Changes in the prevalence and sociodemographic correlates of eating disorder symptoms from 2013 to 2020 among a large national sample of U.S. young adults: A repeated cross-sectional study

Bidirectional relationships between nicotine vaping and maladaptive eating behaviors among young adults

Background

Past research indicates that young adult cigarette smokers are at risk of engaging in maladaptive eating behaviors (MEBs); however, whether this relationship extends to nicotine vaping is unclear. The current study assessed bidirectional associations between four types of MEBs and nicotine vaping among young adults.

Methods

1,303 young adults (20.5 ± 2.3 years; 63 % female) from a public, urban university were recruited and completed online surveys at six-month intervals from spring 2021 (W1) to spring 2023 (W5). Past 30-day nicotine vaping and four types of MEBs (susceptibility to external cues, emotional eating, routine restraint, and compensatory restraint) were evaluated.

Results

Longitudinal cross-lagged models examined the bidirectional relationships between past 30-day nicotine vaping and each type of MEB across five waves. Nicotine vaping predicted both susceptibility to external cues (β = 0.10, p <.05; Wave 2 to 3) and emotional eating (β = 0.08, p <.05; Wave 1 to 2). A significant cross-lag regression (Wave 4 to 5) showed nicotine vaping predicted to routine restraint (β = 0.08, p <.05), and routine restraint predicted to nicotine vaping (β = 0.12, p <.05).

Conclusions

Results indicated that nicotine vaping predicted MEBs; however, the type of MEB differed across waves, which may have been due to the COVID-19 pandemic context. Nicotine vaping predicted to MEBs reflecting vulnerability to the external environment and emotion regulation during a period of heightened restrictions, whereas later when pandemic restrictions had ceased nicotine vaping predicted only to routine restraint. Integrating research and practice on nicotine vaping and MEBs may inform public health efforts to decrease co-occurring health-risks in young adulthood.

Daily Relationship Functioning and Disordered Eating Behaviors Among Sexual Minority Women in Same-Sex Relationships

BACKGROUND AND PURPOSE

The present study aimed to examine associations between different types of relationship functioning and disordered eating behaviors (DEBs) in the everyday lives of sexual minority women in same-sex relationships-an at-risk population that has not been assessed in this context.

METHODS

Participants included 321 young sexual minority women (Mage = 27.56, SD = 3.67) in same-sex relationships who completed surveys assessing their daily relationship functioning and DEB use each day for a 14-day daily diary period. Multilevel structural equation modeling was used to examine daily-, person-, and couple-level associations among women's daily relationship functioning (general relationship functioning, positive and negative relational behaviors they and, separately, their partners engaged in) and DEBs (overeating, loss of control eating, emotional eating, and dietary restriction).

RESULTS

Results generally indicated that more positive and less negative daily relationship functioning across all assessed constructs was associated with less same-day emotional eating. In contrast, associations between all daily relationship functioning constructs and loss of control eating were not significant, nor were any relationship functioning-DEB associations at the couple level. More circumscribed patterns of association were identified for associations between the relationship functioning constructs, and overeating and dietary restriction.

CONCLUSIONS

Collectively, these findings provide insight into how aspects of daily relationship functioning map onto sexual minority women's daily engagement in DEBs that are linked to poor health long-term, and directions for future research and clinical practice that may warrant consideration moving forward to help advance the evidence-base and care for this historically overlooked and underserved population.

Cross-sectional and longitudinal associations between higher weight and eating disorder risk among collegiate athletes

OBJECTIVES

To examine whether higher weight status is associated with increased eating disorder risk in athletes.

DESIGN

Study 1 used cross-sectional (N = 942) and longitudinal (N = 483) data collected over a five-year period from Division I athletes at a Midwestern university. Study 2 used cross-sectional data from athletes competing at various levels at universities across the United States (N = 825).

