Low calorie dieting increases cortisol

Assessing the risk of low energy availability, bone mineral density and psychological strain in endurance athletes

BACKGROUND

Adequate energy intake is crucial for athletic performance and recovery. However, many endurance athletes experience Low Energy Availability (LEA), which, if prolonged, can detrimentally impact both health and performance.

METHODS

A total of 55 endurance athletes (23 females; 45  ±  13 years, 1.64  ±  0.06 m, 64.4  ±  11.4 kg and 32 males; 44  ±  13 years, 1.76  ±  0.18 m, 78.8  ±  9.2 kg) underwent physical assessments and completed questionnaires on dietary habits, training loads, and psychological stress. Dual-Energy X-ray Absorptiometry (DEXA) scans measured bone mineral density (BMD) in the lumbar L1-L4 spine, and body composition. Risk of LEA burnout, and psychological strain were assessed using sport-specific questionnaires.

RESULTS

Seventy-seven percent of female athletes were identified as at risk of LEA by the LEAF-Q. These females had higher body weight and fat percentage than those at low risk of LEA. Male athletes had a higher prevalence of low lumbar BMD (31%) compared to females, associated with older age, and longer training histories. Although only 9% of female athletes had low-BMD, those affected had a history of amenorrhea and were identified as at risk of LEA by the LEAF-Q.

CONCLUSION

A high proportion of endurance athletes had low-BMD and were at risk of LEA. This underscores the need for targeted nutritional strategies to mitigate the risks associated with LEA and promote overall athlete well-being.

Mindfulness-based interventions for adults with type 2 diabetes mellitus: A systematic review and meta-analysis

Background

Type 2 diabetes mellitus (T2DM) can lead to macro- and microvascular complications. Mindfulness-based interventions (MBIs) may improve metabolic and psychological health in individuals with T2DM. We aimed to assess the efficacy of MBIs for management of T2DM.

Methods

We searched five databases and two trial registries using a comprehensive search strategy developed by a multidisciplinary team including an information scientist. We included randomised controlled trials (RCTs) investigating MBIs for important clinical outcomes including psychological outcomes, quality of life, glycaemic control and cardiovascular risk factors in adults with T2DM. Where possible, random effects meta-analyses were conducted. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to assess certainty of the evidence.

Results

We included 31 RCTs (2337 participants: 1107 intervention, 1230 control). We found very low certainty evidence that MBIs may reduce stress (standardized mean difference (SMD) -1.01, confidence interval (CI) -1.91 to -0.20, 8 trials, n = 528), depression (SMD -1.26, CI -2.08 to -0.43; 7 trials, n = 570) and anxiety (SMD -0.67, CI -1.27 to -0.08; 4 studies, n = 255) at end of treatment compared to waitlist control/usual care. MBIs may have a small effect on HbA1c and systolic/diastolic blood pressure at end of treatment compared to waitlist control/usual care (HbA1c mean difference (MD) -0.44, 95 % CI -0.71 to -0.17, 9 trials, n = 734; low certainty evidence). There was very low certainty evidence that MBIs + lifestyle may have no effect on HbA1c or body weight compared to lifestyle alone.

Conclusion

MBIs may have clinical benefits (particularly psychological) for adults with T2DM, but lack of certainty in the evidence precludes clinical recommendations.

Protocol registration

Cochrane Database of Systematic Reviews, DOI: 10.1002/14651858.CD014881.

Cortisol and Catecholamine Concentrations Are Affected by Repeated Relocations of Adult Female Rhesus Monkeys (Macaca mulatta)

In captive primate facilities, relocations-moves, within the facility, from one cage to another-can be common events. On the one hand, relocations are generally regarded as relatively benign events, as past studies have generally shown only transient elevations in cortisol concentrations following relocation. On the other hand, the frequency of relocations has been associated with adverse health and behavioral outcomes. As part of a larger project examining the effects of stress on follicular development, we relocated adult female rhesus monkeys on a weekly basis for several months in each of 3 years, and measured concentrations of urinary cortisol, epinephrine, and norepinephrine, as well as hair cortisol. Results for urinary cortisol and epinephrine were similar: significant elevations immediately following initiation of relocations during Years 1 and 3, and reductions in concentrations by the end of the relocation sequences in Year 1. No changes were seen for these two measures in Year 2. In contrast, elevated norepinephrine concentrations were found for all 3 years. Significant elevations in hair cortisol concentrations were found for Years 2 and 3, and suggested persisting and cumulative effects of relocations on the hypothalamic-pituitary-adrenal axis. Together, these results suggest that relocations may not be the benign events suggested by earlier studies. Given that all organs of the body are innervated by the sympathetic nervous system (the principal source of norepinephrine in blood and urine) and that cells of the body have glucocorticoid and catecholamine receptors, our results suggest possible mechanisms by which repeated relocations may result in adverse health outcomes. Repeated relocations may be a valuable model for experimentally generating moderate stress; however, we encourage colony managers and scientists to minimize such events to enhance the welfare of the animals.

The Interplay Between Psychological and Neurobiological Predictors of Weight Regain: A Narrative Review

Introduction: Obesity is a global health problem requiring effective interventions to achieve weight loss and maintain it in the long term. A major challenge for clinicians is weight regain (WR), defined as progressive weight gain following successful weight loss. WR is affected by multiple factors, including psychological traits linked to specific brain alterations. Understanding these mechanisms is crucial in developing strategies to prevent WR and to ensure effective weight control. Objectives: This narrative review aims to gather current findings on the psychological and neurobiological determinants of WR and to discuss the interplay between these factors. Methods: A literature search was conducted on PubMed, Medline, and Web of Science for English-language studies published between December 1990 and November 2024. Results: WR is driven by interconnected psychological and neurobiological factors that influence eating behavior and the regulation of body weight. Certain personality traits and emotional patterns are associated with specific changes in brain activity, which together affect vulnerability to WR. Although distinct mechanisms can be identified, the complexity of homeostatic and nonhomeostatic appetite control suggests that no single factor predominates. Conclusions: This review highlights the dynamic interplay between psychological and neurobiological predictors of WR. However, due to the narrative nature of this review, the focus on selected determinants, and the limited quality and size of the available studies, further research is needed to comprehensively understand causality and to improve relapse prevention strategies.

The Effects of Weight Loss and Aerobic Exercise on Cortisol and Cortisol Suppression in Postmenopausal Women with Overweight and Obesity

PURPOSE

The goal of this study was to explore the complex relationship between obesity, dietary content, weight loss, and cortisol concentrations in postmenopausal women with overweight and obesity.

METHODS

Women completed basal cortisol testing, a dexamethasone suppression test (DST), DXA scan, 3-hour oral glucose tolerance test (OGTT), and food records before (n = 60) and a subset after 6-months of weight loss (WL; n = 15) or aerobic exercise training+weight loss (AEX+WL, n = 34).

RESULTS

At baseline, plasma cortisol concentrations decreased significantly after DST in the entire group, a 54% suppression which was associated with basal glucose. Basal glucose levels and glucose AUC from the OGTT are associated with basal cortisol levels (r = 0.44 and r = 0.29, p < 0.05 respectively). The intervention resulted in significant weight loss (-8%) but no significant changes in basal cortisol or changes in cortisol from basal to DST were observed.

CONCLUSION

Additional research is necessary to better comprehend cortisol regulation in postmenopausal women particularly in response to effective weight reduction interventions.

Effects of Quercetin Metabolites on Glucose-Dependent Lipid Accumulation in 3T3-L1 Adipocytes

The aim of the study was to assess the effects of quercetin metabolites (QMs) on lipid accumulation in adipocytes under high-glucose and physiological-glucose concentrations and to elucidate the mechanisms involved. 3T3-L1 mature adipocytes were exposed to a physiological glucose concentration, as a model of caloric restriction (CR), or high glucose (control), with and without QMs (quercetin-3-glucuronide [Q3G] and isorhamnetin [ISOR]). Cells were treated with Q3G (0.3 and 0.6 µmol/L) and ISOR (0.2 and 0.4 µmol/L) for 48 h. Lipid accumulation (Oil Red O staining) and Δ glucose level (HPLC) were assessed. Under high glucose, Q3G and ISOR reduced lipid accumulation (-10.8% and -10.4%; p < 0.01) and Δ glucose level (-13.6% and -14.2%; p < 0.05). Under CR, QMs increased Δ glucose level (+21.6% for Q3G and +21% for ISOR; p < 0.05). ISOR increased pAMPK levels under high glucose (+1.4-fold; p < 0.05). Under CR, Q3G and ISOR increased pAMPK (+1.4- and +1.5-fold; p < 0.05), while ISOR upregulated SIRT1 and PGC-1α (+2.3- and +1.5-fold; p < 0.05). Findings support, for the first time, the potential contribution of QMs, especially ISOR, in the regulation of lipid metabolism in vitro, possibly via AMPK activation. Further studies, including in vivo, are encouraged to strengthen evidence of the mechanisms observed.

