Executive function performance in obesity and overweight individuals: A meta-analysis and review

Meta-analyses of executive function deficits in chemotherapy-treated rodent models

People diagnosed with cancer who undergo chemotherapy commonly encounter cognitive changes, particularly in executive functions (EFs). EFs support goal-directed behaviours, with EF deficits implicated in various neurocognitive impairments. We conducted five meta-analyses of the rodent models to investigate the impact of chemotherapy across five EF domains. A systematic search across PubMed, Web of Science, Scopus, and PsycINFO yielded 56 eligible papers. Our findings supported the clinical literature suggesting the selective impact of chemotherapy on different EF domains. Specifically, chemotherapy-treated animals performed significantly more poorly than controls in tasks assessing working memory, behavioural flexibility, and problem-solving, with no significant group differences in inhibition or attention. Subgroup analyses revealed that alkylating agents, antitumor antibiotics, and combination therapies were strongly associated with working memory deficits, whereas mitotic inhibitors were not. Rodent species, strain, age, sex, number of treatments, and time of behavioural assessment since the end of treatment did not moderate the drug effect on any assessed EF domains. To increase the generalisability and translational validity of the results, the overall reporting quality of animal studies needs to be improved with more details on randomisation, blinding, sample sizes, and criteria for animal exclusions.

Inhibitory control is related to fecal short-chain fatty acid concentrations in adults with overweight and obesity

Obesity is a pro-inflammatory condition with negative effects on executive functioning. Increased inflammation dysregulates gastrointestinal homeostasis and alters microbiota community composition. The gut microbiota produce immunomodulatory short-chain fatty acids (SCFA) that have been related to cognition in obesity, but the neural effects are not explored. Here, we hypothesized that greater fecal SCFA would be positively related to neuroelectric markers of inhibitory control and conflict monitoring in obesity. A cross-sectional cohort of 87 adults (35 ± 6 years, 53 females) with overweight and obesity (BMI = 32 ± 6 kg/m2) provided fresh fecal samples and participated in cognitive testing to assess response inhibition and conflict monitoring with electroencephalographic recording. Linear regressions, controlling for age, sex, BMI, and energy-adjusted dietary fiber intake, revealed positive relationships between NoGo N2 mean amplitude and fecal SCFA concentrations. Linear discriminant analysis effect size (LEfSe) revealed 16 amplicon sequence variants differentially abundant between high and low butyrate groups with Roseburia and Adlercreutzia individually related to NoGo N2 mean amplitude in MaAsLin2 modeling. Thus, greater fecal SCFA concentrations and SCFA producing microbiota (i.e., Roseburia) were related to markers of superior conflict monitoring in the NoGo task when adjusting for key covariates. These data highlight key associations between bacterial derived gut signaling molecules and neural regulation in cognitive domains particularly relevant to weight status that warrant further investigation.

The Ubiquity of Cognitive Impairment in Human Illness: a Systematic Review of Meta-Analyses

OBJECTIVE

Cognitive dysfunction occurs in many neurological, psychiatric, and other health conditions. This review aimed to characterize the breadth and degree of cognitive morbidity associated with varied health conditions.

METHOD

We systematically reviewed Medline, EMBASE, and Cochrane databases for meta-analyses of cognitive dysfunction associated with any health condition. Meta-analyses were eligible if they reviewed studies that compared patients with health conditions to healthy controls on cognitive testing and provided effect sizes.

RESULTS

We found 91 meta-analyses for 94 health conditions. Among >800,297 participants, healthy controls out-performed clinical participants in every condition on cognitive testing. Mean effect sizes ranged from -2.02 to -0.00 across conditions and were ≤ -0.5 on average, denoting moderate to very severe dysfunction for 41% of them.

CONCLUSIONS

Cognitive dysfunction is ubiquitous in medicine. Both primary care and specialist physicians likely treat patients with cognitive dysfunction. Depending on its severity, cognitive dysfunction can affect treatment adherence, everyday functioning, quality of life, and the capacity to provide informed consent for treatment. These findings highlight the transdiagnostic nature of cognitive symptoms and the potential value of establishing collaborations between physicians and clinical neuropsychologists to integrate cognitive assessment into patient care. Even brief assessments can identify cognitive deficits that likely affect treatment adherence and functional outcomes.

Noshing on Chocolate, I Can Do That: Increased Chocolate Consumption in the Chocolate-Modified Bogus Taste Test With Better and Not Worse Inhibitory Control

BACKGROUND

Chocolate is the most craved energy-dense food. Yet, most individuals can limit their chocolate consumption. Here, we investigate the cognitive mechanisms underlying chocolate consumption in a chocolate bogus taste test in a cross-sectional experimental design.

METHOD

High chocolate cravers abstained from chocolate for a week, followed by a virtual reality chocolate exposure with biometric trajectory recordings of their stopping responses and an ad-libitum bogus taste test of spontaneous chocolate intake. A single-target implicit association task and a computerised stop-signal task served as unstandardised control tasks 1-2 days before chocolate intake.

RESULTS

Associations of parameters from all tasks with chocolate intake were small (|r| < 0.23). Elastic net models misestimated food intake by min. 160 kcal (generalisation: 180 kcal) and feature selection was only possible with L1 penalty. At the group level, participants showed a more controlled and delayed movement towards chocolate relative to neutral cues, evidenced by lower peak acceleration and peak velocity and faster stopping latency.

DISCUSSION

The findings demonstrate the complex cognitive-behavioural underpinnings of food intake, food craving and abstinence.

Effects of the DailyColors™ polyphenol supplement on serum proteome, cognitive function, and health in older adults at risk of cognitive and functional decline

The Mediterranean diet is associated with reduced mortality and cognitive decline, largely due to its polyphenol content. However, Western populations often do not meet recommended fruit and vegetable intakes. Polyphenols exert anti-inflammatory effects and may influence extracellular vesicle (EV) dynamics. DailyColors™ is a polyphenol-rich blend inspired by this dietary pattern, containing extracts from 16 fruits, vegetables, and herbs. This 60-day, double-blind, placebo-controlled, randomised trial involved 150 UK adults aged 50+ with a BMI ≥ 25, recruited to complete cognitive and physical fitness assessments via the PROTECT-UK online platform. Participants received either a medium (750 mg) or high (2000 mg) dose of DailyColors™ (∼300 mg and ∼750 mg polyphenols, respectively) or a placebo. A sub-group (n = 15 per group) underwent additional assessments, including blood pressure measurements, characterisation of circulating EVs and tandem-mass-tagged serum proteomics. Significant cognitive benefits were observed, with improvements in reaction time for the high-dose group and accuracy for both active supplement groups. The high-dose group also showed significant physical fitness gains on the Timed Stand test (P < 0.001). All groups significantly improved on the Chair Stand test. Proteomic analysis showed significantly reduced serum protein expression in immune and pre-β1-HDL pathways, suggesting anti-inflammatory effects. Pre-β1-HDL proteins are typically elevated in obesity; their reduction suggests a reversal of this effect. No significant changes were noted in EV concentration or size. DailyColors™ supplementation, may enhance cognitive function, physical fitness, and systemic health in older, overweight adults. These findings warrant further investigation in larger trials.

Role of early life adversities in inflammation-related neuropsychiatric comorbidity in obesity

A growing body of data highlights the key role of adiposity-related inflammation in the development of neuropsychiatric comorbidity in obesity. Nevertheless, despite similar levels of inflammation, only a subgroup of obese subjects is afflicted with neuropsychiatric symptoms, suggesting the contribution of additional vulnerability factors. In light of previous work suggesting the involvement of early life adversity (ELA), this study aims to determine whether ELA promotes the emergence of inflammation-related neuropsychiatric symptoms in a sample of obese subjects. Eighty-two adults afflicted with obesity (BMI > 30 kg/m2) and twenty-one lean individuals (BMI < 25 kg/m2) were recruited. Depressive symptoms, fatigue and neurobehavioral symptoms were assessed through semi-structured interviews and validated self-reports. ELA was measured using the Childhood Trauma Questionnaire (CTQ). Systemic inflammation was determined through serum concentrations of high-sensitivity C-reactive protein (hsCRP). In the whole population under study, hsCRP concentrations were significantly associated with neuropsychiatric symptoms, consistent with the increased prevalence of neuropsychiatric comorbidity in obese subjects. Significant associations were also found between ELA severity and neuropsychiatric symptoms. Although they did not influence hsCRP levels, ELA antecedents in obese subjects were associated with more marked mood, fatigue and cognitive symptoms. Among ELA, sexual abuse was the only significant predictor of the association between hsCRP levels and neuropsychiatric comorbidity in obesity. These findings support the hypothesis that ELA represents a potent vulnerability factor for the development of neuropsychiatric comorbidity in obese subjects with chronic inflammation.

[Impact of body composition and psychological state on executive functions in individuals with obesity]

BACKGROUND

This study aimed to examine the relationship between anthropometric and psychological variables and executive functions in individuals with obesity.

METHOD

Adults with obesity were recruited in Alicante (Spain). Participants underwent interviews to collect sociodemographic data (sex, age, educational level, marital status, and employment status) and anthropometric assessments measuring weight, body mass index, visceral fat, fat mass, and muscle mass. Psychological evaluations were carried out using the DASS-21. Executive functions were assessed through the M-WCST (cognitive flexibility), WAIS-IV (working memory), TMTA (processing speed), and TMTB (inhibitory control).

RESULTS

The sample comprised 48 participants (52% female) with a mean age of 47.58 years. Most participants had secondary education, were married, and employed. Women exhibited higher values in weight, body mass index, and fat mass (% and kg). Multiple linear regression analyses revealed that anthropometric variables -weight, body mass index, visceral fat, fat mass, and muscle mass- significantly influenced performance on working memory, processing speed, and inhibitory control performance. Additionally, anxiety levels were associated with cognitive flexibility and working memory, while depression levels were linked to inhibitory control.

