenditure and substrate oxidation were measured during both 30 min of rest (CON) or exercise (EX). Ad libitum EI, macronutrient intake and relative EI were assessed at dinner, subjective appetite sensations taken at regular intervals and food reward measured before and after lunch as well as before dinner. Energy and macronutrient intake did not differ between conditions, as well as appetite feelings. A time effect (p = 0.012) was observed between pre and post meal for choice fat bias in both conditions but was only significant within the CON condition (p = 0.004). CHO oxidation during exercise was found correlated with both EI (r = 0.586, p = 0.045), pre-lunch hunger (r = 0.624, p = 0.030), daily AUC for hunger and DTE (r = 0.788, p = 0.002 and r = 0.695; p = 0.012 respectively). This exploratory study highlights that acute exercise might not affect subsequent appetite responses when using a fixed test meal in adolescents with obesity.

Sex differences in clinical presentation, treatment response, and side effects of nutritional therapy among patients at nutritional risk: a secondary analysis of the randomized clinical trial EFFORT

BACKGROUND

Considering sex-specific factors has become an increasingly recognized area for research and practice, in the field of clinical nutrition, there is insufficient evidence regarding differences in clinical presentation, treatment response, and side effects of nutritional therapy among female and male patients.

OBJECTIVES

We hypothesized that the clinical presentation, response to nutritional therapy, and side effects from the intervention would differ in the two sexes.

METHODS

This secondary analysis investigated differences among female and male patients at risk for malnutrition regarding initial presentation, clinical outcomes, and treatment response in patients included in the Effect of Early Nutritional Support on Frailty, Functional Outcomes, and Recovery of Malnourished Medical Inpatients Trial (EFFORT), a randomized controlled trial comparing individualized nutritional support to usual care.

RESULTS

Of 2028 patients included in the trial, 964 were females and 1064 were males. The nutritional history and clinical presentation of female patients was different: they consumed less food and had a greater loss of appetite than the male population. Male patients had higher risk for mortality at 180 d [27% compared with 19%; adjusted hazards ratio (HR): 1.35; 95% CI: 1.12, 1.63] and further adverse clinical outcomes. However, there was no difference in the effect of nutritional support on mortality among female and male patients (HR: 0.76; 95% CI: 0.45, 1.27, compared with HR: 0.81; 95% CI: 0.54, 1.21, respectively; P-interaction = 0.939).

CONCLUSIONS

Results of this multicenter randomized trial suggest that multimorbid female inpatients have a different clinical presentation and are more prone to loss of appetite and reduced daily dietary intake than male inpatients. Importantly, the favorable response to nutritional interventions was similar in both sexes. This trial was registered at clinicaltrials.gov as NCT02517476.

The Energetic Saver Profile From Sit-to-Stand Does Not Persist During Very Low-Intensity Physical Activity in Healthy Men and Women

BACKGROUND

It is essential to better characterize the energetic profile of individuals during very low-intensity physical activity. The objectives of the present study were to determine whether the saver profile from sit-to-stand persists during light physical activity and characterize patterns in substrate utilization from sit-to-stand and during very low-intensity physical activity in healthy men and women.

METHODS

Sixty-two healthy adults (38 women) performed an experimental sequence that corresponded to 15-minute sitting (SIT1), followed by 15-minute standing (STAND), 15-minute sitting again (SIT2), and finally 15 minutes of light cycling. Continuous indirect calorimetry was allowed to calculate energy expenditure (EE) and respiratory quotient through the entire sequence. Savers and nonsavers (<5% and ≥ 5% increase in EE from sitting to standing, respectively) were determined.

RESULTS

There was an interaction effect in EE between savers and nonsavers through the whole sequence (P = .008). Only nonsavers (71%) exhibited a significant increase in EE from SIT1 to STAND (P < .001). Nonsavers and savers significantly increased EE during 15 minutes of light cycling relative to sitting or standing (P < .001), without any difference between groups. The percentage of change in respiratory quotient from SIT1 to STAND was significantly different between the 2 groups, with increased values in savers and decreased values in nonsavers (P = .03). Significantly lower values in respiratory quotient and EE were found during 15 minutes of light cycling in women compared with men (P < .001).

CONCLUSIONS

It is essential to determine individuals' energetic phenotype to determine those who may benefit more from strategies such as standing or light physical activity. The sexual dimorphism in terms of substrate use during such exercise should be considered.

Physical Activity and Excess Body Weight and Adiposity for Adults. American College of Sports Medicine Consensus Statement

ABSTRACT

Excessive body weight and adiposity contribute to many adverse health concerns. The American College of Sports Medicine (ACSM) recognizes that the condition of excess body weight and adiposity is complex, with numerous factors warranting consideration. The ACSM published a position stand on this topic in 2001 with an update in 2009, and a consensus paper on the role of physical activity in the prevention of weight gain in 2019. This current consensus paper serves as an additional update to those prior ACSM position and consensus papers. The ACSM supports the inclusion of physical activity in medical treatments (pharmacotherapy, metabolic and bariatric surgery) of excess weight and adiposity, as deemed to be medically appropriate, and provides perspectives on physical activity within these therapies. For weight loss and prevention of weight gain, the effects may be most prevalent when physical activity is progressed in an appropriate manner to at least 150 min·wk-1 of moderate-intensity physical activity, and these benefits occur in a dose-response manner. High-intensity interval training does not appear to be superior to moderate-to-vigorous physical activity for body weight regulation, and light-intensity physical activity may also be an alternative approach provided it is of sufficient energy expenditure. Evidence does not support that any one single mode of physical activity is superior to other modes for the prevention of weight gain or weight loss, and to elicit holistic health benefits beyond the effects on body weight and adiposity, multimodal physical activity should be recommended. The interaction between energy expenditure and energy intake is complex, and the effects of exercise on the control of appetite are variable between individuals. Physical activity interventions should be inclusive and tailored for sex, self-identified gender, race, ethnicity, socioeconomic status, age, and developmental level. Intervention approaches can also include different forms, channels, and methods to support physical activity.

The association between the size of adipocyte-derived extracellular vesicles and fasting serum triglyceride-glucose index as proxy measures of adipose tissue insulin resistance in a rat model of early-stage obesity

Introduction

Obesity is a complex disease that predisposes individuals to cardiometabolic alterations. It leads to adipose tissue (AT) dysfunction, which triggers insulin resistance (IR). This suggests that people with obesity develop local IR first and systemic IR later. AT secretes extracellular vesicles, which may be physiopathologically associated with the development of IR. Our aim was to evaluate the effect of a high-fat diet on different parameters of adiposity in a rat model of early-stage obesity and to determine if these parameters are associated with markers of systemic IR. In addition, we sought to explore the relationship between fasting blood measures of IR (Triglycerides/High Density Lipoprotein-cholesterol [TAG/HDL-c] and Triglycerides-Glucose Index [TyG Index]) with the size of adipocyte-derived extracellular vesicles (adEV).

Methods

We used a model of diet-induced obesity for ten weeks in Wistar rats exposed to a high-fat diet. Final weight gain was analyzed by Dual X-ray absorptiometry. Visceral obesity was measured as epididymal AT weight. IR was evaluated with fasting TyG Index & TAG/HDL-c, and adEV were isolated from mature adipocytes on ceiling culture.

Results

In the high-fat diet group, glucose and triglyceride blood concentrations were higher in comparison to the control group (Log2FC, 0.5 and 1.5 times higher, respectively). The values for TyG Index and adEV size were different between the control animals and the high-fat diet group. Multiple linear regression analyses showed that adEV size can be significantly associated with the TyG Index value, when controlling for epididymal AT weight.

Conclusion

Our results show that lipid and glucose metabolism, as well as the size and zeta potential of adEV are already altered in early-stage obesity and that adEV size can be significantly associated with liver and systemic IR, estimated by TyG Index.

Cumulative effect of obesity phenotypes on body weight and body mass index

BACKGROUND

Obesity originates from an imbalance between energy intake and expenditure. Changes in energy intake components (satiation, postprandial satiety, emotional eating) and energy expenditure have been linked to obesity and are referred to as obesity phenotypes. We aim to study if these obesity phenotypes have a cumulative effect on body weight and body mass index (BMI).

SUBJECT/METHODS

This is a cross-sectional study of adult patients with obesity (BMI > 30 kg/m2) who completed the validated tests to measure the obesity phenotypes. A total of 464 were included in this study.