Bracing for impact: An intensive longitudinal investigation of weight stigma, vigilant coping, and maladaptive eating

OBJECTIVE

Interpersonal weight stigma (being teased, treated unfairly, or discriminated against for body weight) increases one's stress and negatively impacts their well-being. Weight stigma consistently increases maladaptive eating behaviors, such as eating to cope, binge eating, and restrictive dieting. Previously published cross-sectional models suggest that vigilant coping (being on the lookout for future discrimination) is one way in which weight stigma may impact maladaptive eating behaviors, especially as internalized weight stigma (self-stigma) increases. This study aimed to analyze these relationships longitudinally using ecological momentary assessments.

METHODS

Female, higher weight college students (MBMI = 32.7, SDBMI = 6.09) from a large public midwestern university (N = 130) completed 3 surveys per day for 7 days, reporting their vigilant coping, eating to cope, restrictive dieting, and binge eating. Data was collected from January 2023-February 2024. We examined the relationship between baseline experienced and internalized weight stigma and day-to-day vigilant coping. Additionally, we examined vigilant coping earlier in the day as a predictor of eating later in the day.

RESULTS

Experienced and internalized weight stigma did not interact to predict day-to-day vigilant coping, but they both independently predicted vigilant coping. Vigilant coping earlier in the day predicted restrictive dieting later in the day but did not predict emotional or binge eating. There were no significant conditional indirect effects.

CONCLUSIONS

This study establishes vigilant coping as a longitudinal predictor of restrictive dieting, but further research is required to understand other health behaviors and outcomes related to vigilant coping.

Relationships Between Body Image and Body Parameters in Men Under Long-Term Fasting Conditions

Background/Objectives: Fasting and physical exertion positively affect body mass and composition. This study aimed to examine the effects of physical changes induced by eight days of water-only fasting and a physical exertion test and their influence on body satisfaction and body image parameters in middle-aged men. Methods: Fifteen participants were assessed for physical (height, body mass, and body composition) and psychological (body satisfaction, evaluation of body parts, and body image determinants) aspects before and after the fasting intervention, both at rest and post-exercise. Correlation and concordance coefficients were calculated for the analyzed variables. Results: It was found that the fasting intervention led to a reduction in body mass and a favorable shift in body composition, while also increasing satisfaction with one's body and its specific parts. This positively impacted volunteers' self-assessment of their health status. Selected body image parameters remained at an average level for the male population and did not change following the fasting. Attitudes toward body weight control methods and their perceived effectiveness did not change either. Participants favored reducing food intake and eliminating high-calorie products from their diet, rejecting the use pathological methods typically associated with eating disorders. A few associations between physical and psychological aspects of corporeality were observed, whereas significant correlations between satisfaction with body parts and parameters and a positive body image were confirmed. Conclusions: The above suggest that physical conditions and their changes resulting from fasting and physical exertion lead to a positive influence on body satisfaction and its components but do not alter body image.

Investigating Cortisol in a STEM Classroom: The Association Between Cortisol and Academic Performance

Science, technology, engineering, and mathematics (STEM) education can be stressful, but uncertainty exists about (a) whether stressful academic settings elevate cortisol, particularly among students from underrepresented racial/ethnic groups, and (b) whether cortisol responses are associated with academic performance. In four classes around the first exam in a gateway college STEM course, we investigated participants' (N = 271) cortisol levels as a function of race/ethnicity and tested whether cortisol responses predicted students' performance. Regardless of race/ethnicity, students' cortisol, on average, declined from the beginning to the end of each class and across the four classes. Among underrepresented minority (URM) students, higher cortisol responses predicted better performance and a lower likelihood of dropping the course. Among non-URM students, there were no such associations. For URM students, lower cortisol responses may have indicated disengagement, whereas higher cortisol responses may have indicated striving. The implication of cortisol responses can depend on how members of a group experience an environment.

How do BMI-restrictive policies impact women seeking NHS-funded IVF in the United Kingdom? A qualitative analysis of online forum discussions

BACKGROUND

Across the United Kingdom's National Health Service (NHS), women with a Body Mass Index (BMI) of > 30 face restrictions accessing In Vitro Fertilisation (IVF) treatment. This study asks: what are the (un)expected and (un)intended harms and consequences experienced by women restricted from accessing NHS-funded IVF due to BMI threshold criteria?

METHODS

Posts from a popular infertility online forum were collected and reflexively thematically analysed.

RESULTS

On the forum, users discussed how they struggled to lose weight, how they faced time pressures to meet BMI thresholds, and they shared knowledge on how to comply or appear compliant with BMI cut-offs. Our study found widespread moral discourses around body weight were reproduced in the forum, particularly commonplace narratives that body weight is under personal control, that people with a high BMI should 'work' to change their bodies, and that this work helps demonstrate deservingness for IVF treatment. Moralising discourses around weight were linked to the responsibilities of a hoped-for future of motherhood, as users performed deservingness through emphasising their commitment to meeting the BMI threshold.

CONCLUSION

We conclude that NHS-IVF policies in the United Kingdom do not consider the burdensome emotional and moral work placed on people seeking treatment due to inflexible upper-limit BMI criteria.

GLP-1 agonists and risk of suicidal thoughts and behaviours: Confound by indication once again? A narrative review

Glucagon-like peptide-1 (GLP-1) agonists have been successfully used in clinical practice for the treatment of diabetes and obesity, offering significant clinical benefits. However, concerns regarding their potential link to psychiatric side effects, like suicidal thoughts and behaviours (STB) have emerged. This narrative review investigates the complex interplay between GLP-1 agonists and STB, focusing on the biological stress induced by rapid weight loss, psychological and social consequences, similar mechanism with addiction, and the evaluative lens of the Bradford Hill criteria on causality. While GLP-1 agonists can contribute to substantial health improvements, they also introduce biological and psychological stressors. Disruptions in homeostasis from quick weight reduction can elevate cortisol and norepinephrine levels, heightening the risk for, or exacerbation of STB. Psychological factors, including unfulfilled expectations and identity changes after significant weight loss, compound these risks. Utilizing the Bradford Hill criteria reveals insufficient evidence for a direct causal link between GLP-1 agonists and STB. Yet, the indirect effects related to the metabolic and psychological disturbances associated with rapid weight loss call for a cautious approach. Used carefully in targeted populations GLP-1 agonists may even emerge as protective agents against STB. Therefore, it is crucial to monitor patients during the treatment and screen for preexisting mental health conditions. If detected, appropriate clinical management should be applied. Future studies should aim at optimizing dosing schedules to mitigate the adverse effects of rapid weight loss and further investigate GLP-1 agonists in possible STB prevention.

