Appetite

BackgroundDistracted eating is prevalent in modern environments. While behavioral research consistently shows that distraction attenuates taste perception and increases food intake, the underlying neural mechanisms appear to be more complex. ObjectiveThis functional magnetic resonance imaging (fMRI) study investigated whether naturalistic distraction modulates gustatory processing via sensory suppression or reallocation of neural resources, as observed in more controlled cognitive load paradigms. MethodsThirty-eight healthy participants received sweet and umami taste stimuli of low and high concentration during fMRI scanning. Attentional state was manipulated using short food-related (low-distraction) versus film-related (high-distraction) video clips. After each video, participants rated perceived intensity and pleasantness. Group-level analyses included covariates for sex, body mass index (BMI), and hunger level. ResultsHigh distraction attenuated perceived intensity (p < 0.001, d = -0.28) and pleasantness (p < 0.01, d = -0.21), independent of taste category or concentration. No significant attenuation by distraction was observed in core gustatory regions (insula, orbitofrontal cortex). Instead, distraction increased activation in occipital, thalamic, and cerebellar regions, indicating a redistribution of processing resources toward visual and attentional systems. ConclusionDistraction reduced taste salience without lowering gustatory cortex activity, supporting resource-competition models rather than active sensory suppression. These results reinforce that the impact of distracted eating is behaviorally robust yet neurally subtle, highlighting the need for personalized stimuli and ecologically valid methods to capture real-world eating behavior. The study demonstrates that video-based paradigms work reliably in fMRI and capture how naturalistic distraction alters taste experience.

Background Emerging evidence highlights the gut-brain axis as a key pathway linking diet and anxiety, yet the key determinants remain unclear. Most studies have focused on single components of diet and rarely integrate long- and short-term intake. Furthermore, prior gut-brain work has focused on microbiome composition, while functional features remain underexplored. In this study, we investigated associations between long- and short-term dietary intake, gut microbiome composition and functions, and anxiety in a subclinical cohort of 46 females (18-24 years) from the United Kingdom. Results Long-term diet quality was assessed using the Healthy Eating Index (HEI-2020) derived from a food frequency questionnaire, stratifying participants into lower and higher diet quality clusters. Short-term dietary intake was assessed via 24-hour recalls. Shotgun metagenomics of stool samples was used to assess differences in alpha and beta diversity indices, species abundances, and bacterial pathways putatively metabolizing gut-brain-axis-relevant molecules. Anxiety was measured using the State-Trait Anxiety Inventory (state subscale STAI-s). Regression models identified diet quality (HEI cluster) as the primary dietary feature of anxiety variation. The presence of Ruminococcus gnavus and Flavonifractor plautii and the abundances of Bilophila wadsworthia and Bacteroides thetaiotaomicron were positively associated with anxiety. The presence of Feacalibacterium prausnitzii and greater abundances of butyrate, propionate, and GABA synthesis pathways were inversely associated with anxiety. Non-linear models revealed a U-shaped relationship between inositol synthesis and STAI-s. Finally, we found that habitual diet quality may modulate anxiety-related responses to short-term dietary variation. Conclusions These findings reveal widespread links between long-term diet quality, microbiota composition and function, and anxiety symptoms. These results point towards several promising targets for prebiotic, probiotic, postbiotic, and dietary interventions aimed at reducing anxiety.