INTERVENTIONS/METHODS

We defined higher calories to fullness during an ad libitum meal as abnormal satiation, accelerated time to half gastric emptying with scintigraphy as abnormal postprandial satiety, higher anxiety score on the Hospital Anxiety and Depression Scale as hedonic eating behavior, and decreased percentage of measured resting energy expenditure as abnormal energy expenditure. The primary analysis was done on the number of phenotypes ( ≤ 1 and ≥ 2) with body weight and BMI using an independent t-test.

RESULTS

Our cohort included 464 patients (mean [SD] age 42.0 [10.9] years, 79% females, weight 111.2 [22.9] kg, BMI 38.9 [7.0] kg/m2). There were 294 patients who had ≤ 1 phenotype, and 170 patients with ≥ 2 phenotypes with no baseline demographical differences (i.e., age and sex). Having ≥ 2 phenotypes was associated with higher body weight (115 [25] kg vs. 109 [21] kg; p = 0.004), BMI (40 [8] kg/m2 vs. 38 [7] kg/m2; p = 0.02) and waist (118 [15] cm vs. 115 [13] cm; p = 0.04) and hip (129 [14] cm vs. 125 [13] cm; p = 0.01) circumferences compared to ≤ 1 phenotype.

CONCLUSION

Obesity phenotypes are associated with an additive effect on the body weight and BMI. Patients who have multiple obesity phenotypes may require a more aggressive approach to enhance weight loss.

Therapeutic targeting of white adipose tissue metabolic dysfunction in obesity: mechanisms and opportunities

White adipose tissue is not only a highly heterogeneous organ containing various cells, such as adipocytes, adipose stem and progenitor cells, and immune cells, but also an endocrine organ that is highly important for regulating metabolic and immune homeostasis. In individuals with obesity, dynamic cellular changes in adipose tissue result in phenotypic switching and adipose tissue dysfunction, including pathological expansion, WAT fibrosis, immune cell infiltration, endoplasmic reticulum stress, and ectopic lipid accumulation, ultimately leading to chronic low-grade inflammation and insulin resistance. Recently, many distinct subpopulations of adipose tissue have been identified, providing new insights into the potential mechanisms of adipose dysfunction in individuals with obesity. Therefore, targeting white adipose tissue as a therapeutic agent for treating obesity and obesity-related metabolic diseases is of great scientific interest. Here, we provide an overview of white adipose tissue remodeling in individuals with obesity including cellular changes and discuss the underlying regulatory mechanisms of white adipose tissue metabolic dysfunction. Currently, various studies have uncovered promising targets and strategies for obesity treatment. We also outline the potential therapeutic signaling pathways of targeting adipose tissue and summarize existing therapeutic strategies for antiobesity treatment including pharmacological approaches, lifestyle interventions, and novel therapies.

Interindividual variability in appetitive sensations and relationships between appetitive sensations and energy intake

BACKGROUND

Appetitive sensations (AS) are signals that guide eating behaviors. Marked short-term inter-individual variability in AS has been reported but the long-term stability of individual ratings and their dietary implications are not well characterized.

OBJECTIVES

This study explored the stability of inter-individual ratings of hunger, fullness and thirst for 17 weeks; determined the relationships between these sensations, eating patterns and energy intake (EI); as well as the associations between ratings and selected individual characteristics (age, gender, BMI).

METHODS

A 17-week observational study collected hourly appetitive ratings and dietary intake data from 97 (90 completers, 7 partial completers) healthy adults at weeks 1, 9, and 17.

RESULTS

There were marked and stable inter-individual differences over the 17 weeks for hunger (week 1 vs. week 9, r = 0.72 (p < 0.001); week 1 vs. week 17, r = 0.67 (p < 0.001); week 9 vs. week 17, r = 0.77 (p < 0.001)); fullness (week 1 vs. week 9 r = 0.74 (p < 0.001); week 1 vs. week 17, r = 0.71 (p < 0.001); week 9 vs. week 17, r = 0.81 (p < 0.001)); and thirst (week 1 vs. week 9 r = 0.82 (p < 0.001); week 1 vs. week 17, r = 0.81 (p < 0.001); week 9 vs. week 17, r = 0.88 (p < 0.001)). Cross-correlation functions revealed EI and eating pattern exerted stronger effects on AS than the reverse. However, the absolute effect sizes were small. Path analyses also indicated that there were weak relationships between AS and EI. No robust effects of the studied individual characteristics were observed.

CONCLUSION

This study found that acute and chronic sensations of hunger, fullness and thirst are relatively stable within individuals but vary markedly between individuals. In addition, the present data indicate AS are poorly associated with dietary patterns or with EI under conditions of relatively stable energy balance.

Mediating effect of lower extremity muscle on the relationship between obesity and osteoarthritis in middle-aged and elderly women in Korea: based on the 2009-2011 Korea National Health and Nutrition Examination Survey

OBJECTIVES

This study investigated whether the lower extremity muscle mass index (LMI) mediates the relationship between general obesity, central obesity, and knee osteoarthritis in middle-aged and elderly women in Korea.

METHODS

Data of 2,843 women aged ≥50 years were collected from the Korean National Health and Nutrition Examination Survey conducted between 2009 and 2011. General obesity and central obesity were evaluated based on body mass index (BMI) and waist circumference (WC), calculated through anthropometric measurements and body composition assessments. LMI was calculated by dividing the muscle mass in both legs-measured using the dual-energy X-ray absorptiometry-by body weight. Knee osteoarthritis was defined as a Kellgren-Lawrence scale (KL) grade of ≥2 as assessed through radiographic images.

RESULTS

Knee osteoarthritis prevalence, indicated by KL grades, was significantly higher in the general obesity and central obesity groups compared to the normal group, and conversely, lower with varying LMI levels. Using mediation analysis with bootstrapping and adjusting for covariates, we found that LMI mediated the relationship between BMI and KL (β, 0.005; 95% confidence interval [CI], 0.000 to 0.010) and WC and KL grade (β, 0.002; 95% CI, 0.001 to 0.003), explaining 4.8% and 6.7% of the total effects of BMI and WC on KL grade, respectively.

CONCLUSIONS

The study suggested that LMI partially mediates the link between general obesity and/or central obesity and knee osteoarthritis, proposing that a higher proportion of lower limb muscle mass relative to body weight can alleviate the increased risk of knee osteoarthritis caused by obesity.

Higher energy flux may improve short-term appetite control in adolescents with obesity: the NEXT study

Recent evidence suggests better appetite control in states of high-energy flux (HEF) in adults and lean children. Nevertheless, it is unknown whether this extends to youth with obesity. This study compares the effects of low, moderate or HEF on short-term appetitive control in adolescents with obesity. Sixteen adolescents with obesity (12-16 years, Tanner stages 3-5, 11 females) randomly completed three conditions: (i) low-energy flux (LEF); (ii) moderate energy flux (MEF; + 250 kcal) and (iii) HEF (HEF; + 500 kcal). Energy flux was achieved in MEF and HEF through elevated energy intake (EI) and concomitant increase in energy expenditure using cycling exercise (65 % VO2peak). Ad libitum EI, macronutrient intake and relative EI were assessed at dinner, subjective appetite sensations taken at regular intervals and food reward measured before dinner. Ad libitum EI at dinner was greater in LEF compared with HEF (P = 0·008), and relative EI (REI) was higher in LEF compared with MEF (P = 0·003) and HEF (P < 0·001). The absolute consumption of carbohydrates was lower in LEF compared with MEF (P = 0·047) and HEF (P < 0·001). Total AUC for hunger and desire to eat was lower in HEF compared with LEF (P < 0·001) and MEF (P = 0·038). Total AUC for prospective food consumption was lower on HEF compared with LEF (P = 0·004). Food choice sweet bias was higher in HEF (P = 0·005) compared with LEF. To conclude, increasing energy flux may improve short-term appetite control in adolescents with obesity.

Inter-individual differences in children's short-term energy compensation: a systematic review and meta-analysis

BACKGROUND

The ability to regulate energy intake is often assessed using a preloading paradigm to measure short-term energy compensation. In children, large variability exists with this paradigm both within- and across- studies and is poorly understood.

OBJECTIVES

This systematic review and meta-analysis aimed to better understand factors contributing to variability in children's energy compensation. We tested 1) whether children demonstrated "good" energy compensation, defined as adjusting meal intake commensurate with preload intake and 2) differences in children's energy compensation by child age, sex, and weight status (assessed both continuously and categorically).