Pre-Surgery Cortisol Levels as Biomarker of Evolution after Bariatric Surgery: Weight Loss and Weight Regain

Background: Bariatric surgery (BS) is effective for achieving significant weight loss. However, weight regain (WR) is an emerging problem. Objective: To assess the prognostic value of morning serum cortisol, a 1 mg dexamethasone suppression test (DST), 24 h urinary free cortisol (UFC) and late-night salivary cortisol (LNSC) in a cohort of patients with severe obesity (pwSO) undergoing BS in terms of weight loss and WR. Methods: Patients scheduled for BS underwent the following procedures at baseline, 12 months and 24 months after BS: medical history, anthropometric data, blood analysis and cortisol tests. We evaluated total weight loss (TWL) ≥ 30% at 1 year and WR after 2 years as an increase of ≥10% of the maximum weight lost. Results: In total, 142 subjects were included; 101 (71.1%) were females and the mean age was 45.9 ± 9.2 years. Up to 76.8% of subjects achieved ≥30% TWL, without statistically significant differences in DST results or morning serum cortisol, UFC or LNSC levels. However, a higher pre-surgery morning serum cortisol level was a significant predictor of a WR ≥ 10% (cortisol 17.8 [IQR 13.1-18.5] vs. 12.0 [IQR 8.8-15.8] μg/dL; p < 0.01); OR of 1.216 (95% CI 1.069-1.384); AUC [0.761, CI: (0.616-0.906); p < 0.01]. A cut-off value of cortisol > 13.0 μg/dL was predictive of a WR ≥ 10% (sensitivity 0.71; specificity 0.63). Conclusions: No cortisol test was useful in predicting weight loss; however, the pre-surgery morning serum cortisol level was able to predict a WR ≥ 10% in a cohort of pwSO 2 years after BS. A cut-off value of cortisol > 13 μg/dL might be an easy tool to identify patients at higher risk of WR, enabling healthcare providers to implement tailored, long-term strategies to minimize this outcome.

A systematic review of observational studies exploring the relationship between health and non-weight-centric eating behaviours

Eating behaviour that does not centralise weight, otherwise known as weight-neutral, is associated with improved physical and psychological health, and greater health promoting behaviours. However, consolidated evidence is lacking. This study aimed to systematically evaluate 'health-centric' eating behaviour reflective of weight-neutral approaches, and their relationship with health (physical and mental) and health promoting behaviours. A systematic search was performed, identifying observational studies with adult populations, ≥1 physical/mental health outcome(s), and ≥1 validated measure(s) of health-centric eating behaviour. Study design, sample characteristics and outcomes were extracted and characterised into four domains. Our search identified 8281 records, with 86 studies, 75 unique datasets, and 78 unique exposures including 94,710 individuals. Eating behaviours included intuitive eating (n = 48), mindful eating (n = 19), and eating competence (n = 11). There were 298 outcomes identified for body composition, size, and physical health (n = 116), mental health and wellbeing (n = 123), health promoting behaviours (n = 51) and other eating behaviour (n = 8). Higher levels of intuitive eating, mindful eating and eating competence were significantly related to a lower BMI, better diet quality and greater physical activity. Higher intuitive and mindful eating were significantly related to lower levels of disordered eating, and depressive symptoms, and greater body image, self-compassion, and mindfulness. Greater eating competence and intuitive eating were significantly related to higher fruit and vegetable intake, and greater eating competence to higher fibre intake and better sleep quality. Our results demonstrate that 'health-centric' eating behaviours are related to a range of favourable health outcomes and engagement in health promoting behaviours. These findings help to enhance our understanding of eating behaviours that do not centre around body weight, providing support for health-centric eating behaviour in healthcare. Future research should focus on intervention studies and more diverse population groups.

Physiological, body composition, and body mass measures show that a developmental measure of weight suppression is more valid than the traditional measure

OBJECTIVE

The traditional measure of weight suppression (TWS; the difference between an individual's highest past weight at adult height and current weight), has been associated with many psychological, behavioral and biological variables in those with eating disorders. A new measure of weight suppression, called developmental weight suppression (DWS), corrects two major problems in the original measure. Initial research indicates that DWS represents a superior operationalization of the construct weight suppression was originally designed to measure (Lowe [1993, Psychol Bull, 114: 100]). This study is the first to examine the relation between both WS measures and weight history, body composition and a variety of metabolic hormones.

METHODS

Data were collected in 91 women with bulimia nervosa (BN) or BN-spectrum disorders.

RESULTS

Both weight suppression indices were related to multiple hormones. However, multiple regression analyses showed that the independent effects of DWS differed from the independent effects of TWS in that only DWS was negatively related to: (1) current z-BMI, (2) body fat percentage, and (3) insulin, leptin, T3 free, and TSH. This differential pattern also occurred when results were corrected for multiple comparisons.

DISCUSSION

Findings provide stronger biological support for the construct validity of DWS than TWS and suggest that: (1) from the perspective of individuals with BN, high DWS embodies success at food restriction and weight loss, (2) elevated DWS may trap individuals with BN in a powerful biobehavioral bind, and (3) DWS is the preferred measure of weight suppression in future research on eating disorders.

PUBLIC SIGNIFICANCE

Most individuals with bulimia nervosa lose substantial weight in the process of developing their disorder. Such weight suppression is related to many characteristics of those with the eating disorder bulimia nervosa. This study shows why a new measure of weight suppression, based on an individual's growth during development, is more biologically valid than the traditional measure of weight suppression.

Food insecurity, poor diet, and metabolic measures: The roles of stress and cortisol

Food insecurity is highly prevalent and linked to poorer diet and worse metabolic outcomes. Food insecurity can be stressful, and could elicit chronic psychological and physiological stress. In this study, we tested whether stress could be used to identify those at highest risk for worse diet and metabolic measures from food insecurity. Specifically, we hypothesized that cortisol (a physiological marker of stress) and perceived psychological stress would amplify the link between food insecurity and hyperpalatable food intake as well as metabolic measures. In a sample of 624 Black and White women aged 36-43 who participated in the NHLBI Growth and Health Study's midlife assessment, we assessed associations between food insecurity with hyperpalatable food intake (high fat + high sodium foods; high fat + high sugar foods; and high carbohydrate + high sodium foods), and metabolic measures (fasting glucose, insulin resistance, and waist circumference). We found that food insecurity was associated with higher levels of perceived stress (R2 = 0.09), and greater intake of high fat + high sugar (hyperpalatable) foods (R2 = 0.03). In those with higher cumulative cortisol (as indexed by hair cortisol), food insecurity was associated with higher levels of fasting glucose. Neither cortisol nor perceived stress moderated any other relationships, and neither variable functioned as a mediator in sensitivity analyses. Given these largely null findings, further research is needed to understand the role stress plays in the chronic health burdens of food insecurity.

Prepregnancy dieting and obstetrical and neonatal outcomes: Findings from a national surveillance project in the United States

PROBLEM AND BACKGROUND

Women with overweight or obesity are recommended to lose weight before pregnancy. Dieting is one of the most used weight control strategies. However, the health implications of dieting before pregnancy remain unclear.

AIM

To evaluate the associations of dieting during the year before pregnancy with obstetrical and neonatal outcomes, including gestational weight gain (GWG), gestational diabetes, low birthweight, macrosomia, small-for-gestational-age infants (SGA), large-for-gestational-age infants (LGA), and preterm birth.

METHODS

This study analyzed data from the Pregnancy Risk Assessment Monitoring System (PRAMS), which is a surveillance project in the United States that collects data on maternal health before, during, and after pregnancy. Women who participated in PRAMS phase 7 with a prepregnancy body mass index ≥25 kg/m2 and a singleton birth were eligible. Statistical analyses included logistic regressions and post-hoc mediation analysis (Sobel Test).

FINDINGS

A total number of 51,399 women were included in the analysis. Women who self-reported prepregnancy dieting (42.8 %) had lower odds of SGA (adjusted odds ratio [aOR]: 0.87; 95 % CI: 0.79-0.97), and higher odds of excessive GWG vs adequate GWG (aOR: 1.42; 95 % CI: 1.32-1.52), gestational diabetes (aOR: 1.12; 95 % CI: 1.02-1.22), and LGA (aOR: 1.18; 95 % CI: 1.08-1.28). Furthermore, the association between prepregnancy dieting and LGA was mediated by excessive GWG (Sobel Test z-value = 5.72, p < 0.01).

DISCUSSION AND CONCLUSION

This analysis revealed that prepregnancy dieting was associated with several adverse consequences, including excessive GWG, gestational diabetes, and LGA infants. Findings contribute to an improved understanding of the perinatal implications of prepregnancy dieting.

Weight Regain after Metabolic Surgery: Beyond the Surgical Failure

Patients undergoing metabolic surgery have factors ranging from anatomo-surgical, endocrine metabolic, eating patterns and physical activity, mental health and psychological factors. Some of the latter can explain the possible pathophysiological neuroendocrine, metabolic, and adaptive mechanisms that cause the high prevalence of weight regain in postbariatric patients. Even metabolic surgery has proven to be effective in reducing excess weight in patients with obesity; some of them regain weight after this intervention. In this vein, several studies have been conducted to search factors and mechanisms involved in weight regain, to stablish strategies to manage this complication by combining metabolic surgery with either lifestyle changes, behavioral therapies, pharmacotherapy, endoscopic interventions, or finally, surgical revision. The aim of this revision is to describe certain aspects and mechanisms behind weight regain after metabolic surgery, along with preventive and therapeutic strategies for this complication.