Obesity is a growing public health concern with more than 40% of adults meeting criteria for obesity in the United States. Although many treatments seek to lower individuals weight, few treatments have focused on cognitive strategies to change the way individuals think about food, therefore, decreasing consumption of non-nutrient-dense foods. Cognitive reappraisal is one strategy that involves changing the way one thinks about a situation and can be used to downregulate responses to those stimuli. Leveraging this intuitive, cost-effective strategy to decrease ones desire to eat unhealthy food and therefore, decrease overeating, could improve physical and mental health. The present study identified brain regions that are differentially activated when using cognitive reappraisal to downregulate responses to food (FR) versus when using the same strategy to downregulate negative emotions (ER). We collected functional magnetic resonance imaging (fMRI) data in 63 undergraduate students while participants completed both tasks. There was increased reappraisal-related activation in widespread regions across both tasks, including in expected subcortical (i.e., striatum) and cortical areas (i.e., visual, frontoparietal). We also found domain-specific activity, with greater insula activation in the FR than the ER task and greater hippocampal activation in the ER than the FR task. These results reveal domain-general and domain-specific effects of cognitive reappraisal in FR and ER tasks that inform future work examining eating behavior. Taken together, a better explication of the overlapping and discrete processes of food regulation, as it compares to other applications of this regulatory strategy can inform new intervention targets.

BackgroundObesogenic diets (ODs) are known to trigger metabolic and inflammatory disturbances. However, the effects of short-term OD withdrawal on systemic and neuroinflammatory parameters remain unclear. ObjectivesThis study investigated the short-term effects of OD withdrawal on metabolic, inflammatory, and anxiety-like behaviours in young male Wistar rats. MethodsThree-week-old male Wistar rats were fed either a control (Ct, n=5) or high-sugar/high-fat (HSHF) diet for 14 days. Animals in the HSHF group were further divided into no-withdrawal (NWt, n=5) and withdrawal (Wt, n=5) groups, where Wt received a control diet for 48 hours. Food intake, body mass, adiposity, serum metabolic parameters, hepatic energy stores, inflammatory markers (serum, liver, hypothalamus, hippocampus, mesenteric fat), and oxidative stress markers in the hippocampus were measured. Anxiety-like behaviour was assessed using the elevated plus maze. ResultsOD intake significantly increased caloric intake, visceral adiposity, hepatic glycogen, and TAG levels. The 48-hour withdrawal reduced TAG, induced hyperinsulinemia and hypoglycaemia, and heightened inflammation in mesenteric fat, serum, and the hippocampus. Oxidative stress markers (SOD and MDA) increased in the hippocampus, correlating with elevated serum corticosterone and heightened anxiety-like behaviour in the Wt group compared to the other groups. ConclusionShort-term withdrawal after only two weeks of OD intake exacerbates systemic and neuroinflammation, hippocampal oxidative stress, and anxiety-like behaviours, indicating rapid negative responses to dietary transition. These findings highlight the metabolic and behavioural challenges associated with short-term OD withdrawal and highlight the need for adjunct interventions to mitigate its adverse effects.

Genetic variation contributes to individual differences in food liking and dietary behaviour. Genome-wide association studies (GWAS) have identified genetic variants associated with these traits, but most evidence comes from middle-aged and older populations. Young adulthood is a key life stage during which long-term dietary habits develop, yet the genetic basis of food liking during this period remains largely unexplored. We conducted GWAS of 97 food liking traits and two derived principal components (PCs) in 2,784 young adults (age 25) from the Avon Longitudinal Study of Parents and Children. The PCs captured broader food preference patterns reflecting preferences for diverse plant-based and seafood foods (PC1) and meat-based foods (PC2). GWAS identified 32 genome-wide significant associations across 24 traits. Cross-trait analyses indicated that several variants influenced liking across groups of related foods. For example, the lentil-associated variant rs76659918 showed associations with multiple foods, including honey, plain yogurt, chilli peppers, aubergines, avocado, and black olives, as well as PC1, whereas variants associated with bacon, burgers, and steak were linked to multiple meat-based foods and PC2. Exploratory analyses showed that TAS2R38 bitter-sensitive alleles were associated with lower liking for Brussels sprouts, with limited evidence for associations with other traits. Comparison with GWAS of food liking in the UK Biobank cohort (age 37-73) showed limited replication, with robust evidence only for the grapefruit-associated locus. This study identifies genetic variants associated with food liking in young adulthood and suggests that genetic influences operate at both the level of individual foods and broader food preference patterns.

