The study included 97 lunches recorded in two Swedish cities between October 2021 and November 2022. The recordings involved 92 children and 22 adults, comprising preschool teachers, child carers and trainee staff. The children ranged from one to six years old, the usual age range in Swedish preschools. The study focused on spontaneous verbal expressions of satiety; nonverbal indicators such as stopping eating or rubbing the stomach were outside its scope.

Researchers manually searched the video corpus for the Swedish word “mätt,” meaning “full,” and verbal variations of it. A case was counted as a new instance when the same child raised fullness in a later conversational sequence after a substantial interactional gap, or when another child raised the topic immediately. Talk that was not about the child’s own present satiety, including comments about other people, future fullness, drink-related fullness and pretend play, was excluded.

Forty-five of the 77 cases occurred as first turns, meaning the child introduced the topic without a preceding caregiver question. The other 32 arose as subsequent turns in response to a caregiver or, in some instances, another child. The most common caregiver responses involved repeating the child’s expression, acknowledging it or orienting to the next action in the meal. The researchers reported no observed pattern distinguishing responses to first-turn expressions from responses to subsequent-turn expressions.

The children’s expressions appeared shortly before the end of their meals. On average, children said they were full 27 minutes after beginning to plate their food; the median was 25 minutes, with observed times ranging from 12 to 41 minutes. The youngest children in the sample did not produce fullness expressions that the caregivers could understand, while children from approximately 2 years and 3 months through 6 years and 2 months did so in a form that could be interpreted.

Analysis of recorded conversations indicated that the expressions were not merely references to an individual physical state. Some children directed their statements toward a caregiver and repeated or reformulated them until they received an answer. Other children used fullness in response to questions or comments about food remaining on the table. The study’s discursive analysis treated these utterances as part of the social organization of a group meal, including the transition from eating to clearing the table and the management of food waste.

Most caregiver responses were consistent with what the researchers described as a responsive approach: adults generally acknowledged the child’s statement rather than claiming superior knowledge of the child’s internal state. A smaller number of episodes involved resistance or negotiation. In one case, a caregiver continued to focus on food left on a child’s plate after the child invoked fullness. In another, a caregiver repeatedly pressed a child who had said she was full to eat or drink more. The study therefore found variation within a broader pattern of acceptance, with adults sometimes treating fullness as a legitimate statement while still pursuing additional consumption.

The researchers assessed the videos and transcripts with descriptive statistics and discursive psychology, examining the timing, wording and interactional organization of children’s expressions. Transcriptions captured turn-taking, pauses, intonation and gestures, and all four authors checked the Swedish transcripts and their English translations. Because this was an observational study, it does not establish that caregiver responses caused changes in children’s eating behavior or later self-regulation.

Several limitations constrain the findings. The study measured what children said and how caregivers responded, not physiological satiety, and therefore cannot verify children’s internal states. It did not examine nonverbal fullness cues, and video recording may have influenced adult behavior despite the longitudinal collection period allowing some habituation. The analysis also did not control for dietary habits, preschool entry age, native language or other demographic factors. Results based on Swedish-language preschools in two cities may have limited generalizability to other settings.

Subject of Research: Qualitative study of children’s verbal satiety expressions and caregiver responses during Swedish preschool lunches

Article Title: Children’s verbal satiety expressions and caregivers’ responses during preschool mealtimes in Sweden

Article References: Nyberg-Akremi, S., Willemsen, A., Cromdal, J., & Wiggins, S. (2026). Children’s verbal satiety expressions and caregivers’ responses during preschool mealtimes in Sweden. BMC Psychology, 14(1), Article 1369. https://doi.org/10.1186/s40359-026-05650-8

Image Credits: AI Generated

DOI: 10.1186/s40359-026-05650-8

Keywords: preschool children, satiety expressions, responsive feeding, caregiver responses, mealtime interaction, qualitative observation, video analysis, Sweden, Children, verbal, satiety, expressions

Researchers Rhiannon Schultz of Animal Welfare Expertise and the University of Georgia, Isabella Clegg of Animal Welfare Expertise, and Roberta Salmi of the University of Georgia observed 21 male western lowland gorillas at five Association of Zoos and Aquariums-accredited institutions in the United States. The subjects ranged from five to forty years old and fell into four groups: adolescents, pubescents, healthy adults, and adults diagnosed with cardiovascular disease, a condition that disproportionately affects male gorillas in zoos and was included because reduced activity levels in heart-diseased animals might influence abnormal behavior. Over the period from May 2023 to January 2025, the team logged 1,034 hours of direct behavioral observation, using focal animal sampling and instantaneous scans at five-minute intervals to build detailed daily activity budgets for each individual.