Short-duration cold exposure decreases fasting-induced glucose intolerance but has no effect on resting energy expenditure

The aim of the present study was to investigate whether brief cold exposure can reverse fasting-induced glucose intolerance and insulin resistance, and improve resting energy expenditure (REE). Twelve young non-obese women were randomly assigned to undergo the following conditions: 2 days of fasting with two 10-min whole-body cold-water immersions on separate days (FAST-COLD), 2 days of fasting without cold-water immersions (FAST), 2 days of usual diet with two 10-min whole-body cold-water immersions on separate days (COLD), or 2 days of usual diet without cold-water immersions (CON) in a randomised crossover fashion. Changes in REE and substrate utilisation, and glucose tolerance and insulin sensitivity from the oral glucose tolerance test were examined. The results showed that FAST-COLD and FAST trials increased (P < 0.05) REE and decreased (P < 0.05) respiratory quotient, but these variables did not differ significantly between the FAST-COLD and FAST trials. The glucose and insulin area under the curves (AUCs) were higher (P < 0.05) in the FAST-COLD and FAST trials than in the CON and COLD trials, and these AUCs were lower (P < 0.05) in the FAST-COLD than in the FAST trial. Matsuda index was lower in the FAST trial than in the CON trial (P < 0.05), and tended to be greater after the FAST-COLD trial than after the FAST trial (P = 0.060). In conclusion, cold exposure had no effect on REE but decreased fasting-induced glucose intolerance which was accompanied by a maintained insulin sensitivity.

Nutritional Intervention in Cushing's Disease: The Ketogenic Diet's Effects on Metabolic Comorbidities and Adrenal Steroids

BACKGROUND

a very low-calorie ketogenic diet (VLCKD) is associated with improvement of metabolic and cardiovascular disorders. We aimed to evaluate the effects of a VLCKD in patients with Cushing's disease (CD) as adjunctive therapy to treatment for the primary disease.

METHODS

we evaluated clinical, hormonal and metabolic parameters in 15 patients with CD and 15 controls at baseline after 1 week and 3 weeks of VLCKD and, further, after 2 weeks of a low-carbohydrate ketogenic diet (LCKD).

RESULTS

after 5 weeks of diet, a significant decrease in BMI (p = 0.002), waist circumference (WC) (p = 0.024), systolic blood pressure (p = 0.015), diastolic blood pressure (p = 0.005), ACTH (p = 0.026), cortisone (p = 0.025), total cholesterol (p = 0.006), LDL cholesterol (p = 0.017), triglycerides (p = 0.016) and alkaline phosphatase (p = 0.008) and a significant increase in HDL cholesterol (p = 0.017), vitamin D (p = 0.015) and oral disposition index (oDI) (p = 0.004) was observed in the CD patients. A significant decrease in BMI (p = 0.003), WC (p = 0.002), systolic blood pressure (p = 0.025), diastolic (p = 0.007) blood pressure and total cholesterol (p = 0.026) and an increase in HDL cholesterol (p = 0.001) and oDI (p < 0.001) was observed in controls.

CONCLUSIONS

the current study confirms that a ketogenic diet is effective in improving metabolic disorders in CD and shows that a nutritional approach may be combined with conventional CD therapy in order to improve metabolic and cardiovascular comorbidities.

Supplementation with a high-glucose drink stimulates anti-tumor immune responses to glioblastoma via gut microbiota modulation

A high-sugar diet induces lifestyle-associated metabolic diseases, such as obesity and diabetes, which may underlie the pro-tumor effects of a high-sugar diet. We supply GL261 syngeneic glioblastoma (GBM) mice with a short-term high-glucose drink (HGD) and find an increased survival rate with no evidence of metabolic disease. Modulation of the gut microbiota through HGD supplementation is critical for enhancing the anti-tumor immune response. Single-cell RNA sequencing shows that gut microbiota modulation by HGD supplementation increases the T cell-mediated anti-tumor immune response in GBM mice. We find that the cytotoxic CD4+ T cell population in GBM is increased due to synergy with anti-programmed cell death protein 1 (anti-PD-1) immune checkpoint inhibitors, but this effect depends upon HGD supplementation. Thus, we determine that HGD supplementation enhances anti-tumor immune responses in GBM mice through gut microbiota modulation and suggest that the role of HGD supplementation in GBM should be re-examined.

Acupuncture as multi-targeted therapy for the multifactorial disease obesity: a complex neuro-endocrine-immune interplay

The prevalence of obesity has reached pandemic dimensions. It is associated with multiple comorbidities and is becoming a clinical and public health threat. Obesity is a multifactorial disease with a complex pathophysiology and interplay of various systems. A strong interplay exists between the neuro-endocrine system, the immune system with systemic chronic low-grade inflammation, and microbiome dysbiosis that can lead to the development of obesity, which in turn can exacerbate each of these factors, hence creating a vicious cycle. The conventional treatment with lifestyle modifications such as diet, physical exercise, pharmacotherapy, and bariatric surgery does not always result in sufficient weight control thus paving the way for other strategies. As one such strategy, acupuncture is increasingly used worldwide to treat obesity. This narrative review outlines the evidence for this neuro-endocrine-immune interplay in the pathophysiology of obesity. Furthermore, the existing experimental and clinical evidence of acupuncture as a multi-targeted therapy for obesity is explained and future research perspectives are discussed.

Effects of Fasting on the Physiological and Psychological Responses in Middle-Aged Men

Tracking changes in the body during fasting takes into account indicators of mental well-being and physiological parameters. The aim of the study was to measure psychological and physiological reactions, along with their mutual relations, caused by 8 days of water-only fasting. Fourteen men aged 35 to 60 participated in the study, divided into two groups, younger and elder. In addition to physiological parameters, psychological data were collected using four different tests. The obtained results confirmed reduction in body weight, systolic blood pressure, resting diastolic blood pressure and glucose level, and increase in resting heart rate, cortisol and β-hydroxybutyrate concentration. However, no significant psychological changes were observed under the influence of fasting intervention. A significant interaction effect occurred for the state anxiety variable determined before and after the fasting intervention for both groups. Moreover, negative correlations between physiological (cortisol) and psychological factors of subjectively assessed stress were revealed. The only effect on cognitive ability was seen when responding to simple tasks. The study confirmed the beneficial effect of 8 days of water-only fasting on physiological variables without affecting mental well-being. The relatively high level of well-being after fasting intervention was independent of the physiological indicators of stress.

Maternal neglect alters reward-anticipatory behavior, social status stability, and reward circuit activation in adult male rats

Introduction

Adverse early life experiences affect neuronal growth and maturation of reward circuits that modify behavior under reward predicting conditions. Previous studies demonstrate that rats undergoing denial of expected reward in the form of maternal contact (DER-animal model of maternal neglect) during early post-natal life developed anhedonia, aggressive play-fight behaviors and aberrant prefrontal cortex structure and neurochemistry. Although many studies revealed social deficiency following early-life stress most reports focus on individual animal tasks. Thus, attention needs to be given on the social effects during group tasks in animals afflicted by early life adversity.

Methods

To investigate the potential impact of the DER experience on the manifestation of behavioral responses induced by natural rewards, we evaluated: 1) naïve adult male sexual preference and performance, and 2) anticipatory behavior during a group 2-phase food anticipation learning task composed of a context-dependent and a cue-dependent learning period.

Results

DER rats efficiently spent time in the vicinity of and initiated sexual intercourse with receptive females suggesting an intact sexual reward motivation and consummation. Interestingly, during the context-dependent phase of food anticipation training DER rats displayed a modified exploratory activity and lower overall reward-context association. Moreover, during the cue-dependent phase DER rats displayed a mild deficit in context-reward association while increased cue-dependent locomotion. Additionally, DER rats displayed unstable food access priority following food presentation. These abnormal behaviours were accompanied by overactivation of the ventral prefrontal cortex and nucleus accumbens, as assessed by pCREB levels.