CONCLUSIONS

Anthropometric variables -weight, body mass index, visceral fat, fat mass, and muscle mass- are associated with variations in executive function performance, particularly in working memory, processing speed, and inhibitory control. Psychological states -anxiety and depression- are related to specific aspects of executive functioning.

How Is the Digital Age Shaping Young Minds? A Rapid Systematic Review of Executive Functions in Children and Adolescents with Exposure to ICT

Objectives: This review assesses how daily exposure to Information and Communication Technologies (ICTs) affects executive functions in children and adolescents and explores the roles of parents in mitigating potential negative impacts on cognitive development and emotional regulation. Methods: Following PRISMA guidelines, a systematic search was conducted from 2022 to 2024 using PubMed, Scopus, and Cochrane Library. The study criteria included cohort studies, randomized controlled trials (RCTs), quasi-RCTs, and systematic reviews. Data extraction and risk-of-bias assessments were performed using ROBIS and ROBINS-E tools. Due to the heterogeneity of the results, a narrative synthesis was carried out. Results: Ten studies were included for analysis, comprising a total of 231,117 children from nine countries on three continents. Most studies indicated that excessive ICT exposure negatively affects executive functions, particularly working memory, inhibitory control, cognitive flexibility, and attention. Adverse effects were linked to increased screen time, poor sleep quality, and multitasking. However, two studies found no significant association, highlighting the influence of contextual factors like socioeconomic status, parental mediation, and screen content type. Shared ICT use with parents or siblings appeared to reduce negative effects. Conclusions: Excessive ICT exposure is associated with impaired executive function development in children and adolescents. Parental supervision and structured ICT use may mitigate risks. Future research should investigate moderating factors, such as socioeconomic status and ICT content, to develop guidelines for healthy digital engagement in youth.

Association of adiposity evaluated by anthropometric and bioelectrical impedance analysis measures with cognitive performance in the ELSA-Brasil study

BACKGROUND

While midlife obesity is linked to cognitive decline, this association is inconsistent in older adults, possibly due to the limitations of body mass index (BMI) in accurately assessing adiposity at older ages. Most studies focused on White or Asian populations, did not include other adiposity measures besides BMI, adjusted the analyses for mediators, and did not investigate potential subgroup-specific associations. We compared the associations of adiposity measured by anthropometrical and bioelectrical impedance analysis (BIA) with cognitive performance in a diverse population, examining modifications by age, sex, and race, and investigating the mediating effects of obesity-related comorbidities.

METHODS

Cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) cohort (n = 12,636). Adiposity was evaluated using BMI, waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), and body fat percentage (BFP). A composite global cognition score was derived from immediate, delayed recall, and word recognition word list, phonemic and semantic verbal fluency, and trail-making tests. Adjusted linear regression models were used to investigate associations. We included an interaction term in the regression models to verify if age, sex, and race were modifiers of these associations and used causal mediation methods to assess the mediating role of obesity-related comorbidities.

RESULTS

Among 10,725 participants [mean age (SD): 58.9 (8.6) years; 55.8% women, 54.4% White], larger WHR and WHtR were associated with worse global cognitive performance. These associations were not modified by age, sex, or race. An association of BFP with cognition was observed only in younger adults. Mediation analysis identified only indirect effects of these adiposity measures on cognitive performance and no direct effects.

CONCLUSION

WHR and WHtR were more consistently associated with cognitive performance than BMI. BIA measures of adiposity were associated with cognition only in younger adults. Obesity-related comorbidities fully mediated the associations of adiposity with cognition.

Gamified Interventions for Obesity and Overweight Prevention and Treatment: A Scoping Review

BACKGROUND

Obesity and overweight affect approximately 30% of the world's population. These conditions present a global challenge, as they lead to morbidity and the development of chronic diseases such as type 2 diabetes, cardiovascular disease, and cancer. Various strategies are available to address obesity and overweight. Nonpharmacological strategies include therapeutic patient education, which employs novel approaches to inform and engage patients, including gamification, the integration of gaming elements into nongaming contexts.

PURPOSE

This scoping review aimed to explore, map, and investigate gamified tools for obesity and overweight prevention and treatment, as well as their effectiveness.

METHODS

The review was conducted in accordance with the JBI guidelines for scoping reviews and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) checklist. Searches were conducted in MEDLINE, CINAHL, PsycInfo, Embase, Scopus, and the Cochrane Library.

RESULTS

Six articles, primarily from the United States and published within the last eight years, were included in the review. Three main themes emerged: the use of gamification to reduce weight, the use of gamification to encourage physical activity, and the use of gamification to facilitate behavior change (adoption of a healthy diet).

CONCLUSION

Further research should be conducted on the use of gamification to prevent and treat obesity and overweight, because it seems to be effective in certain subpopulations and for reaching specific outcomes.

Neural and Behavioral Correlates of Binge Eating in 9- to 10-Year-Old Children

OBJECTIVE

This observational study compared children with and without binge eating (BE) on biobehavioral measures of reward responsiveness, inhibitory control, and emotion processes, while accounting for the impact of weight.

METHOD

Children aged 9 to 10 years completed the baseline wave of the Adolescent Brain Cognitive Development Study (316 with BE; 7,681 without BE [no-BE]). The prevalence of binge-eating disorder in the BE group was 17.0%; clinically significant internalizing and externalizing symptoms were endorsed by 8.5% and 4.5% of the sample, respectively. The monetary incentive delay (MID) task, stop signal task (SST), and emotional N-Back (EN-Back) task were administered during neuroimaging. Analyses assessed effects of group (BE vs no-BE) on task performance and corresponding neural signal in regions of interest (ROIs). Weight status was evaluated as a covariate and as a moderator of effects.

RESULTS

Adjusting for weight status, the BE group (vs no-BE) group showed lower activation during anticipation of reward, specifically large reward (vs no reward), in the composite ROI consisting of the dorsal striatum, nucleus accumbens, orbital frontal gyrus, amygdala, and insula. Groups did not differ significantly in other behavioral or neural outcomes. No interactions between group and weight status were observed.

CONCLUSION

Blunted anticipatory responses to monetary reward were associated with binge eating during peri-adolescence and may play a role in binge eating pathophysiology. Results challenge prior findings in BE that may be confounded by weight, and highlight the importance of future prospective research across binge-eating disorder stage of illness.

PLAIN LANGUAGE SUMMARY

Binge eating disorder, the most common eating disorder, is associated with several negative psychosocial consequences. This study used data from the Adolescent Brain Cognitive Development (ABCD) Study and compared children (ages 9-10) with and without binge eating on neurobiological and behavioral measures of reward responsiveness, inhibitory control, and emotion processes. Children with binge eating showed lower neural activation during anticipation of reward, specifically large reward, compared to youth without binge eating. These findings suggest that blunted anticipatory response during peri-adolescence may play a role in binge eating pathophysiology.

Body Mass Index and subjective cognitive decline among cancer survivors in the US: a cross-sectional analysis of a nationally representative survey

OBJECTIVE

Despite the strong evidence suggesting significant relationships between Body Mass Index (BMI) and cognitive functioning in the general population, there is a dearth of research on this potential association in the cancer survivor sub-population. Therefore, utilizing a nationally representative sample, the current study seeks to examine the cross-sectional association between BMI and subjective cognitive decline (SCD) in adult cancer survivors in the US.

METHODS

The 2020, 2021, and 2022 Behavioral Risk Factor Surveillance System (BRFSS) surveys were used for the analysis. Logistic regression was performed to examine the odds of SCD in a sample of 20,739 cancer survivors, controlling for age, sex, race/ethnicity, marital status, level of education, employment status, general health status, and cigarette smoking status. All analyses were weighted to account for the complex study design and to produce nationally representative population estimates.

RESULTS

The prevalence of SCD among cancer survivors in this study was approximately 15%. Significant associations between BMI and SCD were found; compared to cancer survivors with normal weight, the odds of experiencing SCD were significantly greater for those with overweight (adjusted odds ratio [AOR] 1.22, 95% confidence interval [CI] 1.01-1.49) and obesity (AOR  1.24, 95%CI 1.02-1.51).

CONCLUSION

Among cancer survivors in this study, unhealthy weight is associated with a higher risk of subjective cognitive decline. Underscoring the need for evidence-based interventions that support the cognitive health of adult cancer survivors, with a focus on those with unhealthy weight.

How individual BMI affected general cognitive ability in young adults: a moderated chain mediation model

Objective

With the rising global obesity rates, increasing research has been directed toward understanding how obesity affects cognitive ability in young adults. This study aims to explore the impact of body mass index (BMI) on general cognitive ability and how sleep quality and impulsive trait mediate this relationship.

Methods

A total of 1,205 young adults from Human Connectome Project(HCP) project were included, and questionnaires and cognitive assessment tools were conducted.

Results

BMI was negatively correlated with general cognitive ability, with sleep quality and impulsive trait acting as chain mediators between BMI and general cognitive ability. Additionally, gender moderated the effect of BMI on sleep quality, with this effect being more pronounced in female young adults.

Conclusion

This study not only provided new insights into the impact of BMI on general cognitive ability in young adults but also offered an important perspective on how sleep quality and impulsive trait influenced this process. These findings provide a scientific basis for preventive measures against obesity and cognitive impairment in young adults.