METHODS

Standard guidelines for systematic review were followed to search PubMed, PsychInfo, and Web of Science. Data on study design (preload form, preload-to-meal interval, preload energy difference, study setting) and participant characteristics (sex, age, weight status) were extracted from 29 experiments meeting inclusion criteria, and 13 were included in meta-analyses. COMPx (energy compensation index), a linear transformation comparing food intake following a high- vs. low-energy preload, was the outcome. Hedge's g was calculated, and random intercept-only models tested associations between COMPx and sex, age, and weight status.

RESULTS

The systematic review revealed mixed results regarding children's energy compensation and the role of inter-individual differences. Meta-analytic models revealed that children undercompensated (overate) for preload energy (β = -0.38; P = 0.008). Sex (β = 0.11; P = 0.76), age (β = 0.03; P = 0.75), and weight (assessed continuously; β = -0.07, P = 0.37) were not related to compensation. Children with overweight/obesity (assessed categorically) undercompensated more than children with healthy weight (β = 0.18; P = 0.04).

CONCLUSIONS

The systematic review highlighted wide variability across studies, while the meta-analysis demonstrated differences in COMPx by child weight status but not by age or sex. Standardizing protocols across studies is recommended, along with designing adequately powered studies aiming to test inter-individual differences a priori. Alternative approaches to the use of COMPx are recommended to allow better characterization of children's energy compensation ability. This study was registered at PROSPERO as CRD42020197748.

Variation in executive function relates to BMI increases in youth who were initially of a healthy weight in the ABCD Study

OBJECTIVE

The study aim was to determine whether (A) differences in executive function (EF) and cognition precede weight gain or (B) weight gain causes changes to EF and cognition.

METHODS

Data were gathered from the Adolescent Brain Cognitive Development (ABCD) Study (release 4.0; ages 9-12 years old [N = 2794]; 100% had healthy weight at baseline [i.e., 9/10 years old], 12.4% had unhealthy weight by ages 11/12 years). EF and cognition were assessed across several domains (e.g., impulsivity, inhibitory control, processing speed, memory); BMI was calculated from height and weight. Nested random-effects mixed models examined (A) BMI ~ EF × Time (i.e., variation in EF/cognition precedes weight gain) and (B) EF ~ BMI × Time (weight gain causes changes to EF/cognition) and controlled for sex, puberty, and caregiver education; random effects were site and subject.

RESULTS

Variation in impulsivity, memory, learning, and processing speed was associated with greater increases in BMI trajectories from 9 to 12 years old. Weight gain was associated with a decrease in inhibitory control, but no other associations were observed.

CONCLUSIONS

Underlying variation in EF and cognition may be important for weight gain, but 2 years of weight gain may not be enough to have clinical implications for EF and cognition beyond inhibitory control. These findings suggest that more attention should be paid to the inclusion of EF programs in obesity prevention efforts.

Assessing daily energy intake in adult women: validity of a food-recognition mobile application compared to doubly labelled water

Accurate dietary assessment is crucial for nutrition and health research. Traditional methods, such as food records, food frequency questionnaires, and 24-hour dietary recalls (24HR), have limitations, such as the need for trained interviewers, time-consuming procedures, and inaccuracies in estimations. Novel technologies, such as image-based dietary assessment apps, have been developed to overcome these limitations. SNAQ is a novel image-based food-recognition app which, based on computer vision, assesses food type and volume, and provides nutritional information about dietary intake. This cross-sectional observational study aimed to investigate the validity of SNAQ as a dietary assessment tool for measuring energy and macronutrient intake in adult women with normal body weight (n = 30), compared to doubly labeled water (DLW), a reference method for total daily energy expenditure (TDEE). Energy intake was also estimated using a one-day 24HR for direct comparison. Bland-Altman plots, paired difference tests, and Pearson's correlation coefficient were used to assess agreement and relationships between the methods. SNAQ showed a slightly higher agreement (bias = -329.6 kcal/day) with DLW for total daily energy intake (TDEI) compared to 24HR (bias = -543.0 kcal/day). While both SNAQ and 24HR tended to underestimate TDEI, only 24HR significantly differed from DLW in this regard (p < 0.001). There was no significant relationship between estimated TDEI and TDEE using SNAQ (R2 = 27%, p = 0.50) or 24HR (R2 = 34%, p = 0.20) and there were no significant differences in energy and macronutrient intake estimates between SNAQ and 24HR (Δ = 213.4 kcal/day). In conclusion, these results indicate that SNAQ provides a closer representation of energy intake in adult women with normal body weight than 24HR when compared to DLW, but no relationship was found between the energy estimates of DLW and of the two dietary assessment tools. Further research is needed to determine the clinical relevance and support the implementation of SNAQ in research and clinical settings. Clinical trial registration: This study is registered on ClinicalTrials.gov with the unique identifier NCT04600596 (https://clinicaltrials.gov/ct2/show/NCT04600596).

Hunger & satiety signals: another key mechanism involved in the NAFLD pathway

Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent metabolic disease, although prevalence could change according to region, nowadays is considered a public health problem whose real impact on the health system is unknown. NAFLD has a multifactorial and complex pathophysiology, due to this, developing a unique and effective pharmacological treatment has not been successful in reverting or avoiding the progression of this liver disease. Even though NAFLD pathophysiology is known, all actual treatments are focused on modifying or regulating the metabolic pathways, some of which interplay with obesity. It has been known that impairments in hunger and satiety signals are associated with obesity, however, abnormalities in these signals in patients with NAFLD and obesity are not fully elucidated. To describe these mechanisms opens an additional option as a therapeutic target sharing metabolic pathways with NAFLD, therefore, this review aims to describe the hormones and peptides implicated in both hunger-satiety in NAFLD. It has been established that NAFLD pharmacological treatment cannot be focused on a single purpose; hence, identifying interplays that lead to adding or modifying current treatment options could also have an impact on another related outcome such as hunger or satiety signals.

Measured vs estimated resting energy expenditure in children and adolescents with obesity

Pediatric obesity requires early targeted interventions consisting mainly of a low-calorie diet prescribed based on resting energy expenditure (REE), often estimated through predictive equations. The aim of this study was to define the prevalence of "hypo-", "normo-" and "hypermetabolic" in a large cohort of children and adolescents with obesity by comparing measured and estimated REE and to evaluate the characteristics related to these metabolic statuses in both males and females. The study population was divided into the three subgroups by comparing REE measured using indirect calorimetry and estimated using the Molnar equation, and subsequently analyzed. The majority of the participants (60.6%) were normometabolic, 25.5% hypermetabolic and 13.9% hypometabolic. No significant differences in age, Tanner stage, systolic blood pressure, or the presence of metabolic syndrome were found. However, the hypermetabolic subgroup was significantly lighter, shorter, with lower hip and waist circumferences, had a greater amount of fat-free mass and lower fat mass, significantly lower diastolic blood pressure, and a significantly higher frequency of non-alcoholic liver steatosis. Pediatric obesity is more associated with normal or increased REE than with a hypometabolic condition, suggesting that estimation of energy expenditure with predictive equations is still inadequate for prescribing the appropriate diet plan.

Appetite, Energy Expenditure, and the Regulation of Energy Balance

At usual weight, energy intake and expenditure are coupled and covary to maintain body weight (energy stores). A change in energy balance, especially weight loss, invokes discoordinated effects on energy intake and output that favor return to previous weight. These regulatory systems reflect physiological changes in systems regulating energy intake and expenditure rather than a lack of resolve. The biological and behavioral physiology of dynamic weight change are distinct from those of attempts at static weight maintenance of an altered body weight. This suggests that optimal therapeutic approaches to losing or gaining vs. sustaining weight changes are different for most individuals.

A qualitative study exploring the perceptions of health among pre-teen girls from disadvantaged communities in Dublin

There are disparities in health outcomes between youth from higher and lower socioeconomic backgrounds, and girls are especially vulnerable to changes in health-related behaviours as they develop. Therefore, this study explored how girls from disadvantaged communities in Dublin, Ireland, make sense of 'being healthy.' A phenomenological qualitative design was implemented. Three focus groups were conducted (n = 22, 10-12 years) and data were analysed using thematic analysis. Food and physical appearance featured prominently within the girls' definitions of health. Girls and their families from low-SES backgrounds may experience more difficulties with time scarcity as well as environmental barriers to a healthy lifestyle.