METHODS

Weight and height were measured in Study 1 and self-reported in Study 2; higher weight was defined as body mass index ≥ 25 kg/m2. Eating disorder risk was assessed with preliminary (Study 1) and final (Study 2) versions of the Eating Disorders Screen for Athletes. Study 1 examined weight status in relation to both concurrent and one-year changes in Eating Disorder Screen for Athletes score. Study 2 examined weight status in relation to both the Eating Disorders Screen for Athletes score and elevated eating disorder risk using the established Eating Disorders Screen for Athletes cut-off. All models adjusted for gender and sport type; Study 2 additionally adjusted for race/ethnicity, age, and competition level.

RESULTS

Across studies, higher weight status was significantly associated with increased eating disorder risk among athletes. This association was observed both cross-sectionally and longitudinally, and the prevelence of elevated eating disorder risk was 43 % greater among athletes with higher weight status than among those without higher weight status.

CONCLUSIONS

Despite existing stereotypes that eating disorders tend to occur with low weight status, findings highlight the importance of screening all athletes for eating disorders, regardless of their weight status.

A preliminary investigation of the causal role of social media use in eating disorder symptoms

BACKGROUND AND OBJECTIVES

Research has consistently shown that greater social media use is associated with elevated eating disorder (ED) symptoms. Importantly, however, the investigation of this relationship has largely relied upon the use of self-report measures of social media use in the context of correlational designs. Given that correlational studies do not permit inferences regarding causation, and recent findings questioning the validity of self-report social media use, it is critical to corroborate past findings using experimental designs and objective measures. The current study sought to experimentally determine the potential causal impact of social media use in ED symptoms.

METHODS

Participants completed an initial testing session to assess objective smartphone social media use and ED symptoms, following which they were randomly assigned to either suspend social media use for one week or use social media as usual. One week later, participants completed a second testing session to again assess social media use and ED symptoms.

RESULTS

Results revealed that the manipulation exerted an impact on ED symptoms, such that participants who successfully reduced social media use exhibited a significant reduction in ED symptoms, and these symptoms were significantly attenuated as compared to participants in the control condition.

LIMITATIONS

The current study did not employ an active control condition and almost a quarter of participants were excluded due to dropout or non-compliance.

CONCLUSION

Findings are consistent with the causal impact of social media use in ED symptoms and suggest that a brief social media 'holiday' may reduce ED symptoms in undergraduate students.

Associations between affect dynamics and eating regulation in daily life: a preliminary ecological momentary assessment study

Disordered eating behaviors consistently associated with emotion regulation difficulties. However, most studies have focused on affect intensity without considering dynamic affective patterns. We examined these patterns in relation to daily overeating, loss of control eating (LOCE), dietary restraint, and food craving in young adults using ecological momentary assessment (EMA).Adults (N = 24) completed a 10-day EMA protocol during which they reported momentary affect and eating patterns. Generalized linear mixed-models examined each index in relation to eating variable.Higher PA instability (within-person) was associated with higher ratings of binge-eating symptoms (B = 0.15, SE = 0.06, p = 0.007). Lower NA differentiation (within-person) was associated with higher levels of food craving (B = -10.11, SE = 4.74, p = 0.033).Our results support previous findings suggesting that acute fluctuations in PA may increase risk of binge-eating symptoms. Further, inability to differentiate between momentary states of NA was associated with cravings. This study highlights the importance of examining multiple facets of NA and PA in relation to eating regulation.Trial registration: ClinicalTrials.gov identifier: NCT02945475.

An Umbrella Review and a Meta-analysis of Meta-analyses of Disordered Eating Among Medical Students

Objective

To prevent eating disorders in future physicians, this umbrella review and meta-analysis of previous meta-analyses estimates the prevalence of disordered eating (DE) among medical students worldwide and identifies key risk factors.

Methods

Four databases were searched electronically between their inception and February 1, 2023. The search was later updated to December 31, 2023.