The scale of observation matters, because previous studies of R&R often relied on small samples or on surveys of caretaker recollections rather than direct recording. By watching the animals themselves, the researchers could capture what happened immediately before each regurgitation event, what the animal had eaten beforehand, and how the behavior clustered in time. They also went beyond behavior into chemistry, analyzing the nutrient composition of the foods most often brought back up, using USDA databases and laboratory proximate analysis of dehydrated samples that measured crude protein, neutral detergent fiber, gross energy, and mineral content.

The results revealed a striking temporal pattern. R&R was overwhelmingly an afternoon affair. The statistical models showed the probability of the behavior at its lowest during the early morning hours of six to nine a.m., creeping upward through midday and peaking between three and six p.m. Even more telling was the relationship with feeding: the more time a gorilla spent feeding on a given day, the less likely it was to engage in R&R at all. This inverse correlation fits a hypothesis the researchers had set out to test, that the behavior may function as a way of extending feeding time when captive diets fail to satisfy the drives that wild feeding patterns normally fulfill.

That mismatch between wild and captive feeding is dramatic. Wild gorillas spend forty to fifty percent of their waking hours feeding and foraging on fibrous plant material, while zoo-housed gorillas dedicate at most twenty to twenty-five percent of their time to eating. Captive diets are nutrient-dense and low in fiber, meaning animals can consume their entire daily ration in a fraction of the time it would take to meet equivalent needs in a forest. The new study adds nuance to this picture: gorillas who structured their eating into longer, consolidated bouts followed by long gaps of inactivity showed higher R&R frequencies, while those with more fragmented feeding opportunities showed less. The behavior, in other words, appears tied not just to how much an animal eats, but to the rhythm of eating across the day.

The food chemistry results were perhaps the most surprising. Caretakers have long blamed fruit, with its sugar content and palatability, as the main trigger for R&R, and reduced-fruit diets have sometimes appeared to help. But this study found that commercial primate chow topped the list of foods disproportionately associated with the behavior, followed by fruit juice, grapes, cabbage, mixed nuts, and carrots. Only sycamore among the browse items was significant. Meanwhile, banana, broccoli, kale, and popcorn showed no association at all. Permutation-based nutrient comparisons showed that regurgitated foods tended to be richer in phosphorus, potassium, calcium, and magnesium, while fiber’s role proved more complicated than expected: some of the most regurgitated items, like chow and sycamore browse, were actually high in fiber.

The category-level analysis sharpened the contrast. Root vegetables carried more than a sixfold increase in the likelihood of being regurgitated relative to the baseline, chow and biscuits more than tripled the risk, and nuts, enrichment foods, and fruit each roughly doubled it. Browse, by contrast, was dramatically underrepresented: gorillas were about ninety-seven percent less likely to regurgitate browse than the reference category. Because browse items like leaves and stems demand long processing and chewing time, this finding suggests that foods requiring extended handling may protect against the behavior, while foods that can be gulped down quickly may leave the feeding drive unsatisfied. The researchers note that individual variation was considerable, with one gorilla regurgitating disproportionately after cabbage and another after oatmeal, suggesting diet design should work at the level of specific items rather than broad categories.

The behavioral sequence analysis revealed something equally important: R&R is not one uniform behavior but appears to come in at least two distinct forms. Isolated single events tended to follow periods of rest and inactivity, especially after sequences of resting followed by feeding, consistent with the old hypothesis that boredom or unmet foraging motivation triggers the behavior. Clustered bouts, in which animals repeated the cycle many times, were instead closely tied to feeding episodes, and only feeding occurred in the thirty-minute window preceding R&R episodes. A logistic decision-tree model identified high-risk sequences such as feeding transitioning into prolonged inactivity, and found that R&R itself predicted future R&R, hinting that in some individuals the behavior becomes self-reinforcing and potentially stereotypic.