The effects of nuts intake on cognitive and executive function in obese children: a randomized clinical trial

BACKGROUND

Childhood obesity is a significant, worldwide challenge disrupting various body organs including the brain. Studies suggest that nuts, rich in nutritional compounds, can improve cognitive function. This study aimed to investigate the effects of consuming nuts on improving cognitive and executive function in obese children.

METHODS

In this randomized parallel clinical trial, ninety 8 to 10-year-old girls with obesity were divided into intervention (30 g of nuts/daily) and control groups (no nuts) for 8 weeks. Furthermore, the Wechsler Four (WISC-IV) questionnaire assessed children's cognitive function, and executive function was assessed by the behavior rating inventory of executive function (BRIEF) parental questionnaire. Linear mixed-effect models were done to survey the effects of nut intake on cognitive and executive function.

RESULTS

Forty people with a mean age of 9 ± 0.7 years from each group cooperated to the end of the study. The intervention group showed a significant improvement in the total Wechsler score (differences: 23.1, 95% CI: 17.5, 28.7; PTime×Group < 0.001) and total BRIEF score (differences: - 16.5, 95% CI: - 29.4, - 3.5; PTime×Group < 0.05) compared to the control group. Moreover, other components of the Wechsler and BRIEF tests including picture completion, picture concept, block design, object assembly, short-term memory, digit span, inhibition, displacement, initiation, and organization were significantly improved in the nuts group compared to the control group after the 8th weeks.

CONCLUSION

These results underline the potential of nut consumption as a dietary intervention to improve cognitive function over an eight-week period, highlighting its role in supporting brain health and cognitive development of obese children.

Decoding the impact of negative physical self-perception on inhibitory control ability from theta and beta rhythms

Previous studies have found inhibitory control differences between obese individuals and those of normal weight. However, some normal-weight individuals with high negative physical self-perception on the fatness subscale show restrictive eating behaviors and attentional bias toward high-calorie food, potentially influencing these differences. We collected behavioral and electroencephalography data using a novel inhibitory control task. Results showed that individuals with high negative physical self-perception on the fatness subscale exhibited significantly greater restraint eating behavior compared to controls. Both theta and beta power differed between groups, with higher theta power in the high negative physical self-perception on the fatness subscale group than in the obese group and more negative beta power in the high negative physical self-perception on the fatness subscale group compared to both other groups. Theta power was greater in no-go than go conditions, while beta power was more negative in response to high-calorie versus low-calorie food stimuli. Importantly, theta power successfully decoded go/no-go conditions across all groups using multivariate pattern analysis, while beta power distinguished these conditions only in the negative physical self-perception on the fatness subscale and control groups. These findings suggest that theta and beta power, along with multivariate pattern analysis, can reliably distinguish inhibitory control ability among the three groups, highlighting the importance of considering negative physical self-perception on the fatness subscale when assessing inhibitory control differences between normal-weight and obese individuals.

Interrupting sitting with moderate-intensity physical activity breaks improves cognitive processing speed in adults with overweight and obesity: Findings from the SITLess pilot randomized crossover trial

INTRODUCTION

Prolonged sitting can acutely reduce working memory (WM) in individuals with overweight and obesity (OW/OB) who show executive function deficits. Interrupting prolonged sitting with brief PA bouts may counter these effects. However, the benefits of such interventions on behavioral and neuroelectric indices of WM and whether neurocognitive responses are associated with postprandial glycemic responses in young and middle-aged adults with OW/OB remain unknown. To address this gap, this study examined the acute effects of interrupting three-hour prolonged sitting every 30 min with 3.5-min moderate-intensity physical activity (MPA) bouts (MPA + SIT condition) relative to sedentary social interaction condition (SOC + SIT) on behavioral measures of WM and the P3b component of event-related potentials (ERP) in young and middle-aged adults with OW/OB.

METHOD

Nineteen adults with OW/OB (63 % females; 29.9 ± 7.5 years; BMI = 30.0 ± 3.64 kg*m-2) were included in the SITLess pilot randomized crossover trial. Choice RT and WM were measured before, after, and four times during each condition with 1- and 2-back letter tasks. They were expressed as the incremental area under the curve (iAUC). Choice RT was expressed as d-prime, target, and nontarget accuracy, and RT on the 1-back and nontarget RT on the 2-back task. WM was expressed as d-prime, target accuracy, and RT on the 2-back task. The amplitude of the P3b-ERP component was used to measure attentional resource allocation during both tasks; the P3b-ERP fractional area latency measured cognitive processing before and after each condition. Two-hour postprandial glycemic responses (expressed as iAUC) were measured using an oral glucose tolerance test (OGTT). Time (pre, post) x Condition (MPA + SIT vs. SOC + SIT) interactions and the main effect of Condition (iAUCs) were tested using Linear Mixed Models.

RESULTS

No significant intervention effects on glucose were noted (p = 0.74). Compared to SOC + SIT, MPA + SIT resulted in shorter 1-back target P3b latency (F(1, 17.0) = 5.14, p = 0.037; Mdiff = -9.77, SE = 4.31 ms, 95%CI: -18.9, -0.68) at post-test. No effects on behavioral measures were noted (ps ≥ 0.06). However, the between-condition difference in 1-back P3b latency correlated positively with the between-condition difference in RTs on 1-back;shorter P3b latency was related to shorter RTs in the MPA + SIT relative to SOC + SIT (r = 0.65 and 0.55 for target and nontarget trials, ps ≤ 0.02).

CONCLUSION

Interrupting sitting with short MPA bouts can enhance some aspects of cognitive processing in adults with OW/OB. Future studies are needed to better understand behavioral responses to interrupting prolonged sitting with MPA bouts and the underlying mechanisms.

A comparative study of cognitive function and reaction time in obese and non-obese adults

OBJECTIVE

Obesity may negatively affect the physical health and cognitive functions of individuals and delay their reaction time to stimuli. However, the association among obesity, cognitive functions, and reaction times is yet to be fully elucidated. The aim of this study was to assess the effect of obesity on cognitive functions and visual and auditory reaction times in adults.

METHODS

Data of 100 participants (50 obese and 50 normal) were analyzed in the study. Anthropometric parameters and 24-h dietary recall data were recorded. The Montreal Cognitive Assessment (MoCA) was used to evaluate the cognitive functions, Simple Reaction Time Task (SRTT)-Visual and SRTT-Auditory were used to assess visual and auditory reaction times of the participants, respectively.

RESULTS

The mean MoCA score of the obese was significantly lower than normal (17.46 and 25.22, respectively; p < 0.001). In addition, the mean auditory (p < 0.001) and visual (p < 0.05) reaction times of obese were significantly longer than normal. Similarly, this condition was also observed for the fastest and lowest values of auditory and visual reaction times. Additionally, obesity caused a decrease in the MoCA score (β = -0.762; p < 0.001) and delayed visual (β = 0.423; p < 0.001) and auditory (β = 0.590; p < 0.001) reactions. The negative effect of obesity was maintained after controlling for potential factors (MoCA, β = -0.594; p < 0.001; SRTT-Auditory, β = 0.409; p < 0.01; SRTT-Visual, β = 0.330; p < 0.05).

CONCLUSION

Obese participants showed worse cognitive, auditory and visual performance. Additional research will be necessary in the future to shed light on the fundamental mechanisms involved.

Intermittent fasting and neurodegenerative diseases: Molecular mechanisms and therapeutic potential

Neurodegenerative disorders are straining public health worldwide. During neurodegenerative disease progression, aberrant neuronal network activity, bioenergetic impairment, adaptive neural plasticity impairment, dysregulation of neuronal Ca2+ homeostasis, oxidative stress, and immune inflammation manifest as characteristic pathological changes in the cellular milieu of the brain. There is no drug for the treatment of neurodegenerative disorders, and therefore, strategies/treatments for the prevention or treatment of neurodegenerative disorders are urgently needed. Intermittent fasting (IF) is characterized as an eating pattern that alternates between periods of fasting and eating, requiring fasting durations that vary depending on the specific protocol implemented. During IF, depletion of liver glycogen stores leads to the production of ketone bodies from fatty acids derived from adipocytes, thereby inducing an altered metabolic state accompanied by cellular and molecular adaptive responses within neural networks in the brain. At the cellular level, adaptive responses can promote the generation of synapses and neurons. At the molecular level, IF triggers the activation of associated transcription factors, thereby eliciting the expression of protective proteins. Consequently, this regulatory process governs central and peripheral metabolism, oxidative stress, inflammation, mitochondrial function, autophagy, and the gut microbiota, all of which contribute to the amelioration of neurodegenerative disorders. Emerging evidence suggests that weight regulation significantly contributes to the neuroprotective effects of IF. By alleviating obesity-related factors such as blood-brain barrier dysfunction, neuroinflammation, and β-amyloid accumulation, IF enhances metabolic flexibility and insulin sensitivity, further supporting its potential in mitigating neurodegenerative disorders. The present review summarizes animal and human studies investigating the role and underlying mechanisms of IF in physiology and pathology, with an emphasis on its therapeutic potential. Furthermore, we provide an overview of the cellular and molecular mechanisms involved in regulating brain energy metabolism through IF, highlighting its potential applications in neurodegenerative disorders. Ultimately, our findings offer novel insights into the preventive and therapeutic applications of IF for neurodegenerative disorders.

Examining Food-Specific and General Inhibitory Control and Working Memory as Moderators of Relations Between Emotion Regulation Difficulties and Eating Pathology in Adults With Overweight/Obesity: A Preregistered, Cross-Sectional Study

OBJECTIVE

Empirical research and theory support the interaction of executive functions (e.g., inhibitory control, working memory) and emotion regulation in guiding goal-oriented behavior; however, applications to eating pathology (e.g., binge eating) are limited. Such research is scant with adults with overweight/obesity (AwO/O), a population reporting high levels of binge eating, emotion regulation difficulties, and deficits in inhibitory control and working memory. We tested interactions between emotion regulation and executive functioning in relation to eating pathology in AwO/O while considering stimuli-specific deficits (e.g., food-specific deficits) in behavioral task performance.