Results

The search yielded prevalence rates for medical students who scored above established cutoffs on validated assessment measures for DE. These were computed to provide an overall pooled estimate. The data was taken from 2 previous reviews. Both these systematic reviews found a 15.1% (95% confidence interval [CI]: 14.7%-15.6%) prevalence rate of DE among medical students. The equivalent Hedges' G = 0.30 (95% CI: 0.29-0.31), the equivalent odds ratio = 1.74 (95% CI: 1.71-1.77), I2 = 97.6%, and the excess of statistical significance is P = .001. The trim and fill adjusted effect size was 16.0% (95% CI: 14.0%-20.0%).

Conclusion

Because eating disorders put students' safety and well-being at risk and because the health of early-stage physicians is vital to the welfare of a country, early signs of disordered eating must become a priority of medical schools and a signal for effective prevention and intervention. The recommendation is to ensure supportive environments, provide easy access to effective care, and hold clear expectations for student eating behavior.

Factors increasing the risk for food addiction in Ecuadorian students

Background

Food addiction (FA) is a construct that has gained interest in recent years, but its relevance in the Ecuadorian population has not yet been explored. The aims of this study were to explore the differences in the psychological profile (including FA) between university students from Ecuador and to identify the underlying structure of the relationships of the FA severity level through a mediational model.

Methods

The sample consisted of 972 university students, women and men (mean age: 20.1 years old, SD = 2.6), recruited from four Ecuadorian regions. The assessment tools included a unidimensional scale of FA, eating-related measures, emotion regulation state, impulsivity, and psychopathology state. Path analysis modeled the direct and indirect effects explaining the FA severity level.

Results

The results indicated that higher psychopathological levels were associated with FA. Similarly, no differences in FA were observed between the Ecuadorian regions. The path analysis suggested that older age, female sex, and higher difficulties in emotional regulation, impulsivity, negative mood, and anxiety trigger disordered eating; subsequently, more impaired eating behavior impacted the FA level.

Conclusion

FA is a complex clinical entity that includes multiple components related to eating disorders (EDs) and other mental health problems. The results of this study provide empirical knowledge for designing evidence-based prevention and treatment strategies.

Intersectionality of demographic characteristics in self-reported anorexia nervosa, bulimia nervosa, and probable eating disorders among college students

OBJECTIVE

To investigate associations between identity intersectionality, with a primary focus on minority identity, and probable eating disorders (EDs) within the US college student population.

METHOD

Data consisting of n = 414,299 college students' responses to the American College Health Association's National College Health Assessment between fall 2015 and spring 2019 were utilized for this study. Overall and stratified adjusted odds ratios (aORs) were used to assess the association between different facets of identity (i.e., race/ethnicity, gender identity, and sexual orientation) and probable EDs.

RESULTS

Among all, in our analytic sample, 7.15% reported a probable ED. Interactions between all three identity variables were significant, and thus stratified odds ratios were evaluated. Transgender men were significantly more likely to report probable ED than cisgender male peers within the following racial/ethnic groups: non-Hispanic White (aOR: 3.33; 95% CI: 2.79, 3.96; p < .0001), non-Hispanic Black (aOR: 3.29; 95% CI: 1.72, 6.28; p = .0003), Hispanic (aOR: 2.31; 95% CI: 1.55, 3.43; p < .0001), Asian or Pacific Islander (aOR: 2.19; 95% CI: 1.45, 3.30; p = .0002), Biracial or Multicultural (aOR: 3.36; 95% CI: 2.17, 5.22; p < .0001), and other (aOR: 4.19; 95% CI: 2.25, 7.79; p < .0001).

CONCLUSIONS

This study underscores the importance of increasing our understanding of interactions between marginalized identities and the ways in which minority identity informs ED risk.

PUBLIC SIGNIFICANCE

The impact of multiple marginalized identities on ED outcomes is not well understood. Our study expands on previous ACHA-NCHA studies by addressing identity intersectionality, looking at more than one identity at a time (i.e., specifically race/ethnicity, gender identity, and sexual orientation). Our results contribute unique risk profiles for students who identify with multiple marginalized groups. Further, they indicate that that these associations vary based on the compounded effect of the demographic factors considered.