Demographic patterns added another layer of intrigue, even if they were not statistically conclusive. Adults with heart disease showed the highest average time spent in R&R at about eighty minutes, and pubescents also showed elevated rates, though the study found no significant effect of demographic group overall and individual variability was high. The authors speculate that R&R may relate to metabolic or energetic demands that standard zoo diets, typically calculated from body weight, do not capture, particularly during growth or physiological change. They connect this to a broader metabolic picture: captive gorillas share risk factors with humans diagnosed with metabolic syndrome, including energy-dense, low-fiber diets, and these factors have been implicated in fibrosing cardiomyopathy, the leading heart disease of male zoo gorillas.

The practical implications are concrete. The authors suggest that breaking the day into more frequent, smaller feeding opportunities, ideally accompanied by low-sodium browse such as pear, American beech, or hackberry, could disrupt the long-bout-then-long-gap pattern that breeds clustered R&R. Predictive behavioral monitoring could flag risk windows in real time, allowing keepers to deploy enrichment or social opportunities before abnormal behavior emerges. The researchers caution that their study was observational and cannot establish causation, that physiological measures of hunger and satiety were not assessed, and that the sample, though larger than most previous work, was limited to males. Still, by dissecting R&R at the level of events, bouts, and episodes, and pairing behavior with nutrient chemistry, the study reframes this peculiar habit not as a meaningless quirk of captive life, but as a window into how environment and diet reshape the inner signals of hunger, fullness, and boredom in one of our closest relatives.

Subject of Research: Regurgitation and reingestion behavior in captive male western lowland gorillas and its dietary and behavioral triggers

Article Title: Abnormal ingestive behavior in male zoo gorillas: investigating the dietary and activity patterns associated with regurgitation and reingestion

Article References: Schultz, R. L., Clegg, I. L. K., & Salmi, R. (2026). Abnormal ingestive behavior in male zoo gorillas: investigating the dietary and activity patterns associated with regurgitation and reingestion. Frontiers in Ethology, 5, Article 1896803. https://doi.org/10.3389/fetho.2026.1896803

Image Credits: AI Generated

DOI: 10.3389/fetho.2026.1896803

Keywords: gorillas, animal welfare, regurgitation and reingestion, zoo nutrition, abnormal behavior, stereotypies, primate chow, browse, satiety, feeding behavior, captivity, ethology

The research, conducted by Marc Ballestero-Arnau and Toni Cunillera of the University of Barcelona’s Institute of Neurosciences, together with Borja Rodríguez-Herreros of the Centre Hospitalier Universitaire Vaudois in Lausanne, addressed a long-standing inconsistency in the literature on attentional bias. Attentional bias refers to the tendency of certain stimuli—threats, emotional faces, addictive substances, and especially palatable foods—to capture attention automatically, before conscious deliberation begins. Decades of work have linked such bias to overeating, yet studies examining how the bias changes with hunger, fullness, and body weight have produced conflicting results. Some experiments found that hungry participants attend more to food cues; others found no effect of hunger at all. The new study set out to resolve this confusion by manipulating metabolic state directly and measuring its interaction with BMI.

The methodological centerpiece of the work is the emotional attentional blink, a variant of a classic attention paradigm first described in the 1990s. In a rapid serial visual presentation, participants watch a fast stream of images and must detect a neutral target embedded within it. When an emotionally salient distractor appears shortly before the target, detection of the target drops sharply—the distractor effectively hijacks the attentional system for a few hundred milliseconds. By inserting photographs of real high-calorie foods as distractors at different points in the stream, the researchers could quantify how strongly food captured attention under different physiological conditions. Distractors appearing 300 milliseconds before the target, at so-called lag-3, probe the earliest and most automatic phase of attentional capture; distractors appearing 900 milliseconds before, at lag-9, serve as a comparison point when the blink has largely resolved.

The first experiment recruited 183 participants spanning the whole BMI range and randomly assigned them to one of three conditions. One group tasted the snacks without eating them to satiety, one group ate until satiated, and a third ate nothing at all. Crucially, the very snacks that participants had eaten—or had merely tasted or not encountered—later reappeared as distractors in the attentional task, allowing the researchers to test whether recent consumption of a specific food dampens its grip on attention. The results were unambiguous at the group level: food images presented at lag-3 significantly reduced target detection compared with lag-9, with an odds ratio of 0.61, confirming that real-food cues automatically captured attention regardless of metabolic state.