METHOD

AwO/O (N = 204; MBMI = 32.11; Mage = 38.30 [SD = 12.16]) completed a preregistered, online study assessing demographics and emotion regulation difficulties (Difficulties in Emotional Regulation Scale), inhibitory control (go/no-go task, food and general stimuli), working memory (N-Back Task, food and general stimuli), binge eating (Binge Eating Scale), and disordered eating (Eating Disorder Examination-Questionnaire).

RESULTS

There was limited evidence of moderation in models examining food-specific and general inhibitory control and working memory, emotion regulation difficulties, and binge eating. Preliminary support was found for emotion regulation difficulties to be more strongly associated with more disordered eating in AwO/O reporting more food-specific and general working memory deficits. Consistent, positive associations between emotion regulation difficulties and eating pathology were observed.

CONCLUSIONS

Among adults with AwO/O, emotion regulation difficulties are closely related to eating pathology, regardless of performance on working memory and inhibitory control tasks. Clinicians and researchers working with AwO/O may consider how emotion regulation difficulties and working memory deficits work together to influence disordered eating.

The Impact of Acute Aerobic Exercise on General and Food-Related Inhibitory Function Among Young Adults with Obesity: An Event-Related Potential (ERP) Study

Backgrounds and Objectives: Obesity presents a significant global public health challenge and is associated with declines in both general and food-related inhibitory control, crucial for maintaining a healthy weight and preventing obesity progression. An increasing body of research suggests that acute aerobic exercise may improve inhibitory function. However, the effects and underlying mechanisms of acute aerobic exercise on both general and food-related inhibition in obese adults remain unclear. This study aimed to explore the potential impacts and underlying neuroelectronic mechanisms of a single session of aerobic exercise at varying intensities on general and food-related inhibitory functions among young adult males with obesity. Design: A within-subject design comprising three sessions (control, low-intensity exercise, moderate-intensity exercise) × three picture types (high-calorie food, low-calorie food, neutral picture) was employed. Methods: Eighteen young adult males with obesity [body mass index (BMI): 34.60 ± 4.21 kg/m2, aged 24.50 ± 5.13 years (Mean ± SD)] were recruited. They participated in three intervention sessions: acute aerobic exercise at low [40-50% maximal Heart Rate (HRmax)], moderate (65-70% HRmax), and a control session (sitting rest), separated by five-day intervals in a counterbalanced order. Following each session, participants performed a food-related Go/No-go task, and EEG recordings (N2 and P3 components) were conducted within 15 min. Results: Moderate-intensity exercise elicited larger N2 amplitudes compared to the control session across different picture types and task conditions. However, there was no significant effect on behavioral indicators or P3 amplitude across sessions. Additionally, food stimuli (both high- and low-calorie) resulted in lower No-go accuracy and smaller N2 amplitudes compared to neutral stimuli. Conclusions: Acute moderate-intensity exercise might influence general and food-related inhibitory function in obese individuals at the neuroelectric stage, potentially by enhancing attentional resources for managing cognitive control and conflict detection. Moreover, reduced N2 amplitudes and No-go accuracy in response to food stimuli compared to non-food stimuli indicate a diminished ability to allocate attentional and neural resources to manage food-related conflicts. However, due to the relatively small sample size, caution is advised when generalizing these findings to the broader population. The pilot test indicated that obese participants had difficulty sustaining high-intensity exercise at 80-90% of their maximum heart rate for a continuous or 20 min period, highlighting potential challenges in exercise adherence at high intensities within this population. Future research is needed to utilize interdisciplinary approaches and multimodal technologies to clarify how exercise influences food-related cognition, appetite regulation, and brain mechanisms in obesity, aiming to better contribute to the prevention and treatment of obesity.

The effect of exercise intervention on inhibitory function in obese and overweight children and adolescents: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Obese and overweight children and adolescents exhibit significant deficits in inhibitory function compared to their typical-weight peers. There is a high variability in the effectiveness of exercise interventions on inhibitory function in obese and overweight children and adolescents, and clinical protocols lack consistency. This study aims to systematically review the effects of exercise interventions on inhibitory function in obese and overweight children and adolescents.

METHODS

A systematic search was conducted on Web of Science, PubMed, Cochrane Library, EBSCO, WanFang Database, and China Knowledge Resource Integrated Database (CNKI) to gather randomized controlled trials (RCTs) examining the impact of exercise interventions on inhibitory function in obese and overweight children and adolescents. The search covered publications from January 2000 to January 8, 2024. Two researchers independently conducted a meta-analysis, screening the literature, extracting information, and assessing the methodological quality of the included studies.

RESULTS

The analysis included 24 randomized controlled trials (RCTs) with a total of 1,247 participants. The meta-analysis showed that post-intervention improvements in inhibitory function were significantly greater in the experimental group compared to the control group (SMD = -0.65, 95% CI = -1.01 to -0.29, p < 0.01), indicating a medium effect size. Subgroup analyses indicated that open motor skills (SMD = -0.73, 95% CI = -1.20 to -0.27, p < 0.01), moderate intensity (SMD = -0.80, 95% CI = -1.37 to -0.23, p < 0.01), and long-term regular exercise (SMD = -1.04, 95% CI = -1.47 to -0.62, p < 0.01) were significantly more effective than controls in improving inhibitory function. Both small exercise (SMD = -1.60, 95% CI = -2.25 to -0.94, p < 0.01) and large exercise volume (SMD = -0.85, 95% CI = -1.33 to -0.37, p < 0.01) outperformed the control group. Additionally, Stroop, Flanker, and Go/No-go tasks (SMD = -0.88, -0.62, 0.73, 95% CI = -1.43 to -0.32, -1.09 to -0.15, 0.20 to 1.25, p < 0.01) effectively assessed inhibitory function in obese and overweight children and adolescents.

CONCLUSION

Exercise can improve the inhibitory function of obese and overweight children and adolescents. The effectiveness of this intervention is influenced by exercise type, intensity, and duration. Long-term regular exercise involving open motor skills and moderate intensity yields better results in enhancing the inhibitory function of obese and overweight children and adolescents.

SYSTEMATIC REVIEW REGISTRATION

The protocol of this systematic review was registered with INPLASY. The protocol ID was INPLASY202450061.

Cerebellocerebral connectivity predicts body mass index: a new open-source Python-based framework for connectome-based predictive modeling

BACKGROUND

The cerebellum is one of the major central nervous structures consistently altered in obesity. Its role in higher cognitive function, parts of which are affected by obesity, is mediated through projections to and from the cerebral cortex. We therefore investigated the relationship between body mass index (BMI) and cerebellocerebral connectivity.

METHODS

We utilized the Human Connectome Project's Young Adults dataset, including functional magnetic resonance imaging (fMRI) and behavioral data, to perform connectome-based predictive modeling (CPM) restricted to cerebellocerebral connectivity of resting-state fMRI and task-based fMRI. We developed a Python-based open-source framework to perform CPM, a data-driven technique with built-in cross-validation to establish brain-behavior relationships. Significance was assessed with permutation analysis.

RESULTS

We found that (i) cerebellocerebral connectivity predicted BMI, (ii) task-general cerebellocerebral connectivity predicted BMI more reliably than resting-state fMRI and individual task-based fMRI separately, (iii) predictive networks derived this way overlapped with established functional brain networks (namely, frontoparietal networks, the somatomotor network, the salience network, and the default mode network), and (iv) we found there was an inverse overlap between networks predictive of BMI and networks predictive of cognitive measures adversely affected by overweight/obesity.

CONCLUSIONS

Our results suggest obesity-specific alterations in cerebellocerebral connectivity, specifically with regard to task execution. With brain areas and brain networks relevant to task performance implicated, these alterations seem to reflect a neurobiological substrate for task performance adversely affected by obesity.

Acute immune system activation exerts time-dependent effects on inhibitory control: Results of both a randomized controlled experiment of influenza vaccination and a systematic review and meta-analysis - ISPNE 2024 Dirk Hellhammer Award

Although coming down with an illness or receiving a vaccine are both common experiences, the influence of such acute immune system activations on cognitive processes, such as inhibitory control, has received relatively little attention. We addressed that issue by assessing the effects of acute immune system activation on inhibitory control in a randomized controlled experiment, and by conducting a meta-analysis of similar studies in humans. In our experiment, we found-somewhat surprisingly-that influenza vaccination improved performance on both of our inhibitory control outcomes (i.e., stop-signal reaction times and flanker interference effects). At the meta-analytic level, we found that at a short delay (1.5-4 hours post-injection) between immune activation and inhibitory control assessment, such activation impaired multiple forms of inhibitory control, whereas after a longer delay (e.g., > 18 hours post-injection), such activation improved inhibitory control-consistent with our experiment. Moreover, proinflammatory cytokine activity predicted poorer interference control but better response inhibition, even with a long delay between injection and testing. Together, these results highlight nuanced, time-dependent, and-perhaps-multiple-mechanism-driven effects of acute immune system activity on inhibitory control.