Psychometric properties of self-report measures of eating disorder cognitions: a systematic review

BACKGROUND

Although eating disorder (ED) models display some differences in theory and treatment approach, cognitive-behavioural, schema-focused, and disorder-specific models all highlight the fundamental nature of cognitions as key factors in ED development and maintenance processes. As such, it is vital that ED cognitions continue to be assessed and monitored as therapeutic targets and treatment outcomes as well as being examined as constructs in empirical research. This review aimed to systematically identify and evaluate the psychometric properties of existing self-report measures of ED cognitions.

METHODS

A systematic review protocol was registered using the international prospective register of systematic reviews (PROSPERO; CRD42023440840). Included studies described the development, validation and/or the psychometric evaluation of a measure (or subscale) that was specifically developed to solely assess ED cognitions (that is thoughts, expectations, assumptions, or beliefs), in English-speaking, adult populations. The search was conducted using three electronic databases: PsycINFO, MedLine, and Embase. Two independent reviewers conducted screening, selection and evaluation of the psychometric properties of relevant measures using a standardised, well-established quality appraisal tool.

RESULTS

Of the initial search of 7581 potential studies, 59 met inclusion criteria and described the psychometric evaluation of 31 measures (or subscales) of ED cognitions. The findings from the current review indicate that of the included measures, none currently meet all nine criteria of adequate psychometric properties. The Eating Beliefs Questionnaire (EBQ; and EBQ-18), and the Eating Disorder Inventory Body Dissatisfaction subscale (EDI [BD]) currently possess the most evidence supporting their validity, reliability, and clinical utility.

CONCLUSIONS

The findings of the current systematic review provide guidance for future researchers to focus efforts on improving evidence for the validity, reliability and utility of self-report measures of ED cognitions. Overall, the present study has provided a detailed and systematic evaluation to support researchers and clinicians in future selection of measures of ED cognitions dependent on the specific aims of their research and treatment.

Health Consequences of Familial Negative Weight Talk Across the Spectrum of Gender Diversity

PURPOSE OF REVIEW

To synthesize differences in familial negative weight talk and health-related correlates across gender identities and to highlight gaps relevant to the unique experiences and health correlates of boys and transgender and gender diverse youth.

RECENT FINDINGS

Most of the studies included in this review observed no difference by gender in familial negative weight talk health correlates. Gender biases in existing measures, however, may have contributed to underreporting of health correlates in boys. Moreover, transgender and gender diverse youth are severely underrepresented in this research. Future research should consistently examine effect modification across gender identities and include measures that are specific to the weight-based concerns and experiences of boys and transgender and gender diverse youth.

The Impact of the First and Second Wave of the COVID-19 Pandemic on Eating Symptoms and Dysfunctional Eating Behaviours in the General Population: A Systematic Review and Meta-Analysis

BACKGROUND

The aim of this systematic review and meta-analysis was to examine the prevalence of feeding and eating disorder (FED) symptoms or dysfunctional eating behaviours (DEB) in the general population during the COVID-19 outbreak.

METHOD

We searched eligible articles in biomedical databases from 1 January 2020 to 31 March 2022. Prevalence rates of FED or DEB changes between pre-pandemic and pandemic time and correlation with psychological distress were pooled with a meta-analysis using a random-effects model. Heterogeneity was tested using I-squared (I2) statistics. A total of 186 studies with 406,076 participants met the inclusion criteria.

RESULTS

The more prevalent FED or DEB during the COVID-19 outbreak were: body image concerns (52%, 95% CI 0.38, 0.66), binge eating (40%, 95% CI 0.25, 0.55), and overeating (40%, 95% CI = 0.32-0.48). Pooled data of longitudinal studies (k = 8) only showed a significant difference in the prevalence of weight gain from pre-pandemic to the pandemic time. Finally, increased levels of psychological distress (k = 35) positively correlated with some ED symptoms.

CONCLUSION

This meta-analysis evidenced a negative impact of the pandemic on eating symptoms and DEB in the general population.