BackgroundFood-related gastrointestinal (GI) symptoms are highly prevalent in patients with IBS. Although dietary components may trigger symptoms through luminal mechanisms, cognitive expectations may also shape symptom perception within the gut-brain axis. No validated instrument currently exists to measure food-related symptom expectations. Hence, we developed and validated the Food Expectation Questionnaire (FEX-Q). MethodsThe FEX-Q was developed using a stepwise process including focus group interviews and face-to-face validation to ensure content validity. The finalized digital questionnaire presents 44 food images with six items rated on a visual analogue scale (VAS; 0-100), including the core item assessing food-related symptom expectation ("How severe GI symptoms do you expect after eating this food?"). Additional domains assess taste preference, willingness to eat, perceived healthiness, and perceived fat and carbohydrate content. The finalized FEX-Q was administered in a nationwide online validation survey of adults with IBS and non-IBS controls in Sweden. Participants also completed validated questionnaires including GI symptom severity (combined GSRS), psychological distress (HADS), food-related quality of life (FR-QOL), and a screening tool for food avoidance (NIAS). ResultsTwenty adults with IBS and non-IBS controls participated in the face-to-face validation, resulting in a final version of the FEX-Q comprising 44 food images, which were properly identified and provided a range of macronutrient distributions and trigger foods. In the nationwide online study including 134 patients with IBS and 126 non-IBS controls, the FEX-Q demonstrated strong known-groups validity (mean symptom expectation 18.4 in controls vs 50.1 in IBS), strong construct validity (perceived vs actual fat content r=0.78, p<0.001 and carbohydrate content r=0.59, p<0.001), significant convergent validity with GI symptom severity and food-related quality of life, and high internal consistency (split-half reliability Spearman-Brown corrected r=0.88). ConclusionThe FEX-Q can capture individual food-related symptom expectations to distinct food images. This reliable measurement can be useful to reveal the mechanism of food-related symptom expectations and provide clinically relevant insights for personalized dietary management

Dietary choice plays a critical role in metabolic and neurological health, yet the biological factors that shape macronutrient preference remain poorly understood. Evidence from both humans and rodents suggests potential sex differences in the attractiveness of specific nutrients, though findings have been inconsistent and often rely on self-report or diets with mixed macronutrient composition. The present study examined sex differences in macronutrient preference and food-directed behavior in mice using a controlled three-food choice paradigm. Adult male (n = 12) and female (n = 11) C57BL/6J mice were given simultaneous access to foods consisting of fat, sucrose, or a fat-carbohydrate combination across 14 days. Intake, latency to approach, and time spent near each food source were quantified, and estrous cycle stage was monitored in females. Female mice consumed significantly more food than males overall, driven by a selective increase in fat intake. Behavioral measures paralleled these results, with females spending more time in proximity to fat-associated food zones. In contrast, males preferentially consumed the fat-carbohydrate combination and showed weaker nutrient-specific engagement. Estrous cycle stage modestly influenced feeding behavior, with estrus associated with increased overall intake and greater consumption of combination diets, reflecting elevated carbohydrate intake. These findings demonstrate robust sex differences in macronutrient preference and suggest that hormonal state may selectively modulate nutrient-specific feeding behavior.

Dietary patterns worldwide have shifted toward increased consumption of ultraprocessed foods (UPFs), which has been linked to higher disease burden. One mechanism proposed to impact both their consumption and contribution to metabolic disease is altered post-ingestive metabolic response in comparison to nutritionally similar foods. Here, we recruited 57 healthy-weight 18-45-year-old adults to examine the effects of food processing on postprandial metabolism and brain response. Despite nutritional matching, UPF meals evoked a greater insulinemic and energetic response with attenuated carbohydrate oxidation relative to non-UPF meals. Next, between-condition differences in peak carbohydrate oxidation were associated with mesolimbic and superior temporal gyrus activation in response to food cues. Finally, although food value did not differ between conditions, brain responses correlated with food valuation were positive for non-UPF but negative for UPF in visual cortex and striatum. These findings demonstrate that food processing influences post-ingestive metabolism in a way that could help explain long term health effects and differences in food reward through mechanisms beyond calories and macronutrient composition alone.