Acute ketone monoester supplementation in young adults: modulating metabolic and neurocognitive functions across body weights

This study investigated the acute effects of ketone monoester on metabolic and neurocognitive indicators and underlying metabolism-brain-cognition interactions among young adults of healthy weight (HW) and those with overweight/obesity (OW). Forty participants were divided into two groups: HW (n = 20, age 23.80 ± 3.96 years, body mass index (BMI) 21.49 ± 1.80 kg/m2) and OW (n = 20, age 22.00 ± 2.13 years, BMI 28.23 ± 3.48 kg/m2). Each participant completed two trials (ketone monoester vs. placebo, 395 mg/kg dose) in a randomized order. Metabolic indicators (blood beta-hydroxybutyrate (BHB) and glucose) and neurocognitive function (causal density via functional near-infrared spectroscopy and cognitive interference via the Stroop task) were measured at baseline, 30 min, and 90 min post-supplementation. A chain mediation model was constructed to test the indirect effects of BHB level on cognitive interference through mediators like blood glucose and causal density. In the linear mixed models, significant effects were observed for trial (β = -0.92, 0.20, -0.04, 25.53) and assessment time (β = 0.50, -0.14, 0.09, -62.88) in BHB, glucose, causal density, and cognitive interference (p < 0.05), but not for group factors. Compared to OW, the effects of ketone monoester on prefrontal connectomes were more enduring in the HW (p < 0.05). Elevated BHB level improved cognitive function through decreasing glucose level and increasing causal density, with an estimate of -0.63. Acute ketone monoester supplementation elevated levels of blood BHB and prefrontal connectomes and decreased levels of glucose and cognitive interference, regardless of weight status. Elevated blood BHB enhanced cognitive function through multi-tiered neurometabolic pathways. Clinical trial registration: ClinicalTrials.gov (ID: NCT06368297).

Alterations in regional homogeneity in schizophrenia patients comorbid with metabolic syndrome treated with risperidone or clozapine

The neuroimaging mechanisms that arise in patients with schizophrenia and comorbid metabolic syndrome (MetS) remain poorly understood. This study was devised to examine potential alterations in regional homogeneity (ReHo) that arise in schizophrenia patients with comorbid MetS undergoing risperidone or clozapine treatment. In total, 43 schizophrenia patients undergoing risperidone or clozapine treatment were enrolled in this study, of whom 20 had comorbid MetS (SZ-MetS) while 23 did not (SZ-nMetS). In addition, 28 sex- and age-matched healthy controls (HCs) were analyzed. Analyses of covariance (ANCOVA) were used to compare ReHo in this study, utilizing age, sex, and years of education as covariates, with subsequent post hoc testing. Correlations between brain regions showing differences between groups of patients with schizophrenia and MetS-related indicators were also assessed. Relative to HCs, patients in both the SZ-MetS and SZ-nMetS groups exhibited reductions in ReHo in the right postcentral gyrus, left superior parietal gyrus, and left middle occipital gyrus. A decrease in ReHo was also evident in the left calcarine fissure and surrounding cortex and the right angular gyrus of patients in the SZ-MetS group, while the SZ-nMetS group exhibited reductions in ReHo in the left superior occipital gyrus and the right precuneus, together with an increase in ReHo in the right inferior orbitofrontal gyrus. Compared to the SZ-nMetS group, the SZ-MetS group exhibited a reduction in ReHo in the right inferior orbitofrontal gyrus. The ReHo of the right inferior orbitofrontal gyrus was significantly negatively correlated with BMI, waist circumference, and hip circumference in the SZ-MetS and SZ-nMetS groups. A reduction in ReHo in the right inferior orbitofrontal gyrus may thus be related to MetS in schizophrenia patients undergoing treatment. The findings may provide an imaging basis for brain alterations in patients with schizophrenia combined with MetS and provide a new insight into the neuroimaging mechanisms associated with MetS in patients with schizophrenia.

A Narrative Review on the Neurocognitive Profiles in Eating Disorders and Higher Weight Individuals: Insights for Targeted Interventions

Background/Objectives: Recent research has increasingly explored the cognitive processes underlying eating disorders (EDs), including anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), other specified feeding or eating disorders (OSFEDs), and individuals with higher weight (HW). This critical narrative review focuses on neurocognitive findings derived from mainly experimental tasks to provide a detailed understanding of cognitive functioning across these groups. Where experimental data are lacking, we draw on self-report measures and neuroimaging findings to offer supplementary insights. Method: A search of major databases that prioritized meta-analyses and recent publications (last 10 years) was conducted. Using comprehensive search terms related to EDs, HW, and neurocognition, eligible studies focused on human neurocognitive outcomes (e.g., cognitive flexibility, attentional bias, etc.) published in English were selected. Results: We found that some neurocognitive characteristics, such as cognitive rigidity, impulsivity, emotion processing difficulties, and dysregulated reward processing, appear transdiagnostic, spanning multiple ED subtypes and HW populations. We also revealed neurocognitive features specific to ED subtypes and HW. For instance, individuals with AN demonstrate an enhanced focus on detail, and BN and BED are characterized by a pronounced attentional bias toward food-related stimuli. In individuals with HW, cognitive processes underpin behaviours associated with overeating and weight gain. Conclusions: These findings highlight the critical importance of understanding both the unique and shared neurocognitive patterns across ED subtypes and HW populations. By identifying transdiagnostic factors, such as cognitive rigidity and reward processing, alongside ED subtype/HW-specific vulnerabilities, researchers and clinicians can develop more nuanced, evidence-based interventions that address the core mechanisms driving disordered eating behaviours.

The Impact of Different Types of Exercise on Executive Functions in Overweight/Obese Individuals: A Systematic Review and Network Meta-Analysis

To compare the effects of different exercise training on executive function (EF) in obese or overweight individuals. PubMed, Web of Science, SPORTDiscus, MEDLINE, and CINAHL. The included articles, in English, should have been published from January 2000 to February 2024. All included studies were randomized controlled trials (RCTs) of exercise intervention in overweight or obese populations. The primary outcomes are EFs, which encompass core functions (e.g., inhibitory control, working memory (WM), and cognitive flexibility (CF)) and higher-level functions (e.g., responding, planning, and problem-solving). Therefore, the primary outcomes should include at least one of the above indicators. Additionally, given the focus of many exercise intervention studies on academic performance (AP) in obese adolescents, a secondary outcome includes AP. This meta-analysis synthesizes findings from 20 RCTs published between 2010 and 2023, encompassing a total of 1183 overweight or obese participants. Interventions were categorized into seven types: control training (CT), aerobic exercise (AE), resistance training (RT), coordinated physical activity (CPA), prolonged time of exercise (PTE), high-intensity interval training (HIIT), and AE combined with RT (mix mode, MIX). The surface under the cumulative ranking curve (SUCRA) results demonstrated the preferable effects of various interventions on EF improvement. SUCRA values indicate that CPA performs best in improving the accuracy and reaction speed of CF, as well as the reaction speed of inhibitory control in children and adolescents. AE shows significant effects in enhancing AP in this population. Additionally, PTE excels in improving CF and inhibitory control in middle-aged and older adults. Through subgroup analysis based on age and intervention duration, we found AE exhibited a significant effect on interventions for the 0-17 age group (SMD = 0.84, 95%CI = 0.31~1.38, p = 0.002) and interventions lasting 8-16 weeks showed significant improvement in EFs (SMD = 0.53, 95%CI = 0.00~1.05, p = 0.048). There was also a significant difference between CPA intervention and CT (SMD = 1.12, 95%CI = 0.45~1.80, p = 0.001) in children and adolescents. Additionally, PTE showed significant effects for middle-aged adults aged 17-59 (SMD = 0.93, 95%CI = 0.11~1.96, p < 0.027). Conclusions: This NMA found that CPA and AE have significant benefits for CF, inhibitory control, and AP in children and adolescents. Furthermore, PTE improves EFs in adults and older adults. Combining the findings of this study with previous related research, we recommend that OW/OB begin by interrupting prolonged sedentary behavior and increasing fragmented physical activity, gradually incorporating AE, RT, and CPA (such as jump rope).

Exploring the longitudinal association between stress and unhealthy eating behaviors: The role of physical activity, BMI, and loneliness

Previous cross-sectional research indicates a link between stress and unhealthy eating, but the longitudinal association remains unknown. This study examined the longitudinal association between perceived stress over a longer time period and unhealthy eating (i.e., sweet and savory snack intake, uncontrolled eating) in a student population. Moreover, we examined whether physical activity buffers such association, and examined whether this buffering effect is stronger for individuals with higher Body Mass Index (BMI) or greater loneliness. Two timepoints of online survey data (Time 1 Oct-Nov 2021, Time 2 May-July 2022) of Dutch university students (n = 1325, 74.7 % female, mean age 22.45 (SD = 2.31)) were used. Results revealed no longitudinal link between stress and snack intake in the total sample, but this association was found in a subgroup of individuals with a higher BMI. Stress at Time 1 was associated with later uncontrolled eating. Physical activity did not moderate the link between stress and unhealthy eating. However, we found a negative longitudinal link between physical activity and uncontrolled eating among individuals with a higher BMI. Our findings suggest that stress does not play an important role in explaining snack intake in university students, but may be associated with uncontrolled eating. Physical activity seems to be linked with a reduction in uncontrolled eating among individuals with a higher BMI specifically. Replication and extension of current findings in a more diverse (e.g., eating disordered) sample would increase insights into the (combined) effects of stress, BMI and physical activity on uncontrolled eating.

The Effect of Physical Activity Interventions on Executive Function in Overweight and Obese Adults: A Systematic Review

Background/objectives: Overweight and obesity are global public health problems associated with chronic disease and mental health. Physical activity (PA) is essential throughout a person's life; an active lifestyle helps people to live healthier lives and improve their functional and mental abilities, such as executive function (EF). This systematic review aimed to analyze the evidence on the effects of PA on EF in overweight and/or obese adults (≥18 years old). Methods: Records from the PubMed, ScienceDirect, and JSTOR databases were searched and, following the PRISMA guidelines, seven studies were included in the present systematic review. Risk of bias was assessed using the National Institute of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Results from the studies included indicate that acute, short-term, and long-term PA interventions are an effective strategy to improve inhibitory control, working memory, and processing speed in overweight and obese adults. Furthermore, evidence indicates that EF can be effective as a measure to predict adherence to PA programs and weight loss. Conclusions: Exercise and physical activity interventions are a promising therapeutic strategy to promote weight loss and improve EF in adults with overweight and obesity. Additionally, EF may be further explored as a predictor of healthy aging due to the choices made throughout life and the long-term benefits that result.