Downregulation of fatty acid oxidation led by Hilpda increases G2/M arrest/delay-induced kidney fibrosis

Hypoxia-regulated proximal tubular epithelial cells (PTCs) G2/M phase arrest/delay was involved in production of renal tubulointerstitial fibrosis (TIF). TIF is a common pathological manifestation of progression in patients with chronic kidney disease (CKD), and is often accompanied by lipid accumulation in renal tubules. However, cause-effect relationship between hypoxia-inducible lipid droplet-associated protein (Hilpda), lipid accumulation, G2/M phase arrest/delay and TIF remains unclear. Here we found that overexpression of Hilpda downregulated adipose triglyceride lipase (ATGL) promoted triglyceride overload in the form of lipid accumulation, leading to defective fatty acid β-oxidation (FAO), ATP depletion in a human PTC cell line (HK-2) under hypoxia and in mice kidney tissue treated with unilateral ureteral obstruction (UUO) and unilateral ischemia-reperfusion injury (UIRI). Hilpda-induced lipid accumulation caused mitochondrial dysfunction, enhanced expression of profibrogenic factors TGF-β1, α-SMA and Collagen I elevation, and reduced expression of G2/M phase-associated gene CDK1, as well as increased CyclinB1/D1 ratio, resulted in G2/M phase arrest/delay and profibrogenic phenotypes. Hilpda deficiency in HK-2 cell and kidney of mice with UUO had sustained expression of ATGL and CDK1 and reduced expression of TGF-β1, Collagen I and CyclinB1/D1 ratio, resulting in the amelioration of lipid accumulation and G2/M arrest/delay and subsequent TIF. Expression of Hilpda correlated with lipid accumulation, was positively associated with tubulointerstitial fibrosis in tissue samples from patients with CKD. Our findings suggest that Hilpda deranges fatty acid metabolism in PTCs, which leads to G2/M phase arrest/delay and upregulation of profibrogenic factors, and consequently promote TIF which possibly underlie pathogenesis of CKD.

Link between emotional and external eating behaviors, peripheral neuropeptide Y, and β-hydroxybutyrate in participants with obesity on 12-week ketogenic diet

Objective: Understanding the impact of stress on emotional and external eating behaviors and the psychological and the associated metabolic factors can help in designing subsequent interventions to protect health. In particular, psychological trait-like construct related to eating has been shown to be an important target for intervention. Methods and measures: This study aimed to investigate the biochemical variables associated with a decrease in emotional and external eating behaviors due to 12-week ketogenic diet (12KD) in 35 adult participants (12 males) with obesity. Results: Absolute changes in emotional and external eating were independent of changes in body mass, nutritional intake, and Δ cortisol, but were predicted with increases in serum β-hydroxybutyrate (BHB) and decreases in serum peripheral neuropeptide Y (pNPY) (all p's < 0.050). Decrease in pNPY was also associated with an increase in BHB but was independent of anthropometrical changes, Δ fasting glucose, and Δ insulin. Conclusion: The reductions in emotional and external eating behaviors in participants with obesity were uniquely predicted by an increase in BHB and a decrease in pNPY after 12KD. In ketosis, emotional and external eating dropped independently of body mass change. Change in pNPY predicted changes in emotional and external eating. The role of BHB in modulating eating behavior should be further explored.

A comparison of meal-related appetite, food reward and eating behaviour traits in people with and without spinal cord injury

Persons with a spinal cord injury (SCI) are at a heightened risk of obesity. However, little is known about the effect of SCI on factors that influence energy intake. This study compared measures of food reward, eating behaviour traits, and appetite perceptions between adults with and without SCI. Twenty wheelchair dependent persons with chronic (>1 year) SCI (C1-T12) and twenty non-SCI individuals matched for BMI, age and sex participated. Following a familiarisation visit, participants consumed a breakfast meal, normalised for resting metabolic rate (RMR), and provided subjective appetite perceptions every 30 min for 4 h. Subsequently, energy intake was determined via an ad libitum lunch meal. Explicit liking, explicit wanting, implicit wanting and relative preference were assessed in a hungry and fed state via the Leeds Food Preference Questionnaire prior to and following the lunch meal. Eating behaviour traits were assessed via the Adult Eating Behaviour Questionnaire, Control of Eating Questionnaire, Reasons Individuals Stop Eating Questionnaire, and Three-Factor Eating Questionnaire Revised 18-item version. Sweet appeal bias was greater for explicit liking, explicit wanting, and relative preference in the group with SCI compared to the non-SCI group (p ≤ 0.024). The group with SCI also reported higher levels of cognitive restraint and satiety responsiveness (p ≤ 0.029). No group differences in postprandial appetite perceptions (p ≥ 0.690) or energy intake relative to RMR were seen (p = 0.358). However, the group with SCI demonstrated a trend toward a lower absolute energy intake (p = 0.063). In conclusion, food reward for sweet foods was greater in the group with SCI. Further, our findings suggest that acute appetite perceptions, including satiety profiles, are not different between persons with and without SCI.

Predictive Equations Overestimate Resting Metabolic Rate in Young Chilean Women with Excess Body Fat

Underestimating/overestimating resting metabolic rate (RMR) affects energy prescription. The objective was to compare RMR by indirect calorimetry (RMR IC) and RMR estimated by predictive equations in women with excess body fat. This was an analytical cross-sectional study with 41 women aged 18-28 with overnutrition according to body composition. The RMR IC was measured and RMR estimated using the FAO/WHO/UNU (1985), FAO/WHO/UNU (2004), Harris-Benedict, and Mifflin-St Jeor equations. The percentage of adequacy (90-110%), overestimation (>110%), and underestimation (<90%) were evaluated for RMR IC. Data were described by percentiles because of non-normal distribution according to the Shapiro-Wilk test. The Kruskal-Wallis test and Bland-Altman analysis were applied at a significance level of α < 0.05. The RMR IC was 1192 and 1183 calories/day (p = 0.429) in women with obesity and overweight, respectively. The FAO/WHO/UNU (1985), FAO/WHO/UNU (2004), Harris-Benedict, and Mifflin-St Jeor equations overestimated the RMR IC by 283.2, 311.2, 292.7, and 203.0 calories/day and by 296.7, 413.8, 280.0, and 176.6 calories/day for women with overweight and obesity (p < 0.001), respectively. The Harris-Benedict adjusted weight (0.5) equation underestimated RMR IC by 254.7 calories/day. The predictive equations overestimated RMR IC in women with excess body fat. The Mifflin-St Jeor equation showed less overestimation and better adequacy, but was not exempt from inaccuracy.

Physiologic and Behavioral Correlates of Energy Intake in Emerging Adulthood: Cross-Sectional Analysis of the RIGHT Track Health Study

BACKGROUND

Consistent findings have reported that FFM is associated with EI. However, conjoint assessments of physiologic (body composition, fasting serum leptin) and behavioral [eating behaviors and physical activity (PA)] correlates of EI during emerging adulthood have not been examined.

OBJECTIVES

We assessed associations between physiologic and behavioral correlates of EI within the context of one another in emerging adults (18-28 years old). We also assessed these associations in a subsample after the removal of probable EI underreporters.

METHODS

Cross-sectional data from 244 emerging adults (age = 19.6 ± 1.4 y; BMI = 26.4 ± 6.6 kg/m2; 56.6% female) from the RIGHT Track Health study were used. Measures included body composition (BOD POD), eating behaviors (Three-Factor Eating Questionnaire), objective and subjective PA (accelerometer-derived total activity counts and Godin-Shephard Leisure-Time Exercise Questionnaire), fasting serum leptin, and EI (three 24-hour dietary recalls). Correlates independently associated with EI were entered into a backward stepwise linear regression model. Correlates that met the criteria of P < 0.05 were retained. Analyses were repeated in a subsample after removing probable EI underreporters (n = 48). Effect modification by sex (male and female) and BMI (BMI < 25 kg/m2, BMI ≥ 25 kg/m2) categories was also assessed.