The most striking finding, however, emerged when BMI entered the statistical model. Higher body-mass index predicted a larger attentional bias when participants were hungry, but a smaller bias when they were satiated—an interaction reported with an odds ratio of 0.65 and a p-value below 0.01. In other words, hunger amplified the attentional pull of food most strongly in individuals with higher BMI, while satiety suppressed it more effectively in leaner individuals. This crossover pattern suggests that the metabolic signals of hunger and fullness do not act uniformly across the population; their influence on attention is calibrated, or miscalibrated, in ways that track body weight.

Because the first experiment could not fully separate hunger state from the type of food encountered, the team ran a second, more surgical experiment with 61 participants—31 with overweight or obesity and 30 of normal weight—across a double-session design. This time, hunger and satiety were manipulated orthogonally to snack type: participants encountered foods they had just consumed and foods that were entirely novel to the session. The results split cleanly along both dimensions. For novel foods, an interaction revealed that participants with overweight or obesity retained a robust attentional bias even after eating to satiation, whereas the bias declined for normal-weight participants once they were full, with an odds ratio of 2.45 and a p-value of 0.03.

For snacks that participants had just eaten, the picture changed in an unexpected way: the attentional bias remained significant in both weight groups, with lag-3 distractors producing far worse target detection than lag-9, at an odds ratio of 0.37 and a p-value below 0.001. This finding speaks to the phenomenon of sensory-specific satiety, the well-documented decline in the palatability of a food that has just been consumed. The behavioral expression of that satiety—the reduced desire to keep eating the same food—evidently does not translate into reduced automatic attention. A food can become less appealing to the palate while remaining fully capable of hijacking the earliest stages of visual attention, at least in the immediate aftermath of consumption.

Taken together, the two experiments sketch a model in which satiety signals alone are insufficient to curb attentional capture by food in obesity. In individuals with normal weight, the metabolic state of the body appears to gate the attentional system’s responsiveness to food cues: hunger opens the gate, fullness closes it. In individuals with overweight or obesity, that gating seems to fail for novel high-calorie foods, which continue to command attention even when the body has no need for energy. This dissociation between homeostatic signals and attentional orienting aligns with a broader theoretical framework in which the incentive salience of reward cues—their power to attract wanting, independent of pleasure or need—becomes exaggerated in obesity, potentially through altered function of dopaminergic reward circuitry.

The study also helps explain why previous findings in this field have been so inconsistent. Many earlier experiments relied on static food images viewed by participants in uncontrolled hunger states, or compared groups without manipulating satiety within the same individuals. By using real foods, experimentally induced hunger and satiety, and a temporally precise attention paradigm, the Barcelona team was able to detect interactions that simpler designs would average away. The authors’ own prior work had shown that food images capture attention by virtue of being food, independent of valence, arousal, appeal, or caloric content; the present study adds that this capture is not fixed but is modulated by the interplay of metabolic state and body weight.

The practical implications extend beyond the laboratory. If satiety cannot be relied upon to quiet attentional capture by food in individuals with higher BMI, then environments saturated with high-calorie cues—supermarket aisles, advertising screens, delivery apps—pose a persistent challenge that willpower deployed after a meal may be poorly equipped to meet. The authors suggest that interventions should target attentional control directly, through attention-bias modification training or similar approaches, and should limit food availability rather than trusting internal satiety signals to do the protective work. As obesity rates continue to climb worldwide, the study offers a sobering reframing: the battle against overeating may be lost or won not at the level of conscious craving, but in the first few hundred milliseconds after a pizza advertisement flickers across the visual field.

Subject of Research: Modulation of food-related attentional bias by hunger, satiety, and body-mass index

Article Title: Satiety does not always silence attention to high-calorie foods: BMI modulates food-related attentional bias

Article References: Ballestero-Arnau, M., Rodríguez-Herreros, B., & Cunillera, T. (2026). Satiety does not always silence attention to high-calorie foods: BMI modulates food-related attentional bias. International Journal of Obesity. https://doi.org/10.1038/s41366-026-02240-x

Image Credits: AI Generated

DOI: 10.1038/s41366-026-02240-x

Keywords: attentional bias, obesity, body-mass index, satiety, hunger, high-calorie foods, emotional attentional blink, sensory-specific satiety, attentional capture, eating behavior, reward circuitry, cognitive control