Despite growing availability of plant-based meat, limited data exist on how these products perform relative to animal-based options in real-world consumption settings. This study compares consumer sensory perceptions of two plant-based meatballs (soy, soy-wheat) and two animal-based meatballs (beef, beef-mushroom) among university dining hall patrons (n = 128), complemented by instrumental Texture Profile Analysis. Animal-based meatballs received significantly higher ratings for moistness, meatiness, fattiness, and tastiness (all p < 0.001), with the meatiness gap being the largest ({Delta} = 1.40 on a 5-point scale). Texture analysis found that animal-based samples were significantly harder, more cohesive, and chewier than plant-based samples. In contrast, consumers perceived no difference in chewiness or hardness between categories, revealing a disconnect between instrumental and sensory measures. Just-About-Right penalty analysis identified insufficient savoriness as a universal improvement target across all products, including beef. Flavor and texture were the dominant drivers of dining choice, while sustainability and animal welfare ranked lowest in importance. These findings indicate that achieving sensory parity--particularly in moistness, meatiness, and savoriness--rather than emphasizing sustainability messaging, may be critical for increasing acceptance of plant-based meat in institutional food service. Data and code are available at https://github.com/LivingMatterLab/AI4Food

IntroductionMechanistic research has shown that prior obesity induces durable transcriptomic and epigenetic reprogramming in adipose tissue that persists after weight loss and predisposes individuals to weight regain. This phenomenon, termed obesogenic memory (OM), is currently conceptualized primarily as a molecular process. We propose extending OM beyond adipose tissue biology to include interacting biological and sociocultural processes through which past exposures shape present physiological regulation and health-related behavior. MethodsIn-depth qualitative interviews were conducted with individuals living with obesity (n=31) and with healthcare professionals (n=18). The data were analyzed abductively to examine participants lived experiences of obesogenesis. ResultsWe developed a three-phase model of OM comprising memorizing, remembering, and rescribing. The memorizing phase describes the initial acquisition and encoding of biological and sociocultural obesogenic influences. The remembering phase captures the persistence of these influences, contributing to long-term obesity maintenance. The rescribing phase refers to processes through which obesogenic influences may be attenuated or reversed, creating conditions for sustainable health behavior change. ConclusionExtending OM to include sociocultural dimensions provides a more comprehensive understanding of obesity persistence. This integrative framework identifies multilevel targets for obesity prevention and treatment that acknowledge past exposures while supporting resilience and long-term weight management.

Introduction High consumption of ultra-processed foods (UPF) is associated with adverse health outcomes and weight gain. Despite increasing calls for behavioural strategies to reduce UPF intake, no theory-informed intervention targeting UPF reduction has been evaluated in UK adults in alignment with national dietary guidance. We assessed the feasibility, acceptability, and preliminary behavioural and clinical outcomes of a multi-component intervention designed to reduce UPF consumption (and increase physical activity (PA)/minimally processed food (MPF) intake). Methods In this exploratory single-arm pre-post study, adults (N=45) living with overweight or obesity and habitual UPF intake [&ge;]50% of total energy were offered a 6-month behavioural intervention following a controlled feeding phase (UPDATE trial, stage 1). The intervention was developed using the Behaviour Change Wheel and Capability, Opportunity, Motivation-Behaviour (COM-B) model and included one-to-one sessions with a behavioural scientist, tailored print and digital materials, peer-support meetings, and a moderated group chat. Feasibility outcomes included uptake, retention, and intervention fidelity. Secondary outcomes included COM-B constructs, dietary intake, PA, clinical and self-reported outcomes, and qualitative feedback. Results Uptake was 91% (41/45). Retention at 6 months was 68% (28/41), with 83% (34/41) providing follow-up data (intention-to-treat). Median attendance at one-to-one sessions was 86% (interquartile range (IQR): 57-100) with 56% (23/41) attending all sessions (per-protocol). Fidelity to core behaviour change techniques was high. At 6 months, COM-B scores improved for healthy eating (+7%, standard deviation (SD): 8; p<0.001) and physical activity (+5%, SD: 9; p=0.013). UPF intake decreased by 25% of total energy (95% confidence interval (95%CI): -32, -17), with a corresponding increase in minimally processed foods (+23%; 95%CI: 17, 29). Vigorous physical activity increased (+60 min/week, IQR: 0-180), weekday sitting time decreased (-61 min/day, SD: 110), and weight reduced by 3.8 kg (IQR: -8.5-1.0; p=0.001). Findings were similar in per-protocol analyses. Qualitative data indicated perceived improvements in wellbeing and habit formation. Conclusion This theory-informed intervention demonstrated good feasibility and acceptability and was associated with improvements in targeted behavioural mechanisms and health-related outcomes. A randomised controlled pilot trial is warranted to evaluate effectiveness and refine implementation.