Association Between Metabolic Disorders and Cognitive Domains in Community-Dwelling Older Adults

OBJECTIVES

evaluate the association between Metabolic Syndrome (MetS) and cognitive performance (global and in each domain) in community-dwelling older adults.

METHODS

cross-sectional study with 544 participants (≥60 years). Cognition was assessed using the Cognitive Abilities Screening Instrument - Short (CASI-S), evaluating four domains: memory, orientation, executive function, recall. MetS was identified considering five components: abdominal obesity, diabetes, hypertriglyceridemia, low HDL, and hypertension. Mann-Whitney test and Poisson regression models adjusted for age and education were used to assess the differences in cognition scores.

RESULTS

Hypertensive participants had lower global cognition, and those with hypertriglyceridemia had lower memory scores; obese individuals reached lower executive function and higher recall scores. Diabetes was associated with worse recall in men, and low HDL to lower memory scores; hypertensive women had worse recall. In adjusted models, association between abdominal obesity, executive function and recall (total sample) remained significant (p = .003 and p = .048, respectively).

CONCLUSIONS

Global cognition was not associated to metabolic disorders, but obesity was associated to lower executive function and higher recall.

CLINICAL IMPLICATIONS

Assessing each cognitive domain may be more sensitive in subjects with MetS components, and interaction between components, sex and education also must be considered to establish adequate care strategies for the older adults.

Pupillary dilation response to the auditory food words in adolescents with obesity without binge eating disorder

Childhood obesity is a growing global public health problem. Studies suggest that environmental cues contribute to developing and maintaining obesity. We aimed to evaluate pupillary changes to auditory food words vs. nonfood words and to conduct a dynamic temporal analysis of pupil size changes in adolescents with obesity without binge eating disorder by comparing healthy-weight adolescents. In this study, a total of 63 adolescents aged 12-18 years (n = 32, obesity group (OG); n = 31, control group (CG)) were included. In an auditory paradigm, participants were presented with a series of high and low-calorie food and nonfood words. A binocular remote eye-tracking device was used to measure pupil diameter. Generalized additive mixed models (GAMMs) were used for dynamic temporal analysis of pupillometry data. The results of GAMM analysis indicated that CG had larger pupil dilation than the OG while listening to auditory food words. CG had larger pupil dilation in food words than in nonfood words. However, the OG had a similar pupillary response in food and nonfood words. Pupil dilation response to higher-calorie foods was extended over the later stages of the time period (after 2000 ms) in the OG. In summary, our findings indicated that individuals with obesity had lower pupil dilation to auditory food words compared to normal-weight peers. Adolescents with obesity had prolonged pupillary dilation in higher calories of food words. The individual psychological factors affecting the dynamic changes of pupil responses to food cues in adolescents with obesity should be examined in further studies.

Examining the bidirectional longitudinal associations between body mass index and episodic memory following bariatric surgery

BACKGROUND

The relationship between obesity and episodic memory (i.e., conscious memory for specific events) is hypothesized to be bidirectional. Indeed, studies have shown that metabolic and bariatric surgery (MBS) is associated with episodic memory improvement, and better memory is associated with better postsurgical weight-loss outcomes. However, direct tests of the hypothesized bidirectional association between episodic memory and body mass index (BMI) in MBS are lacking, as few studies have employed repeated, prospective assessments of memory in conjunction with bidirectional modeling techniques.

OBJECTIVES

The present study used latent change score analysis to examine the bidirectional longitudinal associations between episodic memory and BMI in the 2 years following MBS.

SETTING

University hospital; public practice.

METHODS

Episodic memory function and BMI were assessed in adults prior to MBS, and at 1, 6, 12, 18, and 24-months postsurgery.

RESULTS

A total of 124 participants (41% lost at 2-year follow-up) showed, on average, favorable weight-loss and episodic memory outcomes following MBS. Crucially, presurgery episodic memory predicted initial change in BMI at 1-month postsurgery, and postsurgery episodic memory at 1- and 6-months predicted change in BMI at 6- and 12-months postsurgery. No evidence was found for pre- and postsurgery BMI predicting changes in episodic memory.

CONCLUSIONS

Results supported a unidirectional prospective relationship between episodic memory and weight change following MBS, such that better memory pre- and postsurgery predicted improved weight-loss outcomes. These findings highlight the likely importance of episodic memory function for weight change and support the potential benefit of targeting memory processes to improve weight-loss outcomes.

Obesity-induced neuronal senescence: Unraveling the pathophysiological links

Obesity is one of the most prevalent and increasing metabolic disorders and is considered one of the twelve risk factors for dementia. Numerous studies have demonstrated that obesity induces pathophysiological changes leading to cognitive decline; however, the underlying molecular mechanisms are yet to be fully elucidated. Various biochemical processes, including chronic inflammation, oxidative stress, insulin resistance, dysregulation of lipid metabolism, disruption of the blood-brain barrier, and the release of adipokines have been reported to contribute to the accumulation of senescent neurons during obesity. These senescent cells dysregulate neuronal health and function by exhibiting a senescence-associated secretory phenotype, inducing neuronal inflammation, deregulating cellular homeostasis, causing mitochondrial dysfunction, and promoting microglial infiltration. These factors act as major risks for the occurrence of neurodegenerative diseases and cognitive decline. This review aims to focus on how obesity upregulates neuronal senescence and explores both pharmacological and non-pharmacological interventions for preventing cognitive impairments, thus offering new insights into potential therapeutic strategies.

Effects of aerobic exercise on executive function among overweight and obese children: a systematic review and meta-analysis

Objective

Overweight and obesity are serious public health issues worldwide and significantly impair children's executive function (EF). However, there is no consensus regarding the benefits of aerobic exercise, on the EF of overweight and obese children. This study systematically evaluated the intervention effects of aerobic exercise on EF and its subcomponents (inhibitory control, working memory, and cognitive flexibility) in overweight and obese children.

Methods

We searched six databases-PubMed, Web of Science, Cochrane Library, Embase, EBSCOhost, and China National Knowledge Infrastructure-until March 17, 2024 for randomized controlled trials examining the effects of aerobic exercise on the EF of overweight and obese children the Cochrane Risk of Bias Assessment Tool. Following heterogeneity testing, RevMan 5.4 and Stata 17.0 were used for meta-analysis and subgroup analysis of the three indicators. The standardized mean difference (SMD) and 95% confidence intervals (CI) were used as statistical measures for effect analysis with the SMD value as the effect size and a p-value of ≤0.05 indicating statistical significance.

Results

Eighteen studies involving 1,260 participants were included. Aerobic exercise significantly improved overall EF (SMD = -0.50, 95% CI [-0.68, -0.32], p < 0.01) with a moderate to high positive effect on inhibitory control (SMD = -0.52, 95% CI [-0.72, -0.31], p < 0.01) and working memory (SMD = -0.63, 95% CI [-1.06, -0.20], p < 0.01) but not on cognitive flexibility (SMD = -0.32, 95% CI [-0.71, 0.07], p = 0.11). These results suggest that EF in overweight and obese children is influenced by factors such as exercise characteristics and body mass index (BMI). Subgroup analysis revealed a significant moderating effect of exercise type, exercise intensity, session time, and individual BMI on EF.

Conclusion

Aerobic exercise selectively improved EF in overweight and obese children. Subgroup analysis indicated that cognitive engagement in ball game interventions of at least moderate intensity and a single session of 25-40 min are more beneficial for improving EF in overweight and obese children. Extremely obese children (BMI > 25 kg/m2) do not benefit from the intervention, highlighting the need for a specific focus on intervention outcomes in future studies.

Working memory gating in obesity is moderated by striatal dopaminergic gene variants

Everyday life requires an adaptive balance between distraction-resistant maintenance of information and the flexibility to update this information when needed. These opposing mechanisms are proposed to be balanced through a working memory gating mechanism. Prior research indicates that obesity may elevate the risk of working memory deficits, yet the underlying mechanisms remain elusive. Dopaminergic alterations have emerged as a potential mediator. However, current models suggest these alterations should only shift the balance in working memory tasks, not produce overall deficits. The empirical support for this notion is currently lacking, however. To address this gap, we pooled data from three studies (N = 320) where participants performed a working memory gating task. Higher BMI was associated with overall poorer working memory, irrespective of whether there was a need to maintain or update information. However, when participants, in addition to BMI level, were categorized based on certain putative dopamine-signaling characteristics (single-nucleotide polymorphisms [SNPs]; specifically, Taq1A and DARPP-32), distinct working memory gating effects emerged. These SNPs, primarily associated with striatal dopamine transmission, appear to be linked with differences in updating, specifically, among high-BMI individuals. Moreover, blood amino acid ratio, which indicates central dopamine synthesis capacity, combined with BMI shifted the balance between distractor-resistant maintenance and updating. These findings suggest that both dopamine-dependent and dopamine-independent cognitive effects exist in obesity. Understanding these effects is crucial if we aim to modify maladaptive cognitive profiles in individuals with obesity.

