The construct validity of the Restraint Scale among mainland Chinese women

Structural and functional neural patterns among sub-threshold bulimia nervosa: Abnormalities in dorsolateral prefrontal cortex and orbitofrontal cortex

BACKGROUND

Disordered eating behaviors are prevalent among youngsters and highly associated with dysfunction in neurocognitive systems. We aimed to identify the potential changes in individuals with bulimia symptoms (sub-BN) to generate insights to understand developmental pathophysiology of bulimia nervosa.

METHODS

We investigated group differences in terms of degree centrality (DC) and gray matter volume (GMV) among 145 undergraduates with bulimia symptoms and 140 matched control undergraduates, with the secondary analysis of the whole brain connectivity in these regions of interest showing differences in static functional connectivity (FC).

RESULTS

The sub-BN group exhibited abnormalities of the right dorsolateral prefrontal cortex and right orbitofrontal cortex in both GMV and DC, and displayed decreased FC between these regions and the precuneus. We also observed that sub-BN presented with reduced FC between the calcarine and superior temporal gyrus, middle temporal gyrus and inferior parietal gyrus. Additionally, brain-behavioral associations suggest a distinct relationship between these FCs and psychopathological symptoms in sub-BN group.

CONCLUSIONS

Our study demonstrated that individuals with bulimia symptoms present with aberrant neural patterns that mainly involved in cognitive control and reward processing, as well as attentional and self-referential processing, which could provide important insights into the pathology of BN.

Peer Teasing and Restrained Eating among Chinese College Students: The Chain Mediating Role of Negative Coping Styles and Negative Physical Self

This study aimed to determine whether negative coping styles and negative physical self sequentially mediate the relationship between peer teasing and restrained eating among Chinese university students. In total, 1127 participants (66.9% women, average age = 18.43 years; age range, 14-26 years) completed the Perception of Teasing Scale, Coping Style Questionnaire, Negative Physical Self Scale, and the Chinese version of the Restraint Scale. The mediational analysis showed that, after controlling for age, sex, and body mass index (BMI), peer teasing was related to restrained eating behaviors through (a) the mediating effect of negative coping styles, (b) the mediating effect of negative physical self, and (c) the chain-mediating effect of negative coping styles and negative physical self. This study showed for the first time that negative coping styles and negative physical self may chain mediate the association between peer teasing and restrained eating. It also provides suggestions for clinical practices as to strategies for controlling restrained eating.

The Association of Restrained Eating and Overeating during COVID-19: A Cross-Lagged Model

Widespread overeating has been found during the 2019 coronavirus (COVID-19) pandemic. The present study investigated whether pre-pandemic restrained eating (RE) predicted overeating during the pandemic, and further explored the behavioral (mortality threat, negative affect) mechanisms underlying this association. An eight-month longitudinal survey was conducted with a large sample of 616 undergraduates from Southwest university. From September 2019 to April 2020, three measurements were conducted. RE was tested before the pandemic (T1), and data of mortality threat, negative affect, and overeating were collected at the middle (T2) and end of (T3) the COVID-19 crisis in China. The correlation results showed that baseline RE was positively associated with mortality threat, negative affect, and overeating at T2 and T3. Moreover, negative affect and mortality threat were positively correlated with overeating. Results from longitudinal mediation showed that baseline RE would positively predict T3 overeating through T2 negative affect, but not T2 mortality threat. This study supports and extends the counterregulatory eating hypothesis that RE positively predicts future overeating, especially through negative emotions. These findings further reveal the core psychological mechanism underlying this positive RE-overeating relation in the context of COVID-19, indicating that the individuals with higher RE could not cope with negative affect adequately, contributing to more overeating.

Influence of negative mood on restrained eaters' memory suppression of food cues: An event-related potentials study

Negative mood has been found to be a critical trigger for overeating in restrained eaters. The ability to suppress thinking of palatable food cues is crucial to control hedonic eating; nevertheless, little research has been conducted to explore inhibitory control in cognitive processes among restrained eaters. To address this gap, this study primed restrained eaters with negative (n = 23) or neutral emotions (n = 24) and applied a Think/No-think paradigm to explore their retrieval facilitation/suppression ability for food cues, while recording Electroencephalogram (EEG) data. Results indicated that the recall rate of the No-think condition (retrieval suppressing task) was higher than the Think condition (retrieval task). Negative affect did not influence the recall rate, but it did evoke smaller N2 amplitudes, larger P2 and P3 amplitudes, as well as late positive component (LPC) amplitudes. Among these components, P2 evoked by the No-think and Think conditions was larger than the perceptual control condition. Our findings suggested that in negative moods, restrained eaters need to allocate more attentional resources to suppress food cues. The findings further demonstrated that the influence of negative moods appeared at an early stage of cognitive processing and caused a resource depletion in memory suppression. This research provides a neurophysiological basis for understanding emotional influences on the process of restrained eaters' inhibition control for external food cues.