There is evidence that appetites for specific nutrients can guide foraging behaviour and aid in dietary regulation through associative learning processes that link stimuli to nutrient-specific outcomes. However, most, if not all, examples of such behaviour can be interpreted as being stimulus-bound habits, i.e., reflexive responses induced by environmental stimuli. The control of identified goal-directed actions by nutrient-specific appetites has not been directly assessed. To address this question, we trained rats to press a lever for a high protein reward (whey protein shake) and another lever for a high carbohydrate reward (polycose solution). They were then tested under extinction conditions in which both levers were available following the extended exposure to meals that were high in protein or carbohydrate. When otherwise food-deprived rats had been selectively satiated on protein immediately prior to test, they pressed more on the lever they learned had produced polycose, whereas they pressed the lever they learned had produced whey protein more if they had instead been satiated on carbohydrate. Crucially, the same pattern emerged whether the satiety manipulation was achieved using the same nutrient sources that rats had earned during training (i.e., whey or polycose) or with foods high in the relevant nutrients, indicating that these behaviours were under goal-directed control and sensitive to nutritional state. These results show that actions can be motivated by the nutritional relevance of the instrumental outcome to specific appetites, a relationship that may guide natural foraging decisions.

Introduction: Eating behaviors are consistently associated with weight-related traits, yet the biological factors contributing to individual differences in these behaviors remain poorly characterized. Plasma proteomics offers an opportunity to investigate the biological processes underlying eating behaviors. Methods: Participants were 730 young adult twins from the FinnTwin12 cohort. Eating behaviors were measured through self-report questionnaires, including the Three-Factor Eating Questionnaire-R18 and four additional items on eating styles. Associations between plasma proteins and eating behaviors were examined using generalized estimating equation models adjusted for age and sex, with additional analyses adjusting for body mass index (BMI). Within-pair analyses were conducted in both monozygotic (MZ) and dizygotic twin pairs to assess whether associations were influenced by genetic or environmental factors. Results: We identified 51 significant protein-eating behavior associations involving 35 unique proteins (FDR <0.05). We observed 19 associations for the item "overeating when feeling down" and 12 for the TFEQ factor of emotional eating. The identified proteins were predominantly enriched in immune system pathways, including the complement cascade and adaptive immune signaling. After further adjustment for BMI, 12 associations persisted, most of which were associated with eating-style items, suggesting that BMI had a substantial influence on protein-eating behavior associations. Within-pair analyses of MZ pairs indicated that several associations persist after accounting for genetic effects. Conclusion: Our study identifies plasma proteins associated with eating behaviors, largely involving immune-related pathways. While some associations attenuated in twin analyses, several persisted, suggesting environmental influences. These results highlight potential biomarker candidates and indicate that modifiable environmental factors may contribute to the proteomic profiles associated with eating behaviors, with possible implications for weight-related traits.