Treatment as a moderator and executive function as a mediator of the effect of a mindfulness ecological momentary intervention for generalized anxiety disorder

BACKGROUND

Theory and research indicated that executive functioning (EF) correlated with, preceded, and stemmed from worry in generalized anxiety disorder (GAD). The present secondary analysis (Zainal & Newman, 2023b) thus determined whether EF domains mediated the effect of a 14-day (5 prompts/day) mindfulness ecological momentary intervention (MEMI) against a self-monitoring control (SM) for GAD.

METHOD

Participants (N = 110) diagnosed with GAD completed self-reported (Attentional Control Scale, GAD Questionnaire, Perseverative Cognitions Questionnaire) and performance-based tests (Letter-Number Sequencing, Stroop, Trail Making Test-B, Verbal Fluency) at baseline, post-treatment, and one-month follow-up (1MFU). Causal mediation analyses determined if pre-post changes in EF domains preceded and mediated the effect of MEMI against SM on pre-1MFU changes in GAD severity and trait repetitive negative thinking (RNT).

RESULTS

MEMI was more efficacious than SM in improving pre-post inhibition (β = -2.075, 95% [-3.388, -0.762], p = .002), working memory (β = 0.512, 95% [0.012, 1.011], p = .045), and set-shifting (β = -2.916, 95% [-5.142, -0.691], p = .010) but not verbal fluency and attentional control. Within groups, MEMI but not SM produced improvements in all examined pre-post EF outcomes except attentional control. Only pre-post improvements in inhibition mediated the effect of MEMI against SM on pre-1MFU reductions in GAD severity (β = -0.605, 95% [-1.357, -0.044], p = .030; proportion mediated = 7.1%) and trait RNT (β = -0.024, 95% [-0.054, -0.001], p = .040; proportion mediated = 7.4%). These patterns remained after conducting sensitivity analyses with non-linear mediator-outcome relations.

CONCLUSIONS

Optimizing MEMI for GAD might entail specifically boosting inhibition plausibly by augmenting it with dialectical behavioral therapy, encouraging high-intensity physical exercises, and targeting negative emotional contrast avoidance.

Interplay between preclinical indices of obesity and neural signatures of fluid intelligence in youth

Pediatric obesity rates have quadrupled in the United States, and deficits in higher-order cognition have been linked to obesity, though it remains poorly understood how deviations from normal body mass are related to the neural dynamics serving cognition in youth. Herein, we determine how age- and sex-adjusted measures of body mass index (zBMI) scale with neural activity in brain regions underlying fluid intelligence. Seventy-two youth aged 9-16 years underwent high-density magnetoencephalography while performing an abstract reasoning task. The resulting data were transformed into the time-frequency domain and significant oscillatory responses were imaged using a beamformer. Whole-brain correlations with zBMI were subsequently conducted to quantify relationships between zBMI and neural activity serving abstract reasoning. Our results reveal that participants with higher zBMI exhibit attenuated theta (4-8 Hz) responses in both the left dorsolateral prefrontal cortex and left temporoparietal junction, and that weaker temporoparietal responses scale with slower reaction times. These findings suggest that higher zBMI values are associated with weaker theta oscillations in key brain regions and altered performance during an abstract reasoning task. Thus, future investigations should evaluate neurobehavioral function during abstract reasoning in youth with more severe obesity to identify the potential impact.

Improving adult eating behaviours by manipulating time perspective: a systematic review and meta-analysis

There is a growing body of research on improving health behaviours through future thinking but that in improving eating behaviour remains unclear. Hence, we conducted a systematic review and meta-analysis on the effectiveness of time perspective manipulation in improving adult eating behaviours. Articles published from inception through 17 March 2022 were retrieved from eight databases (CINAHL, Embase, ProQuest, PsycINFO, PubMed, Scopus, The Cochrane library, and Web of Science). Meta-analysis was conducted using random effects models with effect sizes reported in Hedges' g. Sixteen experimental studies were included, representing 1,914 participants with mean ages ranging from 20.5 to 44.1 years old and mean baseline BMI of 22.0 kg/m2 to 37.2 kg/m2. The interventions included were episodic future thinking (EFT; n = 12), message framing (n = 2), and varying inter-meal intervals (IMI; n = 2) in improving food choices, food intake and portion size. Two studies reported significant interventional effectiveness for domain-specific EFT while all studies on message framing and IMI reported significant interventional effectiveness. Message framing seemed to be more effective when both temporal distance and valence frames were manipulated. However, the pooled effect sizes of all the interventions did not result in a significant interventional effect (n = 5; g = -0.49; 95% confidence interval (CI) = -1.44, 0.47; p = 0.23; I2=87.2%). More rigorous research is needed to ascertain the effectiveness of manipulating time perspective in improving eating behaviours before such interventions are more widely used.

Predictors of parent self-monitoring patterns in a family-based behavioral weight loss treatment program

OBJECTIVE

Self-monitoring dietary intake is a critical component of family-based intensive health behavior and lifestyle treatment for pediatric obesity, but adherence rates are often low. This study identifies predictors of parent self-monitoring rates during treatment.

METHODS

A secondary analysis of parent self-monitoring data from a randomized controlled trial involving 150 parent-child dyads. Patterns of self-monitoring were identified using a latent class mixed model approach. Logistic regression analyses evaluated predictors of self-monitoring patterns.

RESULTS

Latent class models identified two trajectory groups: a high consistent self-monitoring group and a low-decreasing self-monitoring group. When compared to parents in the low group, parents in the high group lost more weight throughout treatment. Children in the high group had a similar trajectory for weight loss; however, the groups were not statistically different. Higher levels of family chaos and poorer family problem-solving skills were associated with higher odds of being in the low group.

CONCLUSION

This study identified two patterns of rates of parent self-monitoring, which were associated with parent weight loss and were differentiated by family chaos and poor problem-solving. These findings suggest that families with high levels of chaos and poor problem-solving could benefit from early intervention to improve outcomes in pediatric obesity treatment programs.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT01197443.

Additive effects of depression and obesity on neural correlates of inhibitory control

BACKGROUND

Depression and obesity are associated with impaired inhibitory control. Behavioral evidence indicates an exacerbating additive effect when both conditions co-occur. However, the underlying neural mechanisms remain unclear. Moreover, systemic inflammation affects neurocognitive performance in both individuals with depression and obesity. Here, we investigate additive effects of depression and obesity on neural correlates of inhibitory control, and examine inflammation as a connecting pathway.

METHODS

We assessed inhibitory control processing in 64 individuals with obesity and varying degrees of depressed mood by probing neural activation and connectivity during an fMRI Stroop task. Additionally, we explored associations of altered neural responses with individual differences in systemic inflammation. Data were collected as part of the BARICO (Bariatric surgery Rijnstate and Radboudumc neuroimaging and Cognition in Obesity) study.

RESULTS

Concurrent depression and obesity were linked to increased functional connectivity between the supplementary motor area and precuneus and between the inferior occipital and inferior parietal gyrus. Exploratory analysis revealed that circulating inflammation markers, including plasma leptin, IL-6, IL-8, and CCL-3 correlated with the additive effect of depression and obesity on altered functional connectivity.

LIMITATIONS

The observational design limits causal inferences. Future research employing longitudinal or intervention designs is required to validate these findings and elucidate causal pathways.

CONCLUSION

These findings suggest increased neural crosstalk underlying impaired inhibitory control in individuals with concurrent obesity and depressed mood. Our results support a model of an additive detrimental effect of concurrent depression and obesity on neurocognitive functioning, with a possible role of inflammation.

Unveiling the neural mechanisms of acute aerobic exercise on inhibitory control among young adults with obesity: Insights from an ERP study

Obesity has become a prominent public health concern worldwide and is associated with adverse cognitive function. Exercise, particularly aerobic exercise, is known to benefit for weight loss and cognitive function. However, whether acute aerobic exercise could yield benefits to obese individuals and the precise brain mechanisms of action remain poorly understood. The study aimed to investigate whether acute aerobic exercise could improve inhibitory control among obese individuals and what neuroelectric mechanisms are implicated. A 3 (session: control, low-intensity exercise, moderate-intensity exercise) × 2 (congruency: congruent, incongruent) within-subject design was conducted. 18 obese young male adults underwent three sessions of 30-min interventions in a counterbalanced order seperated by five days: moderate-intensity aerobic exercise (MIE), low-intensity aerobic exercise (LIE) and a control session (a sedentary period of seated rest). The Flanker task and EEG recordings (N2 and P3 amplitude) were investigated following exercise and the control treatment. Results showed that the N2 amplitude following MIE was larger than the control session, whereas a larger N2 and reduced congruent P3 amplitude was observed following MIE than LIE. However, no main effect of the session was found for reaction time and accuracy, but a significant main effect of congruency was observed. These findings suggest acute moderate-intensity aerobic exercise may modulate brain activity through enhanced recruitment of attentional resources for cognitive control and conflict monitoring in adults with obesity.

[Cognitive impairment in patients with obesity and impaired carbohydrate metabolism (dysglycemia)]

Obesity is a chronic disease, heterogeneous in etiology and clinical manifestations, progressing with a natural course, characterized by excessive deposition of fat mass in the body. This pathological condition has taken on the scale of a global epidemic in recent years, which continues to progress steadily, currently affecting more than 2 billion people worldwide. Due to its heterogeneity, obesity has a negative impact on the work of almost all organs and systems of the body, contributing to the emergence of new concomitant diseases and pathological conditions that significantly worsen the quality of life of these patients. Thus, a close relationship between type 2 diabetes mellitus and cognitive impairment has long been known, as well as with a number of other somatic diseases: coronary heart disease, atherosclerosis, non-alcoholic fatty liver disease, dyslipidemia, malignant neoplasms and other associated pathological conditions against the background of overweight and obesity.Currently, the problem of the relationship of cognitive impairment in patients with overweight or changes in the glycemic profile is very relevant, due to the high prevalence and insufficient study of this issue.