Loss-of-Control-Eating Mediates the Relationship between Cannabis-Related Problems and Eating Pathology

The prevalence of eating pathology among college students has increased significantly in recent years. This coincides with increases in the use of cannabis, both nationally, but also among college students. Problematic cannabis use has been linked to eating pathology in prior research. Research also shows that cannabis may affect appetitive drives linked to food consumption. The current study tested the hypothesis that the association between problem cannabis use and eating pathology was mediated by greater loss of control eating. Cross-sectional data were collected from a sample of 805 college student cannabis users at a large Southeastern university in the U.S. The sample were primarily Caucasian (76%) and female (65.22%) with an average age of 20.15 (SD = 3.91). Participants completed surveys assessing eating outcomes (loss of control eating and eating pathology), cannabis use, and cannabis-related problems. The analysis used an observed variable path model. After controlling for cannabis use, cannabis-related problems were indirectly linked to eating pathology via loss of control eating (B = 0.109, SE = 0.025, p < .001), supporting the primary hypothesis. The direct relationship between cannabis-related problems and eating pathology was fully accounted for (B = 0.010, SE = 0.028, p = .724) by the indirect effect of loss of control eating. These data suggest that the association between problematic forms of cannabis use and eating pathology may be due to the association between cannabis problems and loss of control eating. While this may be due to changes in appetite and food evaluation as a function of more problematic use patterns, it may also be that individuals with problematic cannabis use have more problematic eating patterns due to deficits in adaptive coping strategies. Future research should seek to parse out these different potential explanations.

Eating disorder risk in rural US adolescents: What do we know and where do we go?

Adolescence is a vulnerable period for the development of eating disorders, but there are disparities in eating disorder risk among adolescents. One population that may be at increased risk but is vastly understudied, is adolescents residing in rural regions within the United States. Rural communities face many mental and physical health disparities; however, the literature on rural adolescent eating disorder risk is nearly nonexistent. In this paper we summarize the scant literature on disordered eating and eating disorder risk and prevalence among rural US adolescents. We also detail eating disorder risk factors that may have unique influence in this population, including socioeconomic status, food insecurity, healthcare access, body image, and weight stigma. Given the presence of numerous eating disorder risk factors, we speculate that rural adolescents may be a particularly vulnerable population for eating disorders and we propose critical next steps in research for understanding eating disorder risk among the understudied population of rural adolescents. PUBLIC SIGNIFICANCE: Rural adolescents may be at increased risk for eating disorders due to disproportionate burden of known risk factors, though this relationship remains understudied. We present a summary of the literature on prevalence and unique risk factors, proposing that this may be a high-risk population. We detail next steps for research to understand eating disorder risk in this population to inform future prevention, identification, and treatment efforts needed in this community.

Disparities in eating disorder symptoms and mental healthcare engagement prior to and following the onset of the COVID-19 pandemic: Findings from a national study of US college students

OBJECTIVE

Early COVID-19 eating disorders (EDs) research used regionally restricted samples with little sociodemographic diversity. The present study aimed to address these research gaps by examining whether pandemic-related changes in ED symptoms and mental healthcare prevalence differed for historically marginalized groups within a national sample of US college students.

METHOD

Participants included 242,906 US college students (M_age  = 23.45, SD = 7.04; M_BMI  = 25.28, SD = 5.91) who completed the repeated cross-sectional multi-institute Healthy Minds Study between January 2019 and May 2021. Moderated logistic regressions examined whether pandemic-related changes in individuals' likelihoods of exhibiting current probable ED, reporting lifetime ED diagnoses, and-among individuals with current probable ED-mental healthcare engagement differed for diverse gender, sexual, and racial/ethnic identity groups, and by body mass index (BMI) and financial stress.

RESULTS

There were increases of 5% and 12% in individuals' likelihoods of exhibiting current probable ED and symptomatic individuals' mental healthcare engagement, respectively, pre- to post-COVID-19 onset, but no pandemic-related changes in lifetime ED diagnosis prevalence. There were also important variations in these time-trends for different marginalized groups. For example, individuals identifying as genderqueer/gender nonconforming and lesbian exhibited increasing ED symptoms pre- to post-COVID-19 onset, and individuals with current probable ED and higher BMIs were increasingly likely to receive mental healthcare. Associations between financial stress, and the ED and mental healthcare outcomes did not change over time.