BackgroundAnorexia nervosa (AN) remains difficult to treat, partly due to co-occurring mental health challenges and gastrointestinal symptoms. Emerging research suggests that individuals with AN exhibit gut microbiota dysbiosis and dysregulation in the gut-brain axis (GBA). However, research examining the role of gut microbiota as a potential driver of AN-related pathologies remains limited. The Norwegian Microbiota Study in Anorexia Nervosa (NORMA) will therefore investigate gut microbiota and its interaction with the GBA in AN. MethodsNORMA is a collaboration between the Norwegian University of Life Sciences and seven Norwegian specialized eating disorder inpatient treatment units, consisting of three work packages (WP): a clinical observational trial (WP1), in vitro fermentation experiments (WP2), and animal experiments (WP3). In WP1, 90 patients with AN (age 16-50, BMI<18.5) admitted for treatment and 90 healthy controls (HCs, age 16-50, BMI 18.5-27) will be recruited. Data on mental and physical health, dietary intake, and blood and fecal samples for biomarker and microbiota analyses will be collected at baseline, 6 and 12 weeks after start of treatment for AN patients and once for HCs. Outcomes will be compared between groups, and longitudinal effects of standard treatment examined within the AN group. In WP2, fecal microorganisms from patients and HCs will be grown in vitro to assess influence of prebiotics. In WP3, mice will receive fecal microbiota from AN and HC donors to determine if and how AN-related microbiota affects AN-relevant phenotypes. ConclusionNORMA is pioneering in its integration of clinical, in vitro, and animal studies, providing the most comprehensive gut microbiota study of AN so far. By investigating the role of gut microbiota in AN and effects of standardized treatment on gut microbiota composition, this study aims to inform the development of innovative therapeutic strategies and ultimately improve treatment outcomes and life quality for individuals with AN. Trial registrationNORMA is a registered clinical trial: clinicaltrials.gov as NCT06144905.

Obesity prevalence continues to rise in the United States, with a disproportionate burden falling to West Virginia. To investigate the metabolic effects of region-specific dietary patterns, we developed the West Virginia Obesogenic Diet (WV-OD), a compositionally defined rodent diet based on nutritional analyses of meals consumed by obese individuals in the state. The WV-OD closely mirrors the macronutrient profile of the average American diet while incorporating regional features such as a greater sodium level and significantly less fiber. We compared the metabolic effects of the WV-OD to a matched control diet (WV-CD) and to a widely used high-fat diet (HFD, 60% of calories derived from fat) in male and female C57BL/6J mice. After 19 weeks, WV-OD-fed males exhibited weight gain and adiposity comparable to HFD-fed counterparts, along with glucose intolerance and hepatic triglyceride accumulation confirming the obesogenic and metabolically disruptive properties of the WV-OD. Unlike HFD-fed mice, WV-OD-fed males also displayed elevated circulating cholesterol and cholesterol esters without corresponding increases in hepatic total cholesterol. When compared to the HFD, the WV-OD did not increase uric acid or xanthine oxidoreductase (XOR) content of liver or circulation; however, both males and females on the WV-OD demonstrated trends towards elevated plasma uric acid. Interestingly, while exhibiting a similar caloric intake on either diet, the WV-OD females did not demonstrate significant fat accretion or metabolic dysfunction compared to females subjected to the 60% HFD. In toto, these findings: 1) establish the WV-OD as a regionally-grounded, yet broadly representative tool for modeling diet-induced obesity and metabolic dysfunction, 2) offer a physiologically relevant alternative to extreme-fat dietary models in preclinical research and 3) highlight sex-based differences in response to diet-induced obesity.