Family screening for neurodevelopmental problems and its associations with child cognitive function enable tailored treatment for childhood obesity

AIM

To identify neurodevelopmental disorders in children with obesity, and investigate associations to cognitive functions as well as parents' self-reported neurodevelopmental problems.

METHODS

Eighty children were included at two outpatient obesity clinics in Sweden 2018-2019. Of these, 50 children without previously diagnosed neurodevelopmental disorders were screened, and so were their parents. Children who screened positive for neurodevelopmental problems were referred to a specialised psychiatry unit for further diagnosis. Test results of cognitive functioning were compared with the norm and between study groups by neurodevelopmental diagnoses.

RESULTS

Of the screened families, 17/50 children were diagnosed by the psychiatric unit with attention deficit-hyperactivity disorder (ADHD) and 15/82 parents screened positive for neurodevelopmental problems. Having a mother who screened positive for neurodevelopmental problems was associated with child ADHD (p < 0.05). The children's full-scale intelligence quotient (92.86 ± 12.01, p < 0.001) and working memory index (90.62 ± 12.17, p < 0.001) were lower than the norm. Working memory index was lower in children with ADHD compared to without ADHD: 84.76 ± 9.58 versus 94.09 ± 12.29 (p ≤ 0.01). Executive constraints were associated with verbal deviances.

CONCLUSION

Increased awareness is needed about the overlap between neurodevelopmental problems and obesity in obesity clinics.

Association of obesity to reaction time and visual memory in schizophrenia

Background

Both overweight and cognitive deficits are common among people with schizophrenia (SZ) and schizoaffective disorder. The results in earlier studies have been inconsistent on whether overweight is associated with cognitive deficits in psychotic disorders.

Aims

Our aim in this study was to detect possible associations between obesity and cognitive deficits among study participants with SZ and schizoaffective disorder.

Methods

The study sample included 5382 participants with a clinical diagnosis of SZ or schizoaffective disorder selected from the Finnish SUPER study. Obesity was measured both with body-mass index and waist circumference. The cognitive performance was evaluated with two tests from the Cambridge automated neuropsychological test battery: Reaction time was evaluated with the 5-choice serial reaction time task. Visual memory was evaluated with the paired associative learning test. The final analysis included a total sample of 4498 participants applicable for the analysis of the reaction time and 3967 participants for the analysis of the visual memory.

Results

Obesity measured with body-mass index was associated with better performance in reaction time task among both female and male participants. Among male participants, overweight was associated with better performance in the visual memory test. The waist circumference was not associated with cognitive measures.

Conclusions

The results suggest that obesity in people with SZ or schizoaffective disorder might not be associated with cognitive deficits but instead with better cognitive performance. The results were opposite from earlier literature on the general population. More research is required to better understand whether the results might be partly caused by the differences in the etiology of obesity between the general population and people with SZ.

The relationship between cardiorespiratory fitness and inhibitory control following acute stress: An ERP study

Although the relationships among acute stress, cardiorespiratory fitness (CRF), and cognitive function have been examined, whether CRF is related to behavioral and neuroelectric indices of inhibitory control following acute stress remains unknown. The purpose of the current study was to investigate the combined influence of acute stress and CRF on inhibitory control. Participants, aged 20-30 years, were stratified into the Higher-Fit (n = 31) and the Lower-Fit (n = 32) groups, and completed a Stroop task following the modified Maastricht Acute Stress Test (MAST) in the stress condition and the sham-MAST in the non-stress condition, during which electroencephalography was recorded. Behavioral (i.e., response time and accuracy) and neuroelectric (N2 and P3b components of the event-related potential) outcomes of inhibitory control were obtained. While the Higher-Fit group demonstrated shorter response times and higher accuracy than the Lower-Fit group following both the MAST and the sham-MAST, they also exhibited selective benefits of acute stress on inhibitory control performance (i.e., decreased response times and diminished interference scores). CRF-dependent alterations in neuroelectric indices were also observed, with the Higher-Fit group displaying smaller N2 and greater P3b amplitudes than the Lower-Fit group following the sham-MAST, and increased N2 and attenuated P3b amplitudes following the MAST. Collectively, these findings not only confirm the positive relationship between CRF and inhibitory control but also provide novel insights into the potential influence of CRF on inhibitory control and associated neuroelectric activity following acute stress.

Allostatic load, adverse childhood experiences, executive functions, and BMI status in adolescents and young adults

OBJECTIVES

Chronic stress induces preclinical changes in the metabolic, cardiovascular, and immune systems. This phenomenon, known as allostatic load (AL), can impair executive functions (EF), which may be even more affected in individuals with excess weight due to their characteristic inflammatory state and cardiometabolic changes. Adverse childhood experiences (ACEs) contribute to AL and may influence executive functioning presumably via alterations within the hypothalamic-pituitary axis, including epigenetic modifications. We assess the relationship between AL and EF in youth with and without excess weight, and the effect ACEs on executive functioning.

METHODS

One hundred eighty-two adolescents and young adults (85 with normal weight and 97 with overweight/obesity; 10-21 years) were recruited. The estimated AL index included the following: systolic and diastolic blood pressure, glycated hemoglobin, high- and low-density lipoprotein cholesterol, triglycerides, high-sensitivity C-reactive protein, fibrinogen, and cortisol. ACEs were measured using the Juvenile Victimization Questionnaire. The neuropsychological evaluation included the assessment of inhibition, working memory, and cognitive flexibility processes.

RESULTS

AL was not significantly associated with executive functioning, and this relationship did not depend on body-weight status. ACEs, available for 57 of 182 participants, were significantly associated with poorer executive functioning.

CONCLUSIONS

Our study shows that AL is not associated with executive functioning in adolescents and young adults. Since the current sample was young, we hypothesize that a longer exposure to AL might be required for its negative effects to surface. Nevertheless, exposure to early adversity seems to be associated with poorer executive functioning in youth.

Functional alterations in overweight/obesity: focusing on the reward and executive control network

Overweight (OW) and obesity (OB) have become prevalent issues in the global public health arena. Serving as a prominent risk factor for various chronic diseases, overweight/obesity not only poses serious threats to people's physical and mental health but also imposes significant medical and economic burdens on society as a whole. In recent years, there has been a growing focus on basic scientific research dedicated to seeking the neural evidence underlying overweight/obesity, aiming to elucidate its causes and effects by revealing functional alterations in brain networks. Among them, dysfunction in the reward network (RN) and executive control network (ECN) during both resting state and task conditions is considered pivotal in neuroscience research on overweight/obesity. Their aberrations contribute to explaining why persons with overweight/obesity exhibit heightened sensitivity to food rewards and eating disinhibition. This review centers on the reward and executive control network by analyzing and organizing the resting-state and task-based fMRI studies of functional brain network alterations in overweight/obesity. Building upon this foundation, the authors further summarize a reward-inhibition dual-system model, with a view to establishing a theoretical framework for future exploration in this field.

Beyond Distracted Eating: Cognitive Distraction Downregulates Odor Pleasantness and Interacts with Weight Status

Considering the widespread issue of distracted eating, our study investigates how cognitive distraction influences the sensory perception of food-related odors among individuals with varying weight statuses. We conducted an exploratory, randomized, and cross-sectional experimental study, using the Tetris game to simulate real-life cognitive distraction, incorporating two distraction levels (low and high) and presenting five distinct odors. A total of 59 participants, categorized into a lean (n = 30) and overweight/obese group (n = 29) based on their body mass index (BMI), received odor stimuli while playing Tetris at low and high difficulty, corresponding to low and high distraction levels, respectively. Participants subsequently rated odor intensity and pleasantness under the two cognitive distraction conditions. Respiratory movements were monitored to ensure accurate olfactory stimulation. Our findings revealed no significant difference in odor intensity ratings across distraction levels (p = 0.903). However, there was a significant reduction in odor pleasantness under high cognitive distraction (p = 0.007), more pronounced in lean participants compared to those with an overweight status (p = 0.035). Additionally, an interaction between gender and cognitive distraction effects was observed in odor pleasantness perception. The differential effects of distraction across weight-status groups and genders are discussed in the context of hedonic motivation and compensatory mechanisms. This study sheds light onto the sensory mechanisms underlying distracted eating and could inform more personalized strategies for promoting healthier eating habits in a world dominated by distractions.

Neural activity and connectivity are related to food preference changes induced by food go/no-go training

Simply withholding a response while viewing an appetizing food, over the course of many presentations (i.e., during food go/no-go training) can modify individuals' food preferences-which could, in turn, promote healthier eating behaviors. However, the neural mechanisms underlying this food go/no-go training-induced change in food preferences are still relatively unclear. We addressed this issue in the present functional magnetic resonance imaging (fMRI) study. To this end, we administered a novel passive viewing task before and after food go/no-go training to 91 participants in the scanner. Participants' food preferences were measured with a binary food choice task. At the behavioral level, we found the expected training effect on food preferences: Participants preferred go over no-go foods following training. At the neural level, we found that changes in food preferences were associated with training-related go vs. no-go differences in activity and functional connectivity, such as less activity in the anterior cingulate cortex and superior frontal gyrus but greater functional connectivity between the superior frontal gyrus and middle occipital gyrus. Critically, Dynamic causal modeling showed that this preference change effect was largely driven by top-down influence from the superior frontal gyrus to the middle occipital gyrus. Together, these findings suggest a neural mechanism of the food go/no-go training effect-namely, that the food-viewing-related interplay between prefrontal regions and visual regions might be related to the food preference change following food go/no-go training.