Conclusions/discussion

Collectively, these data show that the neonatal DER experience resulted in adulthood in altered activation of the reward circuitry, interfered with the normal formation of context-reward associations, and disrupted normal reward access hierarchy formation. These findings provide additional evidence to the deleterious effects of early life adversity on reward system, social hierarchy formation, and brain function.

Effects of very low-calorie ketogenic diet on hypothalamic-pituitary-adrenal axis and renin-angiotensin-aldosterone system

BACKGROUND

The hypothalamic-pituitary-adrenal (HPA) axis is a neuroendocrine system involved in controlling stress responses in humans under physiological and pathological conditions; cortisol is the main hormone produced by the HPA axis. It is known that calorie restriction acts as a stressor and can lead to an increase in cortisol production. Renin-angiotensin-aldosterone system (RAAS) is a complex endocrine network regulating blood pressure and hydrosaline metabolism, whose final hormonal effector is aldosterone. RAAS activation is linked to cardiometabolic diseases, such as heart failure and obesity. Obesity has become a leading worldwide pandemic, associated with serious health outcomes. Calorie restriction represents a pivotal strategy to tackle obesity. On the other hand, it is well known that an increased activity of the HPA may favour visceral adipose tissue expansion, which may jeopardize a successful diet-induced weight loss. Very low-calorie ketogenic diet (VLCKD) is a normoprotein diet with a drastic reduction of the carbohydrate content and total calorie intake. Thanks to its sustained protein content, VLCKD is extremely effective to reduce adipose tissue while preserving lean body mass and resting metabolic rate.

PURPOSE

The purpose of this narrative review is to gain more insights on the effects of VLCKD on the HPA axis and RAAS, in different phases of weight loss and in different clinical settings.

Protein-caloric restriction induced HPA axis activation and altered the milk composition imprint metabolism of weaned rat offspring

OBJECTIVES

Maternal protein-caloric restriction during lactation can malprogram offspring into having a lean phenotype associated with metabolic dysfunction in early life and adulthood. The aim of this study was to investigate the relationships between nutritional stress, maternal behavior and metabolism, milk composition, and offspring parameters. Additionally, we focused on the role of hypothalamus-pituitary-adrenal axis hyperactivation during lactation.

METHODS

Dams were fed a low-protein diet (4% protein) during the first 2 wk of lactation or a normal-protein diet (20% protein) during all lactation. Analyses of dams, milk, and offspring were conducted on postnatal days (PD) 7, 14, and 21.

RESULTS

Body weight and food intake decreased in dams, which was associated with reduced fat pad stores and increased corticosterone levels at PD 14. The stressed low-protein diet dams demonstrated alterations in behavior and offspring care. Despite nutritional deprivation, dams adapted their metabolism to provide adequate energy supply through milk; however, we demonstrated elevated corticosterone and total fat levels in milk at PD 14. Male offspring also showed increased corticosterone at PD 7, associated with a lean phenotype and alterations in white and brown adipose tissue morphology at PD 21.

CONCLUSION

Exposure to protein-caloric restriction diet of dams during lactation increased the glucocorticoid levels in dams, milk, and offspring, which is associated with alterations in maternal behavior and milk composition. Thus, glucocorticoids and milk composition may play an important role in metabolic programming induced by maternal undernutrition.

Cooking Interventions for Improving Diet Quality Among Black Americans: A Randomized Controlled Trial

BACKGROUND

Non-Hispanic Black Americans experience the highest, and most rapidly increasing, rates of obesity. Despite evidence that this is at least somewhat related to poor diet quality, we have yet to identify effective interventions for improving diet quality long-term. Restrictive diets can be ineffective and often harmful. In contrast, there is a well-established connection between home cooking and lower body mass index, better diet quality, and improved health.

PURPOSE

The present study applied the Theory of Planned Behavior (TPB) to examine the effect of an intervention delivering cooking instruction, rather than nutrition information, on beliefs, attitudes, and behaviors pertaining to diet quality and cooking among Black adults in the USA.

METHODS

An online sample of Black Americans (N = 147), ages 18-76 (M = 30.69, SD = 10.42) were recruited via Prolific and randomized to view either a cooking tutorial video or a "standard of care" control webpage followed by either an implementation intentions (II) writing activity or a "freestyle" control writing activity. Cognitions and behavior related to healthy eating and cooking were measured at baseline, post-intervention, and 1-week follow-up.

RESULTS

Results of mixed-effects modeling indicated that participants randomized to the video condition reported significantly greater post-intervention intentions to cook (p < .001), which positively correlated with cooking behavior over the subsequent week (p < .01). There was no effect of the II intervention on subsequent-week behavior (ps > .413). Importantly, 75% (n = 105) indicated experiencing food insecurity at the time of data collection.

CONCLUSIONS

These results highlight a promising pathway for improving nutrition and diet-related health outcomes among Black Americans while highlighting that any intervention must account for food insecurity in this population.

Health and weight attitudes of university recreation center leaders

Objective: Emerging research suggests weight-neutral approaches to health promotion are effective in supporting overall health, but they have been minimally adopted within physical activity (PA) contexts. This is concerning as research shows PA-related professionals can perpetuate weight stigma, which can disrupt PA participation and enjoyment. Thus, the purpose of this study was to examine university recreation center (URC) leaders' attitudes toward health and weight. Participants and methods: One-hundred forty-one URC leaders completed the online Health and Weight Attitudes Scale. Results: Women and those who wanted to maintain weight had more positive attitudes toward not dieting than men (F (1,136)=5.090, p = 0.026, η_p² = 0.036) and those who wanted to lose weight (p = 0.015). Participants' open-ended responses showed they held several misconceptions about the health and weight relationship and about weight-neutral eating and PA messaging. Conclusion: Educating PA professionals on weight-neutral approaches could benefit effective and inclusive PA and health promotion in URCs.

Effect of Time-Restricted Feeding on Anthropometric, Metabolic, and Fitness Parameters: A Systematic Review

Time restricted feeding (TRF) as a form of intermittent fasting (IF) has gained popularity because its ability to reduce body mass (BM) without an emphasis on caloric restriction. However, how this dietary protocol may affect health, fitness, and performance in a relatively healthy cohort remains less clear. The purpose of this article was to systematically review the current literature concerning the effect of TRF on anthropometric, metabolic, and fitness parameters in normal-weight adults and overweight and obese individuals. A systematic search of English literature was conducted through databases including PubMed, CINAHL, and Google Scholar. The search was facilitated by using various combinations of key words related to nutritional interventions, i.e., IF and TRF, and outcomes of interest, i.e., BM, body composition, glucose, insulin, lipid, fitness, and performance. The article selection was made based on the inclusion and exclusion criteria concerning the participants' characteristics, study design, intervention protocols, and targeted dependent variables. Twenty-three full-text longitudinal randomized and nonrandomized controlled studies were selected for this review. Our analysis indicates that TRF can reduce BM and improve nutrient metabolism in both normal- and over-weight individuals. TRF does not appear to alter protein synthesis and fat-free mass nor hamper aerobic fitness and muscular performance among physically active individuals including athletes. In conclusion, TRF as a more easily adaptable form of IF is a promising dietary approach to improving body composition and metabolic health while maintaining fitness and muscular function. However, more research is needed before this dietary protocol can be fully recommended for athletes especially those competing in sports that demand strength and power.Key teaching points and nutritional relevanceTime-restricted feeding (TRF) differs from other fasting protocols due to its emphasis on restricting eating window rather than caloric intake and can be more easily adopted by simply skipping a meal.Its deemphasis on caloric restriction appeals to many young and physically active individuals wanting to optimize body composition but needing sufficient energy to support their physical training and daily activity.Much of what is known regarding the impact of TRF on fitness and athletic performance was derived from studies that use the Ramadan fasting protocol, which differs from TRF in terms of protocol duration and feeding schedule.This review concludes that TRF is a promising dietary approach to improving body composition and metabolic health while maintaining fitness and muscular function in both normal- and over-weight individuals.Due to limited evidence concerning TRF and athletic performance, more research is needed before this dietary protocol can be fully recommended for athletes especially those competing in sports that demand strength and power.