RESULTS

In the full sample, FFM (β: 18.4; 95% CI: 9.9, 26.8), leptin (β: -84.8; 95% CI: -154.3, -15.4), dietary restraint (β: -35.2; 95% CI: -59.1, -11.3), and subjective PA (β: 2.5; 95% CI: 0.04, 4.9) were significantly associated with EI. After the removal of probable underreporters, only FFM remained significantly associated with EI (β: 43.9; 95% CI: 27.2, 60.6). No evidence of effect modification by sex or BMI categories was noted.

CONCLUSIONS

Although physiologic and behavioral correlates were associated with EI in the full sample, only FFM remained a robust correlate of EI in a subsample of emerging adults after removing probable EI underreporters.

Changes in maternal and paternal body composition during the transition to parenthood (TRANSPARENTS)

OBJECTIVE

The transition to parenthood might negatively influence health-related behavior and can result in increased adiposity. The aim of this study was to investigate how body composition in mother-father dyads changes from pregnancy up to 6 months post partum.

METHODS

Anthropometrics were collected from 144 nulliparous couples at 12 weeks of gestation (PG12) and 6 weeks (PP6WK) and 6 months (PP6M) post partum. A longitudinal dyadic confirmatory factor analysis model was used to analyze changes in body composition. Body composition was treated as a latent variable using BMI, body fat percentage, and waist circumference as indicators.

RESULTS

For women, latent means increased at 6 weeks post partum (PP6WK - PG12: +1.115, SE: 0.117, p < 0.001), decreased again at 6 months post partum (PP6M - PP6WK: -0.368, SE: 0.107, p < 0.001), but remained above baseline levels (PP6M - PG12: +0.747; SE: 0.115, p < 0.001). For men, the latent means at follow-up were higher than at baseline (PP6WK-PG12: +0.370, SE: 0.075; PP6M-PG12: +0.366, SE: 0.084, both p < 0.001).

CONCLUSIONS

Increases in latent means correspond to unfavorable changes in BMI, body fat percentage, and waist circumference. These changes were observed from the beginning of pregnancy up to 6 months post partum. Weight management for both women and men during pregnancy and the early postpartum period is recommended and fathers should be included in pre- and postnatal standard care.

Smartphone Usage Patterns and Dietary Risk Factors in Adolescents

BACKGROUND

Whereas earlier studies have shown that traditional screen time such as TV watching influences dietary behaviors in adolescents, little is known about the effects of modern screen time such as smartphone use.

OBJECTIVES

We examined the associations of smartphone usage duration and content type with dietary risk factors among adolescents.

METHODS

We conducted a cross-sectional analysis using a nationally representative sample of 54,601 middle- and high-school students (aged 12-18 y; 26,928 boys and 27,673 girls) in the Korea Youth Risk Behavior Web-Based Survey 2017. Smartphone use (average duration and most frequently used content type) and dietary intakes [frequent breakfast skipping; less frequent intakes of fruits and vegetables; more frequent intakes of instant noodles, fast food, chips/crackers, and sugar-sweetened beverages (SSBs)] were self-reported via an online-based questionnaire. Multivariable logistic regression was performed to estimate ORs and 95% CIs for the associations of smartphone usage duration and content type with prevalence of dietary risk factors, adjusting for potential confounders. All analyses accounted for complex survey sampling.

RESULTS

Prolonged smartphone use (≥300 compared with 1-59 min/d) was associated with (OR; 95% CI) higher prevalence of frequent breakfast skipping (1.60; 1.45, 1.76); frequent intakes of instant noodles (1.65; 1.47, 1.84), fast food (1.36; 1.20, 1.53), and SSBs (1.92; 1.75, 2.11); and less frequent intakes of fruits (1.44; 1.30, 1.59) and vegetables (1.32; 1.18, 1.47). Adjusting for usage duration, using smartphones mainly for messenger/e-mail, social networking service (SNS)/forum, and games were associated with less frequent intakes of fruits (OR: 1.21; 95% CI: 1.12, 1.31; OR: 1.28; 95% CI: 1.17, 1.40; and OR: 1.20; 95% CI: 1.10, 1.32, respectively) and vegetables (OR: 1.24; 95% CI: 1.12, 1.37; OR: 1.26; 95% CI: 1.13, 1.40; and OR: 1.25; 95% CI: 1.12, 1.40, respectively) than was using smartphones for education/information search. Using smartphones mainly for messenger/e-mail (OR: 1.24; 95% CI: 1.14, 1.35) and SNS/forum (OR: 1.18; 95% CI: 1.08, 1.29) were also associated with more frequent intake of SSBs.

CONCLUSIONS

Our data suggest that both duration and content type of smartphone use are independently associated with dietary risk factors among adolescents.

Posture economy: the importance of metabolic state on metabolic phenotype assessment and the energy cost of sitting and standing. A whole body calorimetry trial

BACKGROUND

Metabolic state (fed vs fasted) can result in marked differences in exercise metabolism, fat, and carbohydrate oxidation. In addition, a large inter-individual range in metabolic response to sitting and standing when fasted has been observed. Here, we examined the effect of metabolic state on the energy cost of posture allocation.

METHODS

Thirty male participants were recruited and followed a 1 h sit-stand protocol in a fasted and fed state inside a whole body calorimeter to measure energy expenditure (EE) and respiratory quotient (RQ). Body composition and resting metabolic rate were measured before the start. Fasted EE response was used to phenotype participants as energy savers (≤5% ΔEE from sitting to standing) or energy spenders (>5% ΔEE).

RESULTS

In a fasted state, ΔEE from sitting to standing in energy spenders was 10.2 ± 2.7% compared to 2.6 ± 1.9% in energy savers (p < 0.001). Postprandial, there was no difference in ΔEE between energy spenders and energy savers (10.8 ± 5.1% vs 9.4 ± 5.7%). In a fasted state, significant correlations were observed between body fat (%) and ΔEE (%) (R² = 0.55, p < 0.001), body fat (%) and ΔRQ (R² = 0.28, p < 0.001) and ΔEE (%) and ΔRQ (R² = 0.43, p < 0.001); these correlations were not present after the meal.

CONCLUSIONS

The current study showed for the first time, that the observed difference between energy spenders and energy savers in a fasted state, disappeared after the consumption of a meal. Therefore, metabolic state may be important to consider when assessing metabolic phenotypes. Differences in body composition were observed between the energy spender and energy saver phenotype. The current findings may have implications on health and weight management recommendations on posture to increase non-exercise activity thermogenesis. This trial was retrospectively registered on 19 December 2017 as NCT03378115 on Clinicaltrials.gov .

Anti-adipogenic and Pro-lipolytic Effects on 3T3-L1 Preadipocytes by CX-4945, an Inhibitor of Casein Kinase 2

Casein kinase 2 (CK2) is a ubiquitously expressed serine/threonine kinase and is upregulated in human obesity. CX-4945 (Silmitasertib) is a CK2 inhibitor with anti-cancerous and anti-adipogenic activities. However, the anti-adipogenic and pro-lipolytic effects and the mode of action of CX-4945 in (pre)adipocytes remain elusive. Here, we explored the effects of CX-4945 on adipogenesis and lipolysis in differentiating and differentiated 3T3-L1 cells, a murine preadipocyte cell line. CX-4945 at 15 μM strongly reduced lipid droplet (LD) accumulation and triglyceride (TG) content in differentiating 3T3-L1 cells, indicating the drug’s anti-adipogenic effect. Mechanistically, CX-4945 reduced the expression levels of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and perilipin A in differentiating 3T3-L1 cells. Strikingly, CX-4945 further increased the phosphorylation levels of cAMP-activated protein kinase (AMPK) and liver kinase B-1 (LKB-1) while decreasing the intracellular ATP content in differentiating 3T3-L1 cells. In differentiated 3T3-L1 cells, CX-4945 had abilities to stimulate glycerol release and elevate the phosphorylation levels of hormone-sensitive lipase (HSL), pointing to the drug’s pro-lipolytic effect. In addition, CX-4945 induced the activation of extracellular signal-regulated kinase-1/2 (ERK-1/2), and PD98059, an inhibitor of ERK-1/2, attenuated the CX4945-induced glycerol release and HSL phosphorylation in differentiated 3T3-L1 cells, indicating the drug’s ERK-1/2-dependent lipolysis. In summary, this investigation shows that CX-4945 has strong anti-adipogenic and pro-lipolytic effects on differentiating and differentiated 3T3-L1 cells, mediated by control of the expression and phosphorylation levels of CK2, C/EBP-α, PPAR-γ, FAS, ACC, perilipin A, AMPK, LKB-1, ERK-1/2, and HSL.