DISCUSSION

These findings provide insight into groups of US college students that experienced disproportionate ED burden during the pandemic at the population level, and directions for research and interventions that warrant consideration.

Accessibility of Psychological Treatments for Bulimia Nervosa: A Review of Efficacy and Engagement in Online Self-Help Treatments

Bulimia nervosa is an eating disorder characterised by marked impairment to one's physical health and social functioning, as well as high rates of chronicity and comorbidity. This literature review aims to summarise existing academic research related to the symptom profile of BN, the costs and burden imposed by the illness, barriers to the receipt of care, and the evidence base for available psychological treatments. As a consequence of well-documented difficulties in accessing evidence-based treatments for eating disorders, efforts have been made towards developing innovative, diverse channels to deliver treatment, with several of these attempting to harness the potential of digital platforms. In response to the increasing number of trials investigating the utility of online treatments, this paper provides a critical review of previous attempts to examine digital interventions in the treatment of eating disorders. The results of a focused literature review are presented, including a detailed synthesis of a knowledgeable selection of high-quality articles with the aim of providing an update on the current state of research in the field. The results of the review highlight the potential for online self-help treatments to produce moderately sized reductions in core behavioural and cognitive symptoms of eating disorders. However, concern is raised regarding the methodological limitations of previous research in the field, as well as the high rates of dropout and poor adherence reported across most studies. The review suggests directions for future research, including the need to replicate previous findings using rigorous study design and methodology, as well as further investigation regarding the utility of clinician support and interactive digital features as potential mechanisms for offsetting low rates of engagement with online treatments.

University students' use of mental health services: a systematic review and meta-analysis

BACKGROUND

International estimates suggest around a third of students arrives at university with symptoms indicative of a common mental disorder, many in late adolescence at a developmentally high-risk period for the emergence of mental disorder. Universities, as settings, represent an opportunity to contribute to the improvement of population mental health. We sought to understand what is known about the management of student mental health, and asked: (1) What proportion of students use mental health services when experiencing psychological distress? (2) Does use by students differ across health service types?

METHODS

A systematic review was conducted following PRISMA guidelines using a Context, Condition, Population framework (CoCoPop) with a protocol preregistered on Prospero (CRD42021238273). Electronic database searches in Medline, Embase, PsycINFO, ERIC and CINAHL Plus, key authors were contacted, citation searches were conducted, and the reference list of the WHO World Mental Health International College Student Initiative (WMH-ICS) was searched. Data extraction was performed using a pre-defined framework, and quality appraisal using the Joanna Briggs Institute tool. Data were synthesised narratively and meta-analyses at both the study and estimate level.

RESULTS

7789 records were identified through the search strategies, with a total of 44 studies meeting inclusion criteria. The majority of included studies from the USA (n = 36), with remaining studies from Bangladesh, Brazil, Canada, China, Ethiopia and Italy. Overall, studies contained 123 estimates of mental health service use associated with a heterogeneous range of services, taking highly variable numbers of students across a variety of settings.

DISCUSSION

This is the first systematic quantitative survey of student mental health service use. The empirical literature to date is very limited in terms of a small number of international studies outside of the USA; studies of how services link together, and of student access. The significant variation we found in the proportions of students using services within and between studies across different settings and populations suggests the current services described in the literature are not meeting the needs of all students.

The prevalence and risk factors of screen-based disordered eating among university students: a global systematic review, meta-analysis, and meta-regression

PURPOSE

The purpose of this review was to estimate the prevalence of screen-based disordered eating (SBDE) and several potential risk factors in university undergraduate students around the world.

METHODS

An electronic search of nine data bases was conducted from the inception of the databases until 1st October 2021. Disordered eating was defined as the percentage of students scoring at or above established cut-offs on validated screening measures. Global data were also analyzed by country, research measure, and culture. Other confounders in this review were age, BMI, and sex.