Withdrawal: A key consideration in evaluating whether highly processed foods are addictive

Researchers are currently debating whether theories of addiction explain compulsive overeating of highly processed (HP) foods (i.e., industrially created foods high in refined carbohydrates and/or fat), which contributes to obesity and diet-related disease. A subset of individuals consumes HP foods with behavioral phenotypes that mirror substance use disorders. Withdrawal, the emergence of aversive physical and psychological symptoms upon reduction or cessation of substance use, is a core component of addiction that was central to historical debates about other substances' addictive potential (e.g., nicotine and cocaine). However, no one has systematically considered evidence for whether HP foods cause withdrawal, which represents a key knowledge gap regarding the utility of addiction models for understanding compulsive overeating. Thus, we reviewed evidence for whether animals and humans exhibit withdrawal when reducing or eliminating HP food intake. Controlled experimental evidence indicates animals experience HP food withdrawal marked by neural reward changes and behaviors consistent with withdrawal from other addictive substances. In humans, preliminary evidence supports subjective withdrawal-like experiences. However, most current human research is limited to retrospective recall. Further experimental research is needed to evaluate this construct. We outline future research directions to investigate HP food withdrawal in humans and consider potential clinical implications.

Differential Changes in Circulating Steroid Hormones in Hibernating Brown Bears: Preliminary Conclusions and Caveats

Brown bears are obese when they enter the den, and after 6 mo of hibernation and physical inactivity, bears show none of the adverse consequences of a sedentary lifestyle in humans, such as cardiovascular disease, type 2 diabetes, and kidney failure. The metabolic mechanisms that drive hibernation physiology in bears are poorly defined, but systemic endocrine regulators are likely involved. To investigate the potential role of steroid hormones, we quantified the total levels of 12 steroid hormones, the precursor cholesterol, sex hormone-binding globulin (SHBG), and corticosterone-binding globulin (CBG) in paired serum samples from subadult free-ranging Scandinavian brown bears during the active and hibernation states. During hibernation, androstenedione and testosterone were significantly decreased in subadult female bears (n=13), whereas they increased in all males but one (n=6) and therefore did not reach a significant difference. Despite this difference, SHBG increased more than 20-fold during hibernation for all bears. Compared with SHBG concentrations in humans, bear levels were very low in the active state, but during hibernation, levels equaled high levels in humans. The increased SHBG levels likely maintain a state of relative quiescence of the reproductive hormones in hibernating bears. Interestingly, the combination of SHBG and testosterone levels results in similar free bioavailable testosterone levels of 70-80 pM in both subadult and adult sexually active male bears, suggesting a role for SHBG in controlling androgen action during hibernation in males. Dehydroepiandrosterone sulfate, dihydrotestosterone, and estradiol levels were below the detection limit in all but one animal. The metabolically active glucocorticoids were significantly higher in both sexes during hibernation, whereas the inactive metabolite cortisone was reduced and CBG was low approaching the detection limit. A potential caveat is that the glucocorticoid levels might be affected by the ketamine applied in the anesthetic mixture for hibernating bears. However, increased hibernating cortisol levels have consistently been reported in both black bears and brown bears. Thus, we suggest that high glucocorticoid activity may support the hibernation state, likely serving to promote lipolysis and gluconeogenesis while limiting tissue glucose uptake to maintain a continuous glucose supply to the brain.

Evidence of the Associations between Individual and Partner Autonomy Support and Physiological Stress in the Context of Conversations about Weight among Couples Who are Overweight or Obese during a 6-Month Intervention

The aim of the study was to examine the impact of supportive communication on acute physiological stress responses during weight-related conversations taking place throughout a couples' weight loss program. Participants were 47 married or cohabitating couples where each partner had a BMI of 25-40 kg/m². Couples were randomized as a dyad into a traditional weight loss program or a program that also included training in providing support to one's partner throughout the weight loss process. Structured conversations between partners about weight management were videotaped at baseline and 6 months. Participants provided saliva samples before and after the conversations, which were assayed for cortisol and salivary alpha-amylase (sAA) to determine physiological stress and anxiety responses to conversations about weight. The results indicated that receiving support from one's partner when discussing weight-related issues was associated with greater physiological stress, as indicated by higher cortisol and sAA levels, whereas providing support to one's partner was associated with lower cortisol levels and higher sAA levels. The findings suggest that receiving support is not a universally positive experience, especially for populations facing health issues. The mixed findings for support provision align with previous studies identifying a negative association between affectionate communication and cortisol levels, as well as a positive association between sAA and anxiety and emotional arousal. The findings and their implications for understanding the physiological correlates of couples' conversations about weight are discussed.

Novel insights in endocrine and metabolic pathways in sepsis and gaps for future research

Sepsis is defined as any life-threatening organ dysfunction caused by a dysregulated host response to infection. It remains an important cause of critical illness and has considerable short- and long-term morbidity and mortality. In the last decades, preclinical and clinical research has revealed a biphasic pattern in the (neuro-)endocrine responses to sepsis as to other forms of critical illness, contributing to development of severe metabolic alterations. Immediately after the critical illness-inducing insult, fasting- and stress-induced neuroendocrine and cellular responses evoke a catabolic state in order to provide energy substrates for vital tissues, and to concomitantly activate cellular repair pathways while energy-consuming anabolism is postponed. Large randomized controlled trials have shown that providing early full feeding in this acute phase induced harm and reversed some of the neuro-endocrine alterations, which suggested that the acute fasting- and stress-induced responses to critical illness are likely interlinked and benefical. However, it remains unclear whether, in the context of accepting virtual fasting in the acute phase of illness, metabolic alterations such as hyperglycemia are harmful or beneficial. When patients enter a prolonged phase of critical illness, a central suppression of most neuroendocrine axes follows. Prolonged fasting and central neuroendocrine suppression may no longer be beneficial. Although pilot studies have suggested benefit of fasting-mimicking diets and interventions that reactivate the central neuroendocrine suppression selectively in the prolonged phase of illness, further study is needed to investigate patient-oriented outcomes in larger randomized trials.

Moderate Weight Loss is associated with Reductions in LH Pulse Frequency and Increases in 24-hour Cortisol with no change in Perceived Stress in Young Ovulatory Women

OBJECTIVE

Determine the potential role of cortisol as an indicator of both metabolic and psychosocial stress and its relation to LH pulse dynamics during a three-month diet and exercise intervention causing moderate weight loss.

METHODS

Secondary analysis of a randomized, controlled trial that demonstrated the causal role of low energy availability in the disruption of the menstrual cycle. Twenty-one women aged (18-24 yrs), BMI (21.7± 1.9 kg·m^-2), completed a baseline menstrual cycle and three intervention menstrual cycles of a controlled diet and supervised exercise program. Twenty-four-hour LH pulse dynamics (q10 min) and diurnal patterns of cortisol (q60 min) as well as Perceived Stress Scale scores were determined in the early follicular phase prior to the intervention and in the post intervention cycle. Pre to post comparisons were determined with paired t-tests, and Pearson bivariate correlations assessed associations.

RESULTS

Subjects lost weight (-2.8±1.97 kg) and LH pulse frequency declined pre=0.79±0.23 pulses·hr^-1 to post=0.60±0.29 pulses·hr^-1 (p=0.014). Weight loss was associated with an increase in cortisol AUC R=-0.473, (p=0.03) and the decline in LH pulse frequency R= 0.523; (p=0.026). Increases in cortisol AUC were associated with declines in LH pulse frequency R=-0.472; (p=0.048). The morning cortisol rise AUC increased from pre=2140±878 µg·dL^-1 · day to post=2556±1067 µg·dL^-1 · day (p=0.034). Changes in PSS were not associated with changes in LH or cortisol.

CONCLUSION

The initial perturbation of LH pulsatility with moderate diet and exercise is associated with metabolically driven increases in cortisol AUC with no influence of psychological stress.

Very Low-Calorie Ketogenic Diet: A Potential Application in the Treatment of Hypercortisolism Comorbidities

A very low-calorie ketogenic diet (VLCKD) is characterized by low daily caloric intake (less than 800 kcal/day), low carbohydrate intake (<50 g/day) and normoproteic (1−1.5 g of protein/kg of ideal body weight) contents. It induces a significant weight loss and an improvement in lipid parameters, blood pressure, glycaemic indices and insulin sensitivity in patients with obesity and type 2 diabetes mellitus. Cushing’s syndrome (CS) is characterized by an endogenous or exogenous excess of glucocorticoids and shows many comorbidities including cardiovascular disease, obesity, type 2 diabetes mellitus and lipid disorders. The aim of this speculative review is to provide an overview on nutrition in hypercortisolism and analyse the potential use of a VLCKD for the treatment of CS comorbidities, analysing the molecular mechanisms of ketogenesis.