IL-1R-IRAKM-Slc25a1 signaling axis reprograms lipogenesis in adipocytes to promote diet-induced obesity in mice

Toll-like receptors/Interleukin-1 receptor signaling plays an important role in high-fat diet-induced adipose tissue dysfunction contributing to obesity-associated metabolic syndromes. Here, we show an unconventional IL-1R-IRAKM-Slc25a1 signaling axis in adipocytes that reprograms lipogenesis to promote diet-induced obesity. Adipocyte-specific deficiency of IRAKM reduces high-fat diet-induced body weight gain, increases whole body energy expenditure and improves insulin resistance, associated with decreased lipid accumulation and adipocyte cell sizes. IL-1β stimulation induces the translocation of IRAKM Myddosome to mitochondria to promote de novo lipogenesis in adipocytes. Mechanistically, IRAKM interacts with and phosphorylates mitochondrial citrate carrier Slc25a1 to promote IL-1β-induced mitochondrial citrate transport to cytosol and de novo lipogenesis. Moreover, IRAKM-Slc25a1 axis mediates IL-1β induced Pgc1a acetylation to regulate thermogenic gene expression in adipocytes. IRAKM kinase-inactivation also attenuates high-fat diet-induced obesity. Taken together, our study suggests that the IL-1R-IRAKM-Slc25a1 signaling axis tightly links inflammation and adipocyte metabolism, indicating a potential therapeutic target for obesity.

Beyond appetite regulation: Targeting energy expenditure, fat oxidation, and lean mass preservation for sustainable weight loss

New appetite-regulating antiobesity treatments such as semaglutide and agents under investigation such as tirzepatide show promise in achieving weight loss of 15% or more. Energy expenditure, fat oxidation, and lean mass preservation are important determinants of weight loss and weight-loss maintenance beyond appetite regulation. This review discusses prior failures in clinical development of weight-loss drugs targeting energy expenditure and explores novel strategies for targeting energy expenditure: mitochondrial proton leak, uncoupling, dynamics, and biogenesis; futile calcium and substrate cycling; leptin for weight maintenance; increased sympathetic nervous system activity; and browning of white fat. Relevant targets for preserving lean mass are also reviewed: growth hormone, activin type II receptor inhibition, and urocortin 2 and 3. We endorse moderate modulation of energy expenditure and preservation of lean mass in combination with efficient appetite reduction as a means of obtaining a significant, safe, and long-lasting weight loss. Furthermore, we suggest that the regulatory guidelines should be revisited to focus more on the quality of weight loss and its maintenance rather than the absolute weight loss. Commitment to this research focus both from a scientific and from a regulatory point of view could signal the beginning of the next era in obesity therapies.

Effects of Three Different Modes of Resistance Training on Appetite Hormones in Males With Obesity

Purpose

This study explored the effect of three different modes of resistance training on appetite hormones [leptin, ghrelin, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide tyrosine–tyrosine (PYY)], cardiometabolic and anthropometric measures in males with obesity.

Methods

Forty-four males with obesity (age: 27.5 ± 9.4 yrs.; mean weight: 93.2 ± 2.2 kg, body mass index: 32.9 ± 1.2 kg/m²) were randomized to traditional resistance training (TRT, n = 11), circuit resistance training (CRT, n = 11), interval resistance training (IRT, n = 11) or control (C, n = 11) groups. All resistance training groups received 50 min of supervised training per session, three days per week, for 12 weeks. Measurements were taken at baseline and after 12 weeks of training.

Results

Plasma levels of leptin, ghrelin, CCK, and PYY decreased significantly in all three different modalities of resistance training groups when compared to the control group (p < 0.05). GLP-1 increased significantly in both CRT and IRT groups compared to TRT and C groups (p < 0.05). Glucose-dependent insulinotropic polypeptide decreased significantly in CRT and IRT groups compared to the C group (p < 0.05). Adiponectin levels increased significantly in all resistance training groups compared to the C group (p < 0.05).

Conclusion

Overall, CRT and IRT protocols had the greatest impact on appetite hormones compared to individuals who engaged in TRT or did not exercise (C).

Trends of central obesity and associations with nutrients intake and daily behaviors among women of childbearing age in China

Background

Obesity among women of childbearing age has becoming an important public health concern. We aimed to describe the trends of central obesity among Chinese women of childbearing age from 2004 to 2011 and to examine its associations with nutrients intake and daily behaviors.

Methods

Longitudinal data were derived from the China Health and Nutrition Survey. Participants consisted of 2481 women aged 15–44 years old. WC (Waist circumference) and WHtR (Waist to height ratio) were adopted as indicators of central obesity. Generalized linear mixed model was performed to analyze the associations of nutrients intake and daily behaviors with central obesity.

Results

From 2004 to 2011, the prevalence of central obesity among Chinese women of childbearing age increased from 21.6 to 30.7% (WC as indice) or from 22.8 to 32.6% (WHtR as indice) (both p < 0.001). Protein intake above the AMDR (Acceptable macronutrient distribution range) (OR = 1.21, 95% CI 1.05–1.39, p < 0.01) and non-participation in LTPA (Leisure time physical activity) (OR = 1.45, 95% CI 1.17–1.80, p < 0.001) were risk factors for high WC, and the latter was also associated with high WHtR (OR = 1.36, 95% CI 1.10–1.67, p < 0.01). For those women who had high WC & high WHtR, the impacts of protein intake and LTPA became stronger, especial LTPA (OR = 1.53, 95% CI 1.21–1.94, p < 0.001). Age-stratified analyses found that non-participation in LTPA was key factor for central obesity in 15–34 age group, while protein intake above the AMDR was pronounced in the 35–44 age group.

Conclusions

Non-participation in LTPA and protein intake above the AMDR were significant contributors of central obesity, which could be intervention targets to deal with the growing trend of central obesity among women of childbearing age.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-022-01600-9.

The magnitude and progress of lean body mass, fat-free mass, and skeletal muscle mass loss following bariatric surgery: A systematic review and meta-analysis

Postbariatric loss of muscle tissue could negatively affect long-term health due to its role in various bodily processes, such as metabolism and functional capacity. This meta-analysis aimed to unravel time-dependent changes in the magnitude and progress of lean body mass (LBM), fat-free mass (FFM), and skeletal muscle mass (SMM) loss following bariatric surgery. A systematic literature search was conducted in Pubmed, Embase, and Web of Science. Fifty-nine studies assessed LBM (n = 37), FFM (n = 20), or SMM (n = 3) preoperatively and ≥1 time points postsurgery. Random-effects meta-analyses were performed to determine pooled loss per outcome parameter and follow-up time point. At 12-month postsurgery, pooled LBM loss was -8.13 kg [95%CI -9.01; -7.26]. FFM loss and SMM loss were -8.23 kg [95%CI -10.74; -5.73] and -3.18 kg [95%CI -5.64; -0.71], respectively. About 55% of 12-month LBM loss occurred within 3-month postsurgery, followed by a more gradual decrease up to 12 months. Similar patterns were seen for FFM and SMM. In conclusion, >8 kg of LBM and FFM loss was observed within 1-year postsurgery. LBM, FFM, and SMM were predominantly lost within 3-month postsurgery, highlighting that interventions to mitigate such losses should be implemented perioperatively.

Intervening on exercise and daylong movement for weight loss maintenance in older adults: A randomized, clinical trial

OBJECTIVE

This study aimed to determine the impact of dietary weight loss (WL) plus aerobic exercise (EX) and a "move more, more often" approach to activity promotion (SitLess; SL) on WL and maintenance.

METHODS

Low-active older adults (age 65-86 years) with obesity were randomized to WL+EX, WL+SL, or WL+EX+SL. Participants received a social-cognitive group-mediated behavioral WL program for 6 months, followed by a 12-month maintenance period. EX participants received guided walking exercise with the goal of walking 150 min/wk. SL attempted to achieve a step goal by moving frequently during the day. The primary outcome was body weight at 18 months, with secondary outcomes including weight regain from 6 to 18 months and objectively assessed physical activity and sedentary behavior at each time point.

RESULTS

All groups demonstrated significant WL over 6 months (p < 0.001), with no group differences. Groups that received SL improved total activity time (p ≤ 0.05), and those who received EX improved moderate-to-vigorous activity time (p = 0.003). Over the 12-month follow-up period, those who received WL+EX demonstrated greater weight regain (5.2 kg; 95% CI: 3.5-6.9) relative to WL+SL (2.4 kg; 95% CI: 0.8-4.0).