The prevalence of obesity is rising worldwide in young people and is associated with poor long-term health outcomes. To counter obesity, weight loss strategies especially involve changes in feeding behaviors and food choice. However, the high level of relapse to unhealthy dietary habits represents an important challenge, suggesting long-term alterations of decision-making and food-seeking processes. Previous studies showed that adolescence is critical for the development of decision-making functions. Thus, it is essential to understand the precise impact of the exposure to obesogenic diets during this life stage on the different processes underlying flexible control of food-seeking actions. To address this, we gave mice access to high-fat diets (HFDs) with different fat contents during adolescence and investigated the long-lasting impact on action control at adulthood after a switch to a healthy diet. We uncovered important sex differences. In both males and females, exposure to HFD with very high-fat content (60%) promote inflexible habitual behavior, which is less flexible to adapt to changes in outcome value or action-outcome relationships. In contrast, exposure to HFD with lower fat content (45%) impaired action control based on the updating of outcome value in males only, while impairing action control based on the updating of action-outcome relationships in females only. These findings highlight how the consumption of obesogenic diets during adolescence has long-lasting, diet- and sex-dependent effects on decision-making processes, promoting habitual responses to food. These changes may support long-term vulnerability for mental and physiological health conditions.

The gut microbiome plays a vital role in metabolism, behavior, and overall health, with diet being a key factor shaping its composition. This study examines the impact of intermittent palatable food (PF) consumption on microbiota structure in male and female rats, focusing on feeding preferences and sex differences. Rats were characterized as high preferring (HP) or low preferring (LP) based on PF intake, and microbial analyses were conducted across different gastrointestinal regions, including the colon, feces, cecum, and cecal contents. However, microbiota composition varied with significant differences in Firmicutes, Bacteroidetes, and Actinobacteria abundances. Sex-based differences were evident particularly in fecal and cecal samples, where Proteobacteria and Actinobacteria populations varied between males and females within the same feeding groups. Our findings support the notion that dietary habits and microbiota composition may form a feedback loop, reinforcing food preferences through gut-brain axis signaling. While alpha diversity remained unchanged, beta diversity analysis indicated subtle, but significant differences in microbial community structures based on sex and feeding behavior. This research provides novel insights into the interplay between diet, gut microbiota, and behavior, while emphasizing the importance of considering sex as a variable in microbiome studies. Understanding these relationships may inform dietary interventions aimed at optimizing microbiota composition to improve metabolic and mental health outcomes linked to diet-induced microbiota shifts. ImportanceThe gut microbiome plays a critical role in various bodily functions, from the brains protective mechanisms to dietary behaviors and food choices. In this study, we sought to broaden the understanding of how various levels of high fat and high carbohydrate diet consumption alter gut microbiota, and ultimately, shape food preference behaviors. We assessed preference behaviors by categorizing rats into high-preference and low-preference groups based on their consumption of high calorie, palatable food, then analyzed their gut bacterial composition, comparing diet preference groups and examining whether sex differences were reflected in the results. The findings from this research hold significant implications for understanding the complex interplay between diet, microbiota, and behavior. Understanding the bidirectional relationship between feeding behavior and microbiota may provide novel insights into the mechanisms underlying eating disorders and metabolic dysregulation.

BackgroundTime-restricted eating (TRE) has gained popularity for weight loss and metabolic health. While some evidence suggests greater benefits when TRE aligns with circadian rhythms--characterized by early daytime eating and avoidance of nighttime intake, often referred to as early TRE (eTRE), other studies report no meaningful differences between eTRE, other TRE approaches with or without exercise, or calorie restriction (CR), and robust comparative evidence remains limited. AimTherefore, the aim of this network meta-analysis (NMA) is to evaluate the physiological effects of eTRE, midday time-restricted eating (mTRE), late time-restricted eating (lTRE), with and without exercise, CR, and control (without prescribed energy or fasting windows) on anthropometric measures and cardiometabolic markers in adults with cardiometabolic risk factors. MethodsA comprehensive literature search was conducted in four major databases (PubMed, Web of Science, Scopus, and Embase) up to April 24, 2025. A Bayesian NMA was performed, using a control group as the reference comparator across interventions. Treatment effects were expressed as mean differences with 95% confidence intervals. The relative ranking of the included arms on the outcomes was assessed using surface under the cumulative ranking curve, values derived from the NMA, where higher values reflect a higher probability of superior effectiveness. Resultsa total of 40 trials comprising 3259 subjects were included in the analysis. There were significant reductions in most anthropometric measures in all intervention groups compared to control group. Whereas eTRE and eTRE + exercise (EX) significantly improved glucoregulatory outcomes compared to control, eTRE + EX showed superior results over other interventions. ConclusionWhile our results did not detect statistically significant differences between TRE patterns and CR, the consistent SUCRA rankings in favor of eTRE (particularly with exercise) suggest that meal timing may play an important role in metabolic regulation.