Examination of Sleep and Obesity in Children and Adolescents in the United States

PURPOSE

This study contributes to the growing literature on the association between sleep and obesity by examining the associations between hours of sleep, consistency of bedtime, and obesity among children in the US.

DESIGN

Analysis of a nationally representative sample of non-institutionalized children from the 2016-17 National Survey of Children's Health.

SETTING

US, national.

SUBJECTS

Children ages 10-17 years (n = 34,640).

MEASURES

Parent reported weeknight average hours of sleep and consistency of bedtime. Body mass index classified as underweight, normal, overweight or obesity using parent-reported child height and weight information, classified using CDC BMI-for-Age Growth Charts.

ANALYSIS

Multivariate logistic regression models were used to estimate associations between measures of sleep and body mass index weight category adjusting for individual, household and neighborhood characteristics.

RESULTS

An additional hour of sleep was associated with 10.8% lower odds of obesity, net of consistency in bedtime. After controlling for sleep duration, children who usually went to bed at the same time on weeknights had lower odds of obesity (24.8%) relative to children who always went to bed at the same time.

CONCLUSION

Sleep duration is predictive of lower odds of obesity in US children and adolescents. Some variability in weeknight bedtime is associated with lower odds of obesity, though there were no additional benefits to extensive variability in bedtime.

Psychosocial correlates of body esteem and disordered eating among sexual minority adolescent girls

The present study examined whether body esteem mediates the associations between psychosocial factors, including peer victimization and parent-adolescent relationship quality, and multiple categories of disordered eating (DE) within a diverse sample of adolescent sexual minority (SM) girls. Participants were 528 girls, aged 14-18 years, recruited as part of a larger online study on LGBTQ + adolescent health. Participants anonymously completed self-report measures of parent-adolescent relationship quality, sexual orientation-based victimization, body esteem, and DE behaviors, including binge eating, purging, and caloric restriction. Parent-adolescent relationship quality was positively associated with SM adolescent girls' body esteem, and some aspects of body esteem subsequently mediated the associations between parent-adolescent relationship quality and DE behaviors. Experiences of sexual orientation-related victimization were also positively related to endorsement of caloric restriction. However, no significant indirect effects were observed between sexual orientation-related victimization and DE via body esteem. These results suggest parents could influence their SM daughters' DE behaviors via body esteem, and SM girls may be engaging in caloric restriction if they experience victimization, regardless of their body esteem.

Drive for thinness in adolescents predicts greater adult BMI in the Growth and Health Study cohort over 20 years

OBJECTIVE

In youth, a preoccupation with weight and the desire to be thinner, or drive for thinness, might persist into adulthood and predict reward-based compulsive eating and greater weight status.

METHODS

A total of 623 women were enrolled from a prospective cohort study starting at 10 years old and assessed up to 20 years later. Drive for thinness was measured five times during adolescence. In adulthood (mean age = 39.5), drive for thinness, reward-based eating drive, and BMI were measured.

RESULTS

Structural equation modeling found cumulative adolescent drive for thinness predicted higher scores for both adult drive for thinness and reward-based eating drive. Youth drive for thinness was not directly associated with adult BMI but rather indirectly through adult drive for thinness. Reward-based eating drive was not associated with adult BMI.

CONCLUSIONS

Drive for thinness during the critical developmental years may exert long-term effects on adulthood eating behaviors tied to greater weight gain, potentially reflecting an important early target of intervention.

The effectiveness of acceptance and commitment therapy upon weight management and psychological well-being of adults with overweight or obesity: A systematic review

Several studies have examined acceptance and commitment therapy's (ACT) effectiveness for addressing physical and psychological distress people with obesity can face. Nevertheless, no review focusing specifically on ACT analysing randomized controlled trials (RCT) has been done up to date in this field. The present systematic review was developed following the PRISMA statement and aimed to examine ACT's effects on weight management and psychological well-being of adults with overweight or obesity. A conjunction of keywords related to ACT and excess weight was searched in four databases (Medline, PubMed, Psycinfo and Scopus) for articles meeting inclusion criteria. The literature search yielded 2,074 papers, and 16 were included in the review, finally. In 71.43% of the studies, ACT was effective to enhance psychological well-being; in 50% effectively targeted process variables and health behaviours related to weight management; in 31.82% of studies, physical variables were improved; and 21.38% of studies showed evidence in favour of ACT for eating behaviour modification. The present review supports ACT for promoting emotional aspects of individuals immersed in such weight-related battles and highlights the benefits of psychological well-being-oriented ACT in the context of obesity treatment. More studies targeting psychological well-being primarily and with longer follow-ups are required.

Corticosterone and chlorpyrifos oxon exposure elicits spatiotemporal MAPK phosphoprotein signaling in a mouse brain

Chlorpyrifos (CPF) is one of the most widely-used pesticides globally for agricultural purposes. Certain occupations (e.g., farmers, military) are at an increased risk for high-dose exposure to CPF, which can lead to seizures and irreversible brain injury. Workers with the highest risk of exposure typically experience increased circulating cortisol levels, which is related to physiological stress. To better represent this exposure scenario, a mouse model utilized exogenous administration of corticosterone (CORT; high physiologic stress mimic) in combination with chlorpyrifos oxon (CPO; oxon metabolite of CPF); this combination increases neuroinflammation post-exposure. In the present study adult male C57BL/6J mice were given CORT (200 μg/mL) in drinking water for seven days followed by a single intraperitoneal injection of CPO (8.0 mg/kg) on day eight, and euthanized 0.5, 2, and 24 h post-injection. Ten post-translationally modified proteins were measured in the frontal cortex and striatum to evaluate brain region-specific effects. The spatiotemporal response to CORT + CPO sequentially activated phosphoproteins (p-ERK1/2, p-MEK1/2, p-JNK) involved in mitogen-activated protein kinase (MAPK) signaling. Observed p-ZAP70 responses further integrated MAPK signaling and provided a spatiotemporal connection between protein phosphorylation and neuroinflammation. This study provides insight into the spatiotemporal cellular signaling cascade following CORT + CPO exposure that represent these vulnerable populations.

Impact of income and perceived stress on engagement and weight loss outcomes in an online behavioral weight loss program

Lower income is associated with greater stress, and stress has been shown to undermine treatment engagement and weight loss outcomes in face-to-face interventions. The present study examined whether lower income predicts treatment engagement and weight loss outcomes during an online behavioral weight loss (BWL) intervention. A total of N = 260 participants (79.2% female; 50.7 ± 11.9 years of age; 60.3% non-Hispanic White) were enrolled into an online BWL program and had their income, stress, program engagement, and weight measured. Results showed that stress fully mediated the effect of income on engagement in the online program. Further, lower income predicted poorer weight loss outcomes, and this effect was partially mediated by perceived stress. This is the first study to demonstrate that lower income is associated with poorer engagement and weight loss outcomes in an online weight loss program, underscoring the need for systems-level stress reduction programs and individual level stress management tools, particularly for individuals with lower income.