CONCLUSIONS

Pairing dietary WL with a recommendation to accumulate physical activity contributed to similar WL and less weight regain compared with traditional aerobic exercise.

Precision Medicine and Obesity

Obesity is a chronic, relapsing, and multifactorial disease, with a rising prevalence and an associated high economic burden. Achieving successful and sustained weight loss outcomes with current interventions is challenging. This is due, at least in part, to the disease's heterogenous pathophysiology that is yet to be completely understood. Technological advances and greater capabilities for the extraction and storage of information have facilitated the application of precision medicine. Several precision medicine initiatives have been proposed to improve obesity outcomes. Most of these initiatives are based on -omics technologies. Although the data generated from these technologies have led to developing hypotheses that may explain the underpinnings of obesity, their applicability to the clinical practice is yet to be determined. There are other initiatives that have identified quantitative or qualitative physiologic traits that can be targeted and that could have a more immediate clinical impact. This review aims to provide a perspective of current initiatives for precision medicine for obesity.

Fat-Free Mass and Total Daily Energy Expenditure Estimated using Doubly Labelled Water Predict Energy Intake in a Large Sample of Community-Dwelling Older Adults

BACKGROUND

Up to 30% of community-based older adults report reduced appetite and energy intake (EI), but previous research examining the underlying physiological mechanisms have focused on the mechanisms that suppress eating rather than the hunger drive and EI.

OBJECTIVE

To examine the associations between fat-free mass (FFM), physical activity (PA), total daily energy expenditure (TDEE) and self-reported EI in older adults.

METHODS

The present study was a secondary analysis of The Interactive Diet and Activity Tracking in AARP Study. Body composition (deuterium dilution), PA (accelerometry) and TDEE (doubly labelled water) were measured in 590 older adults (age = 63.1 ± 5.9 years; BMI = 28.1 ± 4.9 kg/m2). Total daily EI was estimated from a single 24-hour dietary recall (EIsingle; ± one month of PA and TDEE measurement) and the mean of up to six recalls over a 12-month period (EImean), with mis-reporters classified using the 95% confidence intervals between EImean and TDEE.

RESULTS

After controlling for age and sex, linear regression demonstrated that FFM and TDEE predicted EI when estimated from a single 24-hour dietary recall (p < 0.05), the mean of up to six dietary recalls (p < 0.05) and after the removal of those classified as under-reporters (p < 0.001). Age moderated the associations between FFM and EIsingle (p < 0.001), FFM and EImean (p < 0.001), and TDEE with EIsingle (p = 0.016), with associations becoming weaker across age quintiles.

CONCLUSIONS

These data suggest that total daily EI is proportional to FFM and TDEE, but not fat mass, in older adults. These associations may reflect an underling drive to eat that influences daily food intake. While the associations between FFM or TDEE and EI existed across all age quintiles, these associations weakened with increasing age.

TRIAL REGISTRATION

The Interactive Diet and Activity Tracking in AARP (IDATA) Study was registered at clinicaltrials.gov as: NCT03268577 (http://www.clinicaltrials.gov).

Improving Gander Reproductive Efficacy in the Context of Globally Sustainable Goose Production

The goose is a popular poultry species, and in the past two decades the goose industry has become highly profitable across the globe. Ganders low reproductive performance remains a barrier to achieving high fertility and hatchability in subsequent flocks. To address the global demand for cheaper animal protein, various methodologies for improving avian (re)production should be explored. A large amount of literature is available on reproduction traits and techniques for commercial chicken breeder flocks, while research on improved reproduction in ganders has been carried out to a lesser extent. The present review aims to provide a comprehensive literature overview focusing on recent advancements/techniques used in improving gander reproductive efficacy in the context of ensuring a globally sustainable goose industry.

Postprandial glycine as a biomarker of satiety: A dose-rising randomised control trial of whey protein in overweight women

This study aimed to identify biomarkers of appetite response, modelled using a dose-rising whey protein preload intervention. Female participants (n = 24) with body mass index (BMI) between 23 and 40 kg/m² consumed preload beverages (0 g protein water control, WC; 12.5 g low-dose protein, LP; or 50.0 g high-dose protein, HP) after an overnight fast, in a randomised cross over design. Repeated venous blood samples were collected to measure plasma biomarkers of appetite response, including glucose, glucoregulatory peptides, gut peptides, and amino acids (AAs). Appetite was assessed using Visual Analogue Scales (VAS) and ad libitum energy intake (EI). Dose-rising protein beverage significantly changed the postprandial trajectory of almost all biomarkers (treatment*time, p < 0.05), but did not suppress postprandial appetite (treatment*time, p > 0.05) or EI (ANOVA, p = 0.799). Circulating glycine had the strongest association with appetite response. Higher area under the curve (AUC_0-240) glycine was associated with lower EI (p = 0.026, trend). Furthermore, circulating glycine was associated with decreased Hunger in all treatment groups, whereas the associations of glucose, alanine and amylin with appetite were dependent on treatment groups. Multivariate models, incorporating multiple biomarkers, improved the estimation of appetite response (marginal R², range: 0.13-0.43). In conclusion, whilst glycine, both alone and within a multivariate model, can estimate appetite response to both water and whey protein beverage consumption, a large proportion of variance in appetite response remains unexplained. Most biomarkers, when assessed in isolation, are poor predictors of appetite response, and likely of utility only in combination with VAS and EI.

Breakfast Consumption Suppresses Appetite but Does Not Increase Daily Energy Intake or Physical Activity Energy Expenditure When Compared with Breakfast Omission in Adolescent Girls Who Habitually Skip Breakfast: A 7-Day Randomised Crossover Trial

With concerns that adolescent girls often skip breakfast, this study compared the effects of breakfast consumption versus breakfast omission on free-living physical activity (PA) energy expenditure (PAEE) and dietary intakes among adolescent girls classified as habitual breakfast skippers. The participants went through two 7-day conditions in a trial with a crossover design: daily standardised breakfast consumption (energy content: 25% of resting metabolic rate) before 09:00 (BC) and daily breakfast omission (no energy-providing nutrients consumed) until 10:30 (BO). Free-living PAEE, dietary intakes, and perceived appetite, tiredness, and energy levels were assessed. Analyses were linear mixed models. Breakfast manipulation did not affect PAEE or PA duration. Daily fibre intake was higher (p = 0.005; d = 1.31), daily protein intake tended to be higher (p = 0.092; d = 0.54), post-10:30 carbohydrate intake tended to be lower (p = 0.096; d = 0.41), and pre-10:30 hunger and fullness were lower and higher, respectively (p ≤ 0.065; d = 0.33-1.01), in BC versus BO. No other between-condition differences were found. Breakfast-skipping adolescent girls do not compensate for an imbalance in energy intake caused by breakfast consumption versus omission through subsequent changes in PAEE but may increase their carbohydrate intakes later in the day to partially compensate for breakfast omission. Furthermore, breakfast can make substantial contributions to daily fibre intake among adolescent girls.

Jabuticaba juice improves postprandial glucagon-like peptide-1 and antioxidant status in healthy adults: a randomized crossover trial

Jabuticaba is a Brazilian berry rich in polyphenols, which may exert beneficial effects on metabolic diseases. This randomized crossover study aimed to determine the effects of jabuticaba juice (250 ml in a portion) on postprandial response. Sixteen healthy subjects (11 women; 5 men; 28.4 ± 3.8 years old; body mass index (BMI) 21.7 ± 2.3 kg m-2) consumed two test products after fasting overnight in a randomized controlled crossover design. Each test product portion had a similar composition of sugar components: 250 mL water with glucose, fructose, colored with artificial non-caloric food colorings (placebo); and 250 mL of jabuticaba juice. Beverages were administered immediately before a carbohydrate meal. Blood samples were collected at 0, 15, 30, 45, 60, 90, and 120 min after each test product to analyze the concentrations of glucose, insulin, C-peptide, antioxidant capacity, plasma glucagon-like peptide-1 (GLP-1), and appetite sensations. Compared to the placebo, the intake of jabuticaba juice resulted in a higher GLP-1 response as the area under the curve (AUC) and peaking at 60 min. Jabuticaba juice also resulted in higher antioxidant capacity. Postprandial glucose, insulin, C-peptide levels, and appetite sensations were not significantly different between tests. In conclusion, 250 mL of jabuticaba juice before a carbohydrate meal was able to improve the antioxidant status and GLP-1 concentrations in healthy subjects.