RESULTS

Using random-effects meta-analysis, the mean estimate of the distribution of effects for the prevalence of SBDE among university students (K = 105, N = 145,629) was [95% CI] = 19.7% [17.9%; 21.6%], I2 = 98.2%, Cochran's Q p value = 0.001. Bayesian meta-analysis produced an estimate of 0.24, 95% credible intervals [0.20, 0.30], τ = 92%. Whether the country in which the students were studying was Western or non-Western did not moderate these effects, but as either the mean BMI of the sample or the percentage of the sample that was female increased, the prevalence of SBDE increased.

CONCLUSIONS

These findings support previous studies indicating that many undergraduate students are struggling with disordered eating or a diagnosable eating disorder, but are neither receiver effective prevention nor accessing accurate diagnosis and available treatment. It is particularly important to develop ever more valid ways of identifying students with high levels of disordered eating and offering them original or culturally appropriate and effective prevention or early treatment.

LEVEL OF EVIDENCE

I, systematic review and meta-analysis.

Worldwide prevalence of DSM-5 eating disorders among young people

PURPOSE OF REVIEW

Eating disorders (anorexia nervosa, bulimia nervosa, binge eating disorder, and other eating disorders) affect young people worldwide. This narrative review summarizes key studies conducted on the prevalence of Diagnostic and Statistical Manual of Mental Disorders (DSM-5) eating disorders among young people in 2013-22.

RECENT FINDINGS

In Western settings, a substantial proportion of young people have reported an eating disorder. Overall, 5.5--17.9% of young women and 0.6-2.4% of young men have experienced a DSM-5 eating disorder by early adulthood. Lifetime DSM-5 anorexia nervosa was reported by 0.8-6.3% of women and 0.1-0.3% of men, bulimia nervosa by 0.8-2.6% of women and 0.1-0.2% of men, binge eating disorder by 0.6-6.1% of women and 0.3-0.7% of men, other specified feeding or eating disorders by 0.6-11.5% of women and 0.2-0.3% of men, and unspecified feeding or eating disorders 0.2-4.7% of women and 0-1.6% of men. Gender and sexual minorities were at particularly high risk. Emerging studies from Eastern Europe, Asia, and Latin America show similar high prevalences. During the COVID-19 pandemic, the incidence of eating disorders has still increased.

SUMMARY

Eating disorders are a global health concern among young people. Improved detection, management, and prevention methods are urgently needed.

Brain serotonin deficiency and fluoxetine lead to sex-specific effects on binge-like food consumption in mice

RATIONALE

Although pharmacotherapies are often effective in reducing binge eating in conditions such as bulimia nervosa and binge eating disorder, subsets of patients do not benefit sufficiently from existing treatments, and the reasons for treatment failure remain unclear.

OBJECTIVES

This study aimed to evaluate whether genetic reductions in brain serotonin influence binge eating and/or the ability of fluoxetine, a selective serotonin reuptake inhibitor, to reduce binge eating in mice.

METHODS

This study used a validated model of binge-like consumption of high-fat diet to compare binge-like food intake in control and fluoxetine-treated wild-type and serotonin-deficient mice from the tryptophan hydroxylase 2 (R439H) knock-in line. In addition, real-time PCR was used to evaluate potential genotype and sex differences in the effects of fluoxetine on gene expression in the raphe nucleus.

RESULTS

The results reveal that brain serotonin deficiency is sufficient to increase binge eating in males, but not females. However, while chronic fluoxetine reduced binge eating in both genotypes of males and in wild-type females, it failed to reduce binge eating in serotonin-deficient females. Transcriptional responses to chronic fluoxetine were also characterized by sex and genotype differences.

CONCLUSIONS

Overall, this study revealed significant sex differences in the effects of fluoxetine and brain serotonin deficiency on binge-like food intake and suggests that low brain serotonin could impact eating disorders both by promoting binge eating and by limiting the efficacy of fluoxetine to reduce binge eating.