Non-invasive assessment of metabolic responses to food restriction using urinary triiodothyronine and cortisol measurement in macaques

Regulation of energy allocation and metabolic rate plays an important role in determining behavior and fitness in wild animals, calling for the validation of non-invasive markers of energetic condition. Recently, the thyroid hormone triiodothyronine (T3) has emerged as a promising marker as concentrations decrease to lower the metabolic rate during energetically challenging periods. However, it remains largely unclear whether T3 merely represents an alternative or provides additional information compared to other compounds involved in the regulation of energy acquisition and allocation, like cortisol and C-peptide, as few joint measurements have been conducted to date in non-invasively collected samples. We aimed to validate the non-invasive measurement of immunoreactive urinary total T3 (uTT3), in comparison to urinary cortisol (uCort) and urinary C-peptide (uCP), as a marker of metabolic response to variation in food intake in macaques, and to address a number of issues regarding the collection, storage and processing of samples which are important for application of uTT3 measurements under field conditions. We used daily samples and body mass measures from a prior food restriction-refeeding experiment over 4 weeks with six captive macaques and analyzed concentrations of uTT3 and uCort in samples collected prior to (fasting) and after morning feeding (non-fasting). Concentrations of uTT3 decreased in response to restriction in food supply and were also lower during weeks of food restriction compared to weeks of refeeding. Variation in uTT3 also correlated positively with variation in body mass and concentrations of uCP. As expected, uCort showed the reverse pattern, increasing during food restriction and decreasing following refeeding, but was not associated with variation in body mass. Generally, compared to fasting samples, concentrations were higher in post-morning feeding, i.e. non-fasting, samples for uTT3 but not uCort. Contamination of urine samples with fecal matter, but not soil, and exposure to UV light led to a decrease in uTT3. uTT3 was largely unaffected by repeated freeze-thaw cycles and by refrigeration for medium-term storage (2 days) but degraded substantially when stored at ambient temperature for the same period. In conclusion, uTT3 measurements inform on the effect of food intake and its associated metabolic response to variation in energetic status. Since uTT3 is reasonably robust to many issues associated with collection and storage of urine samples under field conditions, it is a promising biomarker for studies of energetic condition and basal metabolic rate in wild macaques.

Effect of Calorie Restriction and Exercise on Type 2 Diabetes

Type-2 diabetes (T2D) is a chronic condition, generally regarded as an irreversible, that is among the top 10 causes of death globally. The hallmark of T2D is hyperglycemia, which results from disturbances in insulin sensitivity, insulin secretion, β-cell dysfunction and insulin resistance. Several clinical and lifestyle factors are involved in the progression of T2D, such as obesity and physical inactivity. A high-calorie diet is the main contributor to the development of obesity, which results in T2D, as obesity or increased intra-abdominal adipose tissue is related to insulin resistance. Technological advances have contributed to individuals having a more sedentary lifestyle, leading to obesity and T2D. T2D can be treated with lifestyle interventions, such as diet and exercise. Herein, we highlight the positive impact of a very low-calorie diet (VLCD) and lifestyle modalities in the treatment and prevention of T2D. An inclusion of VLCD 400-800 kcal/day for 8 weeks and ≥ 150 minutes exercise 5 times a week as lifestyle interventions can decrease glucose levels to normal, reduce HbA1c and improve insulin resistance and sensitivity. Therefore, a potential mechanism in maintaining glucose homeostasis and remission of T2D by VLCD and exercise reduces body weight.

The effect of antecedent exercise on the acute stress response and subsequent food consumption: a preliminary investigation

Physical activity has been shown to be protective against many of the deleterious consequences of stress; however, the effects of exercise on stress-induced food consumption are unclear. This study examined the effect of an acute bout of exercise prior to exposure to an acute stressor on subsequent eating behavior, together with the physiological (e.g., heart rate, blood pressure, salivary cortisol) and psychological (e.g., mood, perceived stress) responses to stress. Twenty-three men and women completed four experimental conditions (control, exercise only, stress only, and exercise prior to stress) conducted in a counterbalanced order using a within-subjects repeated measures design. Ad libitum energy intake from a laboratory test meal was assessed at each trial, together with monitoring of physiological and psychological responses. No difference in total energy intake (p = 0.146) or energy intake from 'unhealthy' foods was noted between conditions (p = 0.783), despite lower circulating ghrelin when antecedent exercise was performed compared with stress alone (p < 0.05). Exposure to an acute stressor is not necessarily associated with alterations in subsequent food intake, nor does antecedent exercise prior to stress exposure affect food choices, despite transient alterations in the hunger hormone ghrelin.

Effects of Health Behavior Interventions on Psychosocial Outcomes and Cortisol Regulation Among Chronically Stressed Midlife and Older Adults

BACKGROUND

Altered cortisol dynamics have been associated with increased risk for chronic health problems among midlife and older adults (≥ 45 years of age). Yet, studies investigating the impact of health behavior interventions on cortisol activity in this age group are limited.

OBJECTIVE AND METHODS

The current study examined whether 48 midlife and older adults (50% family caregivers, 69% women) randomized to one of four telephone-based health behavior interventions (stress management (SM), exercise (EX), nutrition (NUT), or exercise plus nutrition (EX+NUT)) showed improvements in their perceived stress, mood, and cortisol dynamics at 4 months post-intervention. Participants collected four salivary cortisol samples (waking, 30 min after waking, 4 p.m., and bedtime) across two collection days at baseline and at 4 months post-intervention to assess for total cortisol, cortisol awakening response (CAR), and diurnal cortisol slope.

RESULTS

Participants in SM showed lower levels of total cortisol and a smaller CAR compared with those in EX, NUT, or EX+NUT from baseline to 4 months post-intervention. Participants in EX showed lower levels of perceived stress, depression, and anxiety compared with those in NUT or SM. Finally, participants in NUT showed a greater diurnal decline in cortisol and lower levels of anxiety compared with those in SM.

CONCLUSIONS

These findings provide support for the efficacy of telephone-based, health behavior interventions in improving different stress outcomes among chronically stressed midlife and older adults and suggest the need to test the longer-term effects of these interventions for improving health outcomes in this population.

Intuitive eating as a counter-cultural process towards self-actualisation: An interpretative phenomenological analysis of experiences of learning to eat intuitively

This research presents an in-depth idiographic study that illustrates how learning to eat intuitively involves socio-cultural challenges, strategies of resistance and self-actualising processes. Interviews were conducted with eight women who had been practising intuitive eating (IE) for at least 1.5 years. Data was analysed using IPA and four themes were drawn inductively from the data: IE as an ongoing process, perceived judgement of others, strategies of resistance and processes of self-actualisation. Further research is needed to explore experiences of learning to eat intuitively amongst different samples and with different cultures, and to further investigate the relationship between IE and the actualising tendency.

Western diet, obesity and bariatric surgery sequentially modulated anxiety, eating patterns and brain responses to sucrose in adult Yucatan minipigs

Palatable sweet/fatty foods overconsumption is a major risk factor for obesity and eating disorders, also having an impact on neuro-behavioural hedonic and cognitive components comparable to what is described for substance abuse. We hypothesized that Yucatan minipigs would show hedonic, cognitive, and affective neuro-behavioral shifts when subjected to western diet (WD) exposure without weight gain, after the onset of obesity, and finally after weight loss induced by caloric restriction with (RYGB) or without (Sham) gastric bypass. Eating behavior, cognitive and affective abilities were assessed with a spatial discrimination task (holeboard test) and two-choice feed tests. Brain responses to oral sucrose were mapped using 18F-FDG positron emission tomography. WD exposure impaired working memory and led to an “addiction-type” neuronal pattern involving hippocampal and cortical brain areas. Obesity induced anxiety-like behavior, loss of motivation, and snacking-type eating behavior. Weight loss interventions normalized the motivational and affective states but not eating behavior patterns. Brain glucose metabolism increased in gustatory (insula) and executive control (aPFC) areas after weight loss, but RYGB showed higher responses in inhibition-related areas (dorsal striatum). These results showed that diet quality, weight loss, and the type of weight loss intervention differently impacted brain responses to sucrose in the Yucatan minipig model.

Food Addiction and Psychosocial Adversity: Biological Embedding, Contextual Factors, and Public Health Implications

The role of stress, trauma, and adversity particularly early in life has been identified as a contributing factor in both drug and food addictions. While links between traumatic stress and substance use disorders are well documented, the pathways to food addiction and obesity are less established. This review focuses on psychosocial and neurobiological factors that may increase risk for addiction-like behaviors and ultimately increase BMI over the lifespan. Early childhood and adolescent adversity can induce long-lasting alterations in the glucocorticoid and dopamine systems that lead to increased addiction vulnerability later in life. Allostatic load, the hypothalamic-pituitary-adrenal axis, and emerging data on epigenetics in the context of biological embedding are highlighted. A conceptual model for food addiction is proposed, which integrates data on the biological embedding of adversity as well as upstream psychological, social, and environmental factors. Dietary restraint as a feature of disordered eating is discussed as an important contextual factor related to food addiction. Discussion of various public health and policy considerations are based on the concept that improved knowledge of biopsychosocial mechanisms contributing to food addiction may decrease stigma associated with obesity and disordered eating behavior.