[Energy exchange: how we can personalize obesity therapy]

Obesity is a consequence of chronic energy imbalance when energy intake constantly exceeds expenditure, which leads to excess white adipose tissue accumulation. Effective treatment of obesity requires accurate measure of calories intake and expenditure, as well as related behavior to understand how energy homeostasis is regulated and evaluate the effectiveness of the measures taken. The greatest interest is to study features of energy metabolism in various forms of obesity. It is necessary to create an evidence-based, personalized approach to diet therapy and to increase the effectiveness of weight loss measures. Modern studies have shown that the use of indirect calorimetry in obesity treatment programs leads to greater weight loss compared to traditional diet therapy planning based on calculated formulas.

Is Energy Expenditure or Physical Activity Considered When Energy Intake Is Measured? A Scoping Review 1975-2015

The health-transitions humans have delivered during the 20th Century associated with the nutrition is that from undernutrition to obesity, which perseveres in the current years of the 21st Century. Energy intake (EI) is a contributing factor and therefore a fascination in nutritional sciences. However, energy expenditure (EE) has not been usually considered as a conjoint factor. Thus, this study aimed to review if studies on adults consider data on dietary intake, specifically EI, and included data on EE and physical activity (PA). A search of MEDLINE from 1975 to December 2015 was managed. Our scoping review consisted of keywords related to EI, dietary allowances, and nutritional requirements. From 2229 acknowledged articles, 698 articles were finally taken fulfilling inclusion and quality criteria. A total of 2,081,824 adults (53.7% females) were involved, and most studies had been conducted in EEUU (241), Canada (42), Australia (30), Japan (32), and Brazil (14). In Europe, apart from UK (64), the Netherlands (31) and France (26) led the classification, followed by Sweden (18), Denmark (17), and France (26). Mediterranean countries are represented with 27 studies. A total of 76.4% did not include EE and 93.1% did not include PA. Only 23.6% of the studies contained both EI and EE. A large methodological diversity was perceived, with more than 14 different methods regarding EI, and more than 10 for EE. PA was only analyzed in scarce articles, and scarcely considered for interpretation of data and conclusions. Moreover, PA was often measured by subjective questionnaires. Dietary surveys show a large diversity regarding methodology, which makes comparability of studies difficult. EE and PA are missing in around 80% of studies or are not included in the interpretation of results. Conclusions regarding EI or diet adequacy in adults should not be taken without analyzing EE and PA.

Obesity and responsibility: Is it time to rethink agency?

Despite obesity declared a disease, there still exists considerable weight stigma in both popular culture and health care, which negatively impacts policy making regarding prevention and treatment. While viewed as a choice or a failure of willpower by many, evidence exists to challenge the argument that both weight gain and failure to achieve weight loss maintenance are the individuals' fault due to personal failure or lack of responsibility. In this article, we draw upon literature from obesity treatment, neuroscience, philosophy of mind, and weight stigma to challenge the commonly held beliefs that individuals are free to choose how much they can weigh, and achievement of long-term weight loss maintenance is completely subject to conscious choice. In reality, the regulation of hunger, satiety, energy balance, and body weight takes place in subcortical regions of the brain. Thus, hunger and satiety signals are generated in regions of the brain, which are not associated with conscious experience. This points towards biological determinism of weight and challenges ideas of willpower and resultant moralization regarding body weight regulation. In this article, we will thus argue that in the context of dysregulation of hunger and satiety contributing to the obesity epidemic, a wider discourse related to personal responsibility and the stigma of obesity is needed to enhance understanding, prevention, and treatment of this complex disease. Obesity is a chronic disease requiring personalized treatment. Lifestyle interventions alone may not be enough to achieve medically significant and sustained weight loss for many individuals with obesity. By understanding that obesity is not due to a lack of motivation or willpower, the availability and utilization of additional treatments or combination of treatments such as lifestyle, pharmacotherapy, and surgery are likely to improve the quality of life for many suffering with this disease.

Perinatal Nutritional and Metabolic Pathways: Early Origins of Chronic Lung Diseases

Lung development is not completed at birth, but expands beyond infancy, rendering the lung highly susceptible to injury. Exposure to various influences during a critical window of organ growth can interfere with the finely-tuned process of development and induce pathological processes with aberrant alveolarization and long-term structural and functional sequelae. This concept of developmental origins of chronic disease has been coined as perinatal programming. Some adverse perinatal factors, including prematurity along with respiratory support, are well-recognized to induce bronchopulmonary dysplasia (BPD), a neonatal chronic lung disease that is characterized by arrest of alveolar and microvascular formation as well as lung matrix remodeling. While the pathogenesis of various experimental models focus on oxygen toxicity, mechanical ventilation and inflammation, the role of nutrition before and after birth remain poorly investigated. There is accumulating clinical and experimental evidence that intrauterine growth restriction (IUGR) as a consequence of limited nutritive supply due to placental insufficiency or maternal malnutrition is a major risk factor for BPD and impaired lung function later in life. In contrast, a surplus of nutrition with perinatal maternal obesity, accelerated postnatal weight gain and early childhood obesity is associated with wheezing and adverse clinical course of chronic lung diseases, such as asthma. While the link between perinatal nutrition and lung health has been described, the underlying mechanisms remain poorly understood. There are initial data showing that inflammatory and nutrient sensing processes are involved in programming of alveolarization, pulmonary angiogenesis, and composition of extracellular matrix. Here, we provide a comprehensive overview of the current knowledge regarding the impact of perinatal metabolism and nutrition on the lung and beyond the cardiopulmonary system as well as possible mechanisms determining the individual susceptibility to CLD early in life. We aim to emphasize the importance of unraveling the mechanisms of perinatal metabolic programming to develop novel preventive and therapeutic avenues.

Do Hot Executive Functions Relate to BMI and Body Composition in School Age Children?

Deficits of 'hot' executive functions (EFs) involving emotional and motivational processes are considered as a risk factor for excessive weight, but few studies have tested the relationship between hot EFs and body composition in children. The aim of the study was to assess the association of the ability to delay gratification and affective decision-making with the body mass index (BMI) and body composition in children with typical neurocognitive development. The sample consisted of 553 Polish children aged between 6-12 y. The delay of gratification task (DGT) was applied to assess the ability to delay gratification. The Hungry Donkey test (HDT) was applied to assess affective decision-making. The indicators of decision-making in the HDT were net score and learning rate. The relationships between hot EFs and BMI, fat mass index (FMI), lean body mass index (LBMI) were tested. The association of the z scores of BMI and FMI, overweight/obesity, and the ability to delay gratification was found insignificant after controlling cofounding factors. Most of the results on affective decision-making and z scores for BMI, FMI and LBMI were insignificant as well. The relationship between the ability to delay gratification, affective decision-making, and adiposity is not pronounced in typically developed children.

Impairment of testes development in Yangzhou ganders by augmentation of leptin receptor signaling

The aim of this study was to determine the cellular and molecular mechanisms of leptin (LEP) and the leptin receptor (LEPR) in testicular development of prepubertal ganders. In an in vivo animal experiment, active immunization against LEPR severely depressed prepubertal testicular development by significantly reducing testicular weights at 200 and 227 days of age. The number of elongated spermatids in the seminiferous tubules was also significantly decreased by immunization with LEPR at ages of 200 and 227 days. Inhibition of testicular development by LEPR immunization was associated with decreases in LHR, StAR, 3β-HSD, CYP11A1, CYP17A1, and PRLR mRNA expression levels in testicular tissue, which resulted in a significant decrease in testosterone synthesis. In the in vitro experiments, the addition of LEP combined with anti-LEPR antibodies strengthened LEPR signal transduction, and inhibited significantly testosterone production in cultured Leydig cells isolated from prepubertal gander testes. The mRNA expression of LHR, StAR, 3β-HSD, CYP11A1, CYP17A1 also decreased significantly after treatment with LEP combined with anti-LEPR antibodies in cultured Leydig cells. These results suggest that anti-LEPR antibodies strengthen LEPR signaling transduction in the presence of LEP, and immunization against LEPR inhibited testes development and testosterone secretion in prepubertal ganders.