Acupuncture or metformin to improve insulin resistance in women with polycystic ovary syndrome: study protocol of a combined multinational cross sectional case-control study and a randomised controlled trial

INTRODUCTION

Polycystic ovary syndrome (PCOS) is linked to hyperinsulinemia and insulin resistance with dysfunctional glucose metabolism. Pilot studies suggests that acupuncture treatment with combined manual and low-frequency electrical stimulation (electroacupuncture (EA)) of the needles decrease circulating glycated haemoglobulin (HbA1c) and homeostatic model assessment-insulin resistance. Therefore, we here aim to investigate if acupuncture treatment or metformin together with lifestyle or lifestyle management alone improves insulin sensitivity and related symptoms in overweight/obese women with PCOS.

METHODS AND ANALYSIS

This is a two-centre multinational (Sweden and China), cross-sectional case-control study combined with an open-labelled randomised controlled trial (RCT). Participants are randomised to one of three groups: (1) EA 2-3 times/week during 4 months+lifestyle management; (2) metformin, 500 mg, three/day during 4 months+lifestyle management; or (3) lifestyle management alone. The primary outcome measure in the RCT is changes in HbA1C. A total of 123 obese overweight women with PCOS will be enrolled and randomised into one of the three groups with a target power of at least 80% and 5% significance level based on two-sided tests.

ETHICS AND DISSEMINATION

The study has been approved by the Regional Ethical Review Board of Stockholm and of Peking University Third Hospital, China. Primary outcome data of the RCT will be published in a relevant journal together with supporting secondary outcome measurements. Further, outcome measurements will be published in separate papers as well as case-control data.

EXPECTED RESULTS

We anticipate that EA and metformin, both with lifestyle management, are equally effective and superior to lifestyle management alone for improvement of glycaemic control.

TRIAL REGISTRATION NUMBERS

NCT02647827 and EudraCT2015-004250-18.

Regional Gray Matter Volume Is Associated with Restrained Eating in Healthy Chinese Young Adults: Evidence from Voxel-Based Morphometry

Highlight

Participants were non-clinical young adults with different restrained eating levels.

We assessed relations of restrained eating (RE) with regional gray matter volume (rGMV).

High RE scores were related to larger GMV in specific areas related to reward.

High RE scores were also linked to less GMV in regions related to response inhibition.

Objective: Dieting is a popular method of weight control. However, few dieters are able to maintain initial weight losses over an extended period of time. Why do most restrained dieters fail to lose weight? Alterations in brain structures associated with restrained eating (RE) represent one potentially important mechanism that contributes to difficulties in maintaining weight loss within this group. To evaluate this contention, we investigated associations between intentional, sustained restriction of food intake to lose or maintain body weight, and regional gray matter volume (rGMV) within a large non-clinical young adult, sample.

Methods: Participants (150 women, 108 men) completed measures of RE and demographics prior to undergoing an MRI scan. Voxel-based morphometry (VBM) evaluated strengths of association between RE scores and rGMV.

Results: Higher RE levels corresponded to more rGMV in regions linked to risk of overeating and binge-eating including the left insula and orbitofrontal cortex (OFC). Conversely, RE had significant negative correlations with rGMV in the left and right posterior cingulum gyrus, regions linked to inhibitory control and potential risk for future weight gain.

Conclusions: Together, findings suggested individual differences in RE among young adults correspond to GMV variability in regions linked to overweight and obesity risk.

Altered frontal inter-hemispheric resting state functional connectivity is associated with bulimic symptoms among restrained eaters

Theory and research have indicated that restrained eating (RE) increases risk for binge-eating and eating disorder symptoms. According to the goal conflict model, such risk may result from disrupted hedonic-feeding control and its interaction with reward-driven eating. However, RE-related alterations in functional interactions among associated underlying brain regions, especially between the cerebral hemispheres, have rarely been examined directly. Therefore, we investigated inter-hemispheric resting-state functional connectivity (RSFC) among female restrained eaters (REs) (n=23) and unrestrained eaters (UREs) (n=24) following food deprivation as well as its relation to overall bulimia nervosa (BN) symptoms using voxel-mirrored homotopic connectivity (VMHC). Seed-based RSFC associated with areas exhibiting significant VMHC differences was also assessed. Compared to UREs, REs showed reduced VMHC in the dorsal-lateral prefrontal cortex (DLPFC), an area involved in inhibiting hedonic overeating. REs also displayed decreased RSFC between the right DLPFC and regions associated with reward estimation--the ventromedial prefrontal cortex (VMPFC) and posterior cingulate cortex (PCC). Finally, bulimic tendencies had a negative correlation with VMHC in the DLPFC and a positive correlation with functional connectivity (DLPFC and VMPFC) among REs but not UREs. Findings suggested that reduced inter-hemispheric functional connectivity in appetite inhibition regions and altered functional connectivity in reward related regions may help to explain why some REs fail to control hedonically-motivated feeding and experience higher associated levels of BN symptomatology.