Introduction. Ultra-processed foods (UPFs), defined as foods in group 4 of the NOVA classification system, are a key contributor to chronic disease in the United States. Front-of-package warning labels ('warnings') offer a promising strategy to help Americans reduce consumption of UPFs. Requiring warning labels on UPFs could help reduce consumption of these foods. However, the effects of UPF warnings are largely unknown. The impact of warning labels on UPFs among Latino adults was examined. Study design. Online randomized trial. Setting/participants. 4,107 Latino adults (49% limited English proficiency) in the US. Intervention. Participants viewed one of three labels: control labels displaying barcodes; identity warnings stating 'WARNING: Ultra-processed food'; or health warnings stating 'WARNING: Consuming ultra-processed food and drinks can cause weight gain, which increases the risk of obesity and type 2 diabetes'. Main outcome measures. Participants viewed four UPF products displaying their randomly assigned labels. Participants indicated whether the product was UPF (primary outcome) and rated perceived healthfulness of the product, intentions to purchase the product, and perceived message effectiveness (secondary outcomes). Results. Identity warnings (70% correct) and health warnings (67% correct) both led to higher correct identification of UPF compared to control labels (54%, p<.001), with the identity warning having a larger impact than the health warning (p=.007). Compared to the control label, the identity warning and health warning both elicited higher perceived message effectiveness and lower perceptions of healthfulness and purchase intentions (p<.001 for all outcomes) with no significant differences between UPF labels. The impact of the health warning label (vs. the control label) on correct identification of UPF was greater for participants with high education (p=0.012) compared to those with low education, and participants with limited English proficiency (p=0.001). Conclusions: UPF warnings may help consumers identify UPFs and influence product perceptions and intentions.

BackgroundEarly relational health (ERH) is thought to buffer the association between early life stress (ELS) and child psychopathology, but limited work has directly tested this hypothesis. ObjectiveWe evaluate mother-infant emotional connection, a facet of ERH, as a buffer of combined and individual impacts of specific ELS exposures (maternal mental health and interpartner conflict) on child psychopathology. MethodsParticipants included mother-infant dyads (n=100) followed longitudinally in the COMBO cohort, a convenience sample recruited during the COVID-19 pandemic. ERH was assessed via a remote mother-infant face-to-face interaction at ~4mo postpartum coded for emotional connection. An ELS Index was estimated using measures of maternal self-reported postpartum anxiety, depression, stress, and inter-partner conflict. Mothers rated emerging signs of child psychopathology symptoms at 2-3yrs on the Child Behavior Checklist for Ages 1[1/2]-5 (CBCL/1[1/2]-5). Main and interactive effects of ELS and ERH on emerging signs of child psychopathology were tested in generalized linear models. ResultsGreater ELS Index scores were associated with a higher rate of emerging psychopathology symptoms (aRR=1.32, p<.001), but this association was moderated by a significant interaction between the ELS Index and emotional connection (aRR=0.99, p=.03), such that at higher levels of emotional connection, the association of ELS with child psychopathology symptoms was weaker (aRR=1.16, p<.001). ConclusionParent-infant emotional connection may buffer the impact of ELS exposure in infancy on child emerging symptoms of psychopathology in toddlerhood, supporting efforts to invest in pediatric interventions